Site Sponsors
Results 1 to 36 of 36

Thread: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

  1. #1
    Senior Member
    Join Date
    May 2009
    Location
    Marseille, FRANCE
    Posts
    1,041
    Post Thanks / Like

    best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    I'm using shift lenses 99% of time... i have an A7R3 (i will upgrade later to A7R4 and GFX50r)
    Similar post in the Sony forum... because i need Sony A7r owners point of view as well...

    Still no modern 35mm shift to fill the gap between 24 TS-e II and 50 TS-e...

    I've done my homework and it looks like the best option are :

    - Zeiss contax 645... but with fixed aperture... don't like it
    - Zeiss Contax PC distagon
    - Pentax 645 HD DFA last D version with manual aperture ring mounted on a shift adapter (i'm think of pentax 645 to Canon shift adapter in order to be able to use the lens with Sony A7r≈ and Fuji GFX.

    For best quality, what will you recommend ?

  2. #2
    Senior Member Abstraction's Avatar
    Join Date
    Feb 2016
    Posts
    524
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    What about Canon FD 35mm TSE lens?

  3. #3
    Senior Member
    Join Date
    May 2009
    Location
    Marseille, FRANCE
    Posts
    1,041
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by Abstraction View Post
    What about Canon FD 35mm TSE lens?
    from my readings... not good enought...

  4. #4
    Member
    Join Date
    Jul 2019
    Posts
    146
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    I have owned and used the Canon FD 35mm t/s lens (twice). I used it on a Sony A7R. For its age, it's a good lens -- well made, easy to use, decent performance. However, it doesn't hold up well against many other options.

    Also on an A7R I've used the SMC Pentax-A 645 35mm f/3.5. It was a very good performer. I'm now using a second one on a Fuji GFX 50R. I have not found a better option for the 35mm focal length that works on the Fuji and my tech camera (Toyo VX23D).

    You asked about the latest D version. I haven't used it, but I have read favourable reviews. Apparently the coatings are a bit better. I trust you've been to the Pentaxforums user review page? Their reviews are quite useful (in the aggregate).

    I have used the 35mm FA 645 lens. I compared it side-by-side to the A version and kept the A. In my comparison, the centre was a touch better in the FA, but the edges were a bit worse. Given that I needed it to work as a shift lens, that knocked the FA out of contention.

    On a GFX sensor you'll get 8mm of good quality shift performance from the 35mm Pentax 645 lens. A shift of 10mm is only advisable if there's little or no detail in the far shifted areas (e.g., sky above a building). 12mm is of course possible if the adapter supports it, but things can get soft and mushy at the far shifted edge. Of course you get a lot more shift on an A7R_ sensor; if I remember correctly, I was confidently making 12mm shifts.

    The Zeiss Contax PC Distagon has many fans. However, the image circle is only 63mm (according to Zeiss), meaning that shift potential on my GFX 50R is really marginal. In comparison, the Pentax 645 lenses have an image circle of roughly 72mm.

    Here is a link to a full resolution JPEG file of a 12mm rise on a Fuji GFX 50R using the SMC Pentax-A 35mm f/3.5 (shot at f/16). Apart from Lightroom's default sharpening, nothing has been done to the file. https://drive.google.com/open?id=193...WcfXD3pMI_9exE
    Thanks 1 Member(s) thanked for this post
    Likes 2 Member(s) liked this post

  5. #5
    Senior Member
    Join Date
    May 2009
    Location
    Marseille, FRANCE
    Posts
    1,041
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by rdeloe View Post
    Here is a link to a full resolution JPEG file of a 12mm rise on a Fuji GFX 50R using the SMC Pentax-A 35mm f/3.5 (shot at f/16). Apart from Lightroom's default sharpening, nothing has been done to the file. https://drive.google.com/open?id=193...WcfXD3pMI_9exE
    Thanks for that !

  6. #6
    Super Duper
    Senior Member

    Join Date
    Mar 2009
    Posts
    4,130
    Post Thanks / Like
    Images
    1

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Just a quick comment regarding the Pentax 35mm FA 645 lens, specifically related to it's performance on the 645D and 645Z. Over the years I've tested possibly more than 16 samples of this lens (first described years back here on Getdpi in my so called lens testing compendium of Pentax 645 lenses tested on the 645D body and although there was sample variation, the one consistent property of that lens was extreme and excessive field curvature, especially at longer distances approaching infinity. Although center sharpness was good, sides and edge sharpness was poor and it was near impossible to get edge to edge sharpness in a landscape image. As one shot a closer subject, this field curvature would be reduced and less evident. One way to partially get around this field curvature at infinity, this was to adjust front/back focus in the digital body, pushing back the depth of field and thus the apparent curvature, so that at infinity, the center would decrease somewhat in sharpness but the sides/edges would sharpen up. Not ideal of course. The "A" lens in this regard was far superior.

    Enter the somewhat revised newer Pentax D FA 35mm 645 lens. Except for the somewhat difference in black color of the lens barrel, for all intent and purposes, the lens appears identical to the original FA 35mm 645, including its optical arrangement. Pentax except for changing the designation of the name from FA to D FA, never denoted any difference between the two and most assumed "maybe" it was simply a change in coatings. Upon testing the newer version (the D FA), I was astonished at the changes. The lens was tact sharp (even at 100%), edge to edge. At f3.5 wide open maybe a hair touch of softness, but again very even across the frame and stopping down to f4 and beyond, extremely sharp edge to edge. Most of not all of the field curvature is gone. I've since had the opportunity to try 3 more samples of the revised D FA version, and they all exhibit this massive improvement over the original. It took considerable time and attempts at correspondence with Pentax, and from what I can gleam is that an aspherical element in the original FA version, was redesigned which resulted in addressing the field curvature. Less certain is newer coatings on glass surfaces, that appears to have resulted in increased contrast of the lens which is noticeable. I'd go so far to say, it's now easily takes the position of the best of the three Pentax 35mm 645 lens, putting the manual focus "A" version behind the newest one by a noticeable margin. The "A" version which is still a extremely fine lens and is considerable less expensive. How the D FA version would fair as a shift lens, I cannot speak to that. Hope this info is of some help.

    Dave (D&A)
    Last edited by D&A; 8th November 2019 at 18:16.
    Thanks 1 Member(s) thanked for this post
    Likes 1 Member(s) liked this post

  7. #7
    Member
    Join Date
    Jul 2019
    Posts
    146
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Fantastic update Dave. Thank you! You confirm -- through actual experience -- a bunch of things that I'd read on the 'net but wasn't sure were well-founded.

    I almost owned a D-FA. The seller advertised it as an FA and nobody was interested. At the last moment, just before it would have been too late for him, he realized his error and pulled the auction! Grrr.

    If I ever get a D-FA, I will probably instantly become unsatisfied with my A. In the meantime though, the A version remains an excellent choice for my needs.

    For context though, I'm also very happy with the SMC Pentax 67 45mm f/4, which is not as sharp as the SMC Pentax-A 35mm f/3.5. Nonetheless, I love the angle of view of the 45mm lens on my GFX 50R. And once I distance myself from test charts and side-by-side comparisons, I'm extremely happy with the photographs it makes. Plus it's an excellent shift lens because of the significantly larger image circle. As is always the case, there's more to a lens than just one thing like sharpness.

    Cheers, Rob


    Quote Originally Posted by D&A View Post
    Just a quick comment regarding the Pentax 35mm FA 645 lens, specifically related to it's performance on the 645D and 645Z. Over the years I've tested possibly more than 16 samples of this lens (first described years back here on Getdpi in my so called lens testing compendium of Pentax 645 lenses tested on the 645D body and although there was sample variation, the one consistent property of that lens was extreme and excessive field curvature, especially at longer distances approaching infinity. Although center sharpness was good, sides and edge sharpness was poor and it was near impossible to get edge to edge sharpness in a landscape image. As one shot a closer subject, this field curvature would be reduced and less evident. One way to partially get this field curvature at infinity, this was to adjust front/back focus in the digital body, pushing back the depth of field and thus the apparent curvature, so that at infinity, the center would decrease somewhat in sharpness but the sides/edges would sharpen up. Not ideal of course. The "A" lens in this regard was far superior.

    Enter the somewhat revised newer Pentax D FA 35mm 645 lens. Except for the somewhat difference in black color of the lens barrel, for all intent and purposes, the lens appears identical to the original FA 35mm 645, including its optical arrangement. Pentax except for changing the designation of the name from FA to D FA, never denoted any difference between the two and most assumed "maybe" it was simply a change in coatings. Upon testing the newer version (the D FA), I was astonished at the changes. The lens was tact sharp (even at 100%), edge to edge. At f3.5 wide open maybe a hair touch of softness, but again very even across the frame and stopping down to f4 and beyond, extremely sharp edge to edge. Most of not all of the field curvature is gone. I've since had the opportunity to try 3 more samples of the revised D FA version, and they all exhibit this massive improvement over the original. It took considerable time and attempts at correspondence with Pentax, and from what I can gleam is that an aspherical element in the original FA version, was redesigned which resulted in addressing the field curvature. Less certain is newer coatings on glass surfaces, that appears to have resulted in increased contrast of the lens which is noticeable. I'd go so far to say, it's now easily takes the position of the best of the three Pentax 35mm 645 lens, putting the manual focus "A" version behind the newest one by a noticeable margin. The "A" version which is still a extremely fine lens and is considerable less expensive. How the D FA version would fair as a shift lens, I cannot speak to that. Hope this info is of some help.

    Dave (D&A)

  8. #8
    Super Duper
    Senior Member

    Join Date
    Mar 2009
    Posts
    4,130
    Post Thanks / Like
    Images
    1

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by rdeloe View Post
    Fantastic update Dave. Thank you! You confirm -- through actual experience -- a bunch of things that I'd read on the 'net but wasn't sure were well-founded.

    I almost owned a D-FA. The seller advertised it as an FA and nobody was interested. At the last moment, just before it would have been too late for him, he realized his error and pulled the auction! Grrr.

    If I ever get a D-FA, I will probably instantly become unsatisfied with my A. In the meantime though, the A version remains an excellent choice for my needs.

    For context though, I'm also very happy with the SMC Pentax 67 45mm f/4, which is not as sharp as the SMC Pentax-A 35mm f/3.5. Nonetheless, I love the angle of view of the 45mm lens on my GFX 50R. And once I distance myself from test charts and side-by-side comparisons, I'm extremely happy with the photographs it makes. Plus it's an excellent shift lens because of the significantly larger image circle. As is always the case, there's more to a lens than just one thing like sharpness.

    Cheers, Rob
    Don't get me wrong...the "A" version is an excellent lens and unless you have the need to print quite large and need all the sharpness possible across the entire frame, the "A" lens price/performance wise is to be strongly considered. Couldn't agree more....there is more to a lens than simply sharpness. If that wasn't so, there wouldn't be a host of older Leica classic lenses (among other brands) that are highly prized for the way they draw as opposed to absolute razor sharpness edge to edge.. There's room for both.

    Makes sense that the larger image circle of a Pentax 67 lens on the current 50MP sensor, would have a distinct advantage.

    Dave (D&A)
    Last edited by D&A; 8th November 2019 at 09:43.

  9. #9
    Senior Member
    Join Date
    May 2009
    Location
    Marseille, FRANCE
    Posts
    1,041
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    That Pentax 645 HD seems good... i will probably go this way !

    by the way, will it make any difference to buy a P645/EOS adapter + Eos/GFX shift... over the Kipon P645/GFX shift ?
    What's the best solution considering flare and movements ?




    - Zeiss 35mm contax 645... fixed aperture... if you put the lens on a contax body, fix it to F11 and removing if... will it stay at F11 for ever ?

    I must confess that while i'm fond of lens movements ans sharpness... i'm also a big fan of contax lenses and their color rendition !

  10. #10
    Senior Member
    Join Date
    Feb 2011
    Location
    W. NY, close to Toronto, far from NYC
    Posts
    1,664
    Post Thanks / Like
    Images
    17

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Dave has done more testing of Pentax 645 lenses than anyone I've encountered. My own experience with A and FA versions (not DFA) is consistent with what's been said. The A version remains quite a bargain. Related observation: I recently tried the last version of the 67 55mm f/4 on a 50R using a Fotodiox shift adapter and the results are excellent, at least equal, if not surpassing the Fuji 32-55mm, while allowing tilt and shift. Archivue, I will be selling a Zoerk shift adapter (Pentax 645 to Canon) if interested, PM me.

    Tom
    Thanks 1 Member(s) thanked for this post
    Likes 1 Member(s) liked this post

  11. #11
    Member
    Join Date
    Jul 2019
    Posts
    146
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by tsjanik View Post
    Dave has done more testing of Pentax 645 lenses than anyone I've encountered. My own experience with A and FA versions (not DFA) is consistent with what's been said. The A version remains quite a bargain. Related observation: I recently tried the last version of the 67 55mm f/4 on a 50R using a Fotodiox shift adapter and the results are excellent, at least equal, if not surpassing the Fuji 32-55mm, while allowing tilt and shift. Archivue, I will be selling a Zoerk shift adapter (Pentax 645 to Canon) if interested, PM me.

    Tom
    I can second the vote for P67 55mm f/4 (latest edition only). It is an extremely good performer. I didn't keep my copy is it's very heavy, and I'm very happy with the performance of the 60mm EL I'm using. However, if I needed that focal length, that's what I'd use.

  12. #12
    Senior Member
    Join Date
    May 2009
    Location
    Marseille, FRANCE
    Posts
    1,041
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    I've test the CONTAX 35 PC... and wasn't impress at all...
    I've seen some sample made with the Pantax D, not perfect also...

    Do you think that using the Contax 645 35mm fixed at f11 with a shift adaptor could be better ?

  13. #13
    Senior Member
    Join Date
    Feb 2009
    Location
    Scottsdale, AZ
    Posts
    631
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by archivue View Post
    I've test the CONTAX 35 PC... and wasn't impress at all...
    I've seen some sample made with the Pantax D, not perfect also...

    Do you think that using the Contax 645 35mm fixed at f11 with a shift adaptor could be better ?
    Of course, the C645 35mm lens isn't perfect, either. But if you like the Zeiss look -- and I certainly do! -- it's the only option available at that focal length...

    What subject matter will you be photographing and how will you use the movements?

    I ask, because I have a C645 35mm lens that I use as a fixed-aperture shift lens on my A7R for photographing urban and suburban street and alley scenes, which often include a significant architectural element in the compositions, and it will display a small amount of "mustache" distortion that is difficult to eliminate entirely even when using post-exposure correction software (including Alpa's correction software and profile, alas.)

    While I'm usually okay with this, because no lens is perfect and I very much like the performance of this lens otherwise, if you use the lens to stitch a larger / wider file instead of to apply rise / fall movements to correct for keystoning, you may sometimes see very small amounts of ripple in straight lines that run across the frame from side-to-side and/or slightly lower resolution along the stitch lines, because the software has to massage the pixels a bit in order to align the files.

    For the most part, I'm okay with this, too, because I'm not really photographing the structures in the photo but the scene overall, so rendering the structures with geometric perfection isn't my primary goal. But some photographers -- and, I suspect, clients -- are not, hence you should at least be aware of this effect.

    On my sample, at least, the image quality holds up surprisingly well out to very near the edge of the image circle -- see, for example, the structure at the top of this grain elevator photographed with ~19 mm of rear rise, which is about the maximum possible on my A7R before the vignetting becomes visible, as it's just starting to do here:



    Here's another grain elevator photo, taken with slightly less rear rise -- ~17 mm, IIRC -- hence less vignetting is visible:



    As I wrote, even though using the C645 lenses with fixed apertures is a PITA (because I photograph a lot at night, so I have to compose and focus wide-open, then remove the lens to stop down the aperture [using a small A5100 body / Fringer / NAM-1 adapter combo I carry with me for this purpose] then remount it on my modified FrankenKameras [i.e., fancy shift and tilt/shift lens adapters I've made from other cameras] without altering its focus [which I sometimes end up having to tweak slightly afterward regardless] or even worse, dropping it), the results are usually worth the additional effort, especially as these lenses can be purchased quite affordably these days.

    That said, YMMV, because the GFX sensor is larger than my A7R's sensor, hence your range of acceptable rise / fall / shift movements with it will be proportionally shorter than mine. Alas, I am not aware of anyone else who is using a GFX body with this lens for shift movements, so you may well have no choice but to boldly go where no photographer has gone before...
    Likes 1 Member(s) liked this post

  14. #14
    Member
    Join Date
    Nov 2010
    Location
    Munich/Guangzhou
    Posts
    165
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by archivue View Post
    I've test the CONTAX 35 PC... and wasn't impress at all...
    I've seen some sample made with the Pantax D, not perfect also...

    Do you think that using the Contax 645 35mm fixed at f11 with a shift adaptor could be better ?
    Yes I think so.
    IMO the Contax 645 35f3.5 is the second best 35mm lens with large image circle after the blue ring P1 35f3.5.

    I don't use it very often on my GFX but I found three samples with the GFX50s.
    The corner crop of the second sample shows the good corner sharpness at (possibly) full shift of 15mm with the Mirex adapter.
    The lens is pre-set to f11.
    Click image for larger version. 

Name:	2048_DSF9658.jpg 
Views:	66 
Size:	599.9 KB 
ID:	145479Click image for larger version. 

Name:	2048_DSF9658_crop.jpg 
Views:	38 
Size:	726.1 KB 
ID:	145480Click image for larger version. 

Name:	2048_DSF9763c.jpg 
Views:	13 
Size:	820.2 KB 
ID:	145481Click image for larger version. 

Name:	2048_DSF9763c_crop.jpg 
Views:	29 
Size:	614.0 KB 
ID:	145482
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	2048_DSF9410.jpg 
Views:	41 
Size:	735.4 KB 
ID:	145477   Click image for larger version. 

Name:	2048_DSF9410_crop.jpg 
Views:	15 
Size:	715.9 KB 
ID:	145478  

  15. #15
    Senior Member
    Join Date
    Feb 2009
    Location
    Scottsdale, AZ
    Posts
    631
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by chrismuc View Post
    Yes I think so.
    IMO the Contax 645 35f3.5 is the second best 35mm lens with large image circle after the blue ring P1 35f3.5.

    I don't use it very often on my GFX but I found three samples with the GFX50s.
    Okay, I should have known there had to be someone, somewhere using a C645 / Fuji combo better, hence I now stand corrected. <blushes>

  16. #16
    Subscriber and Workshop Member MGrayson's Avatar
    Join Date
    Nov 2010
    Location
    NYC
    Posts
    2,570
    Post Thanks / Like
    Images
    4

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    This is a great idea. I've been using the Canon 24mm TS-E on the GFX, but I have the Contax 645 35mm already, and that has a much larger image circle. Plus 24mm shifted on a 44x33mm sensor is a pretty wide lens. Nice to have a less extreme option.

    Matt

  17. #17
    Member
    Join Date
    Nov 2010
    Location
    Munich/Guangzhou
    Posts
    165
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Two more things to mention:

    1
    I use the Mirex Contax 645 - Canon EF shift adapter in combination with a Fotodiox Canon EF - Fujifilm GF adapter. But the Mirex is (as far as I know) no longer in production. For Hasselblad CF lenses I use a Kipon HB CF - Fujifilm GF shift adapter.
    Currently I think the Kipon Contax 645 - Fujifilm GF shift adapter is the only one available for that purpose.
    https://www.adorama.com/kasgfxcx645....hredirect=true

    2
    The Contax 645 35f3.5 lens has a total image circle of 84 mm and a sharp image circle of 78 mm (acc. my tests). This basically allows to use full 15mm shift in any direction.

  18. #18
    Member
    Join Date
    Dec 2014
    Posts
    57
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    I would like to revive this thread because I think about buying the Pentax 35mm lens for shift use on the GFX 100. Three questions:

    1. Is this the latest version of the lens? HD PENTAX-D FA 645 35mm F3,5 AL [IF]

    2. From the information I could find I was not sure if the aperture can be controlled manually when I use a dumb shift adapter. It has an aperture ring, but this ring has an "A"-position which often is an indication that the aperture is controlled electronically via the body. Can anybody confirm aperture can be controlled without a pentax body?

    3. Can anyone provide a sample image with this lens when used with a serious amount of shift on a GFX body? GFX 100, or one of the 50MP bodies. Complete image or 100% crops. Whatever you have would be helpful.

    Thanks -
    Marc

  19. #19
    Member
    Join Date
    Jul 2019
    Posts
    146
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by marc aurel View Post
    I would like to revive this thread because I think about buying the Pentax 35mm lens for shift use on the GFX 100. Three questions:

    1. Is this the latest version of the lens? HD PENTAX-D FA 645 35mm F3,5 AL [IF]

    2. From the information I could find I was not sure if the aperture can be controlled manually when I use a dumb shift adapter. It has an aperture ring, but this ring has an "A"-position which often is an indication that the aperture is controlled electronically via the body. Can anybody confirm aperture can be controlled without a pentax body?

    3. Can anyone provide a sample image with this lens when used with a serious amount of shift on a GFX body? GFX 100, or one of the 50MP bodies. Complete image or 100% crops. Whatever you have would be helpful.

    Thanks -
    Marc
    Marc,

    1. Yes, the one you named is the latest one: https://www.pentaxforums.com/lensrev...-f35-alif.html.

    2. Yes, manual aperture control. You can see the aperture ring in the picture at the above link. You're wise to ask because some of the most modern ones cannot. For example, neither of the two flavours of the 25mm lens can be controlled manually; you need a Pentax body.

    3. Check out this thread: https://www.dpreview.com/forums/thread/4464772?page=2 Scroll down to find the post by Antonio Chagin. He was looking at this exact scenarios, and bought the lens you're interested. He posted some RAW files he made shifted, but I notice they're gone now. If you contact him directly he might be able to provide them for you.

    If you're willing to consider the 35mm A version, I can provide some RAFs on the 50R that show shift performance. Honestly, it's an excellent lens for a fraction of the price of its newer sibling.

    Rob

  20. #20
    Member
    Join Date
    Dec 2014
    Posts
    57
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by rdeloe View Post
    Marc,

    1. Yes, the one you named is the latest one: https://www.pentaxforums.com/lensrev...-f35-alif.html.

    2. Yes, manual aperture control. You can see the aperture ring in the picture at the above link. You're wise to ask because some of the most modern ones cannot. For example, neither of the two flavours of the 25mm lens can be controlled manually; you need a Pentax body.

    3. Check out this thread: https://www.dpreview.com/forums/thread/4464772?page=2 Scroll down to find the post by Antonio Chagin. He was looking at this exact scenarios, and bought the lens you're interested. He posted some RAW files he made shifted, but I notice they're gone now. If you contact him directly he might be able to provide them for you.

    If you're willing to consider the 35mm A version, I can provide some RAFs on the 50R that show shift performance. Honestly, it's an excellent lens for a fraction of the price of its newer sibling.

    Rob
    Hi Rob,

    thanks a lot for your detailed information. Very helpful - and the answers are what I hoped for too ;-)
    I read that the newer edition of the lens was even better. And since I go for ultimate quality in the GFX system I will try that. I will try to contact Antonio.

    Best -
    Marc

  21. #21
    Member
    Join Date
    Jul 2019
    Posts
    146
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by marc aurel View Post
    Hi Rob,

    thanks a lot for your detailed information. Very helpful - and the answers are what I hoped for too ;-)
    I read that the newer edition of the lens was even better. And since I go for ultimate quality in the GFX system I will try that. I will try to contact Antonio.

    Best -
    Marc
    Makes sense. Good luck. If you do get one, I'll be curious to know what you think. I use this focal length a lot, and if I hear some more reports that it's superb, I may have to break down and get one too!

  22. #22
    Super Duper
    Senior Member

    Join Date
    Mar 2009
    Posts
    4,130
    Post Thanks / Like
    Images
    1

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Hi, as I mentioned and outlined in my post "above" (in this thread), the Pentax HD D-FA 35mm f3.5 is heads and shoulders above it predecessor, the FA 35mm f3.5 . These observations are based on multiple testing of many samples of each lens on initially the Pentax 645D and subsequently, the 645Z. I've relied on others observations, regarding how these lenses performed when shifted.

    Dave (D&A)
    Last edited by D&A; 23rd May 2020 at 03:35.

  23. #23
    Member
    Join Date
    Jun 2015
    Posts
    39
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by marc aurel View Post
    I would like to revive this thread because I think about buying the Pentax 35mm lens for shift use on the GFX 100. Three questions:

    1. Is this the latest version of the lens? HD PENTAX-D FA 645 35mm F3,5 AL [IF]

    2. From the information I could find I was not sure if the aperture can be controlled manually when I use a dumb shift adapter. It has an aperture ring, but this ring has an "A"-position which often is an indication that the aperture is controlled electronically via the body. Can anybody confirm aperture can be controlled without a pentax body?

    3. Can anyone provide a sample image with this lens when used with a serious amount of shift on a GFX body? GFX 100, or one of the 50MP bodies. Complete image or 100% crops. Whatever you have would be helpful.

    Thanks -
    Marc
    Marc, PM me your email address and I'll send you RAW files taken with the A and GFX100, shifted on a Kipon adapter.

  24. #24
    Member
    Join Date
    Jun 2015
    Posts
    39
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by archivue View Post
    That Pentax 645 HD seems good... i will probably go this way !

    by the way, will it make any difference to buy a P645/EOS adapter + Eos/GFX shift... over the Kipon P645/GFX shift ?
    What's the best solution considering flare and movements ?
    You can actually combine the Kipon P645-EOS shift adapter with their EOS-GFX shift adapter and have dual movements. So, shift up and then stitch left to right. The 35mm is very resistant to flare (I've owned the A and FA, both are great), but any shift adapter may improve with a little flocking.

  25. #25
    Member
    Join Date
    Jun 2015
    Posts
    39
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by D&A View Post
    Hi, as I mentioned and outlined in my post "above" (in this thread), the Pentax HD D-FA 35mm f3.5 is heads and shoulders above it predecessor, the FA 35mm f3.5 . These observations are based on multiple testing of many samples of each lens on initially the Pentax 645D and subsequently, the 645Z. I've relied on others observations, how these lenses performed when shifted.

    Dave (D&A)
    Dave, have you noticed any differences in that odd distortion profile when shifted, particularly along the long edge? It's because of that I'm using the Canon 24mm in crop mode on the GFX100 rather than the 35mm, and then the 32-64 whenever shift isn't required. For commercial interiors any distortion is clearly visible and makes the A/FA hard to work with.

  26. #26
    Super Duper
    Senior Member

    Join Date
    Mar 2009
    Posts
    4,130
    Post Thanks / Like
    Images
    1

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by Owen View Post
    Dave, have you noticed any differences in that odd distortion profile when shifted, particularly along the long edge? It's because of that I'm using the Canon 24mm in crop mode on the GFX100 rather than the 35mm, and then the 32-64 whenever shift isn't required. For commercial interiors any distortion is clearly visible and makes the A/FA hard to work with.
    Hi Owen. Unfortunately I haven't had the opportunity to test any of the three Pentax medium format 645 lenses (the "A", FA or HD D-FA) in a "shift" scenario....if I understand your question correctly. I could surmise (based on my experience with shifting with lens and shift adaptor but unfortunately that was not with any of the three Pentax 35mm 645 lenses being discussed. I would guess the "FA" version might be most problematic at full shift. It's interesting to note that optical properties of field curvature and distortion generally seen with the "FA" version is very different than with the "A" version...whereby the former has excessive (almost extreme in my opinion especially when lens focused at infinity) field curvature as opposed to some quite mild mustache type waviness distortion in the "A" version. What effect both these observations will have on either the short or long side when either these lenses are fully shifted, can only be determined when actually tried.

    If I was a person contemplating use of one of these lenses adapted for shift use on the Fuji, my order of preference in trying them would be the HD D-FA and then the "A" version...the latter which for the money is a exceptionally good lens except for a bit of weakness along the short side edges and the mild distortion as mentioned. I feel I haven't been of much help with regards to definitively saying anything about each lenses potential as a shift lens but I am extremely curious. As a side note, it's interesting how the "FA" and HD D-FA lenses appear almost if not identical in both appearance and optical arrangement yet remarkably difference in performance. The increase in contrast is noticeable and is probably due to a change in coatings and the dramatic performance boost in almost eliminating its extremely field curvature, I put down to what info I have gleaned....that the aspherical element was re-computated as a primary change. It truly resulted in a remarkable change in performance.

    It's interesting to note, that Pentax through the years never really touted unique optical parameters of their lenses as some other 35mm companies often did. A number of their high performing 35mm lenses contained aspherical elements in the days before they were commonly used in 35mm format lenses, yet Pentax never said a word in advertising. That conservative approach stayed with them almost until the time they were acquired by Ricoh, so it's no surprised that little is mentioned about the differences between the older "FA" version and current HD D-FA and yet the differences are quite dramatic, especially when files are examined or utilized at full resolution.

    Dave (D&A)

  27. #27
    Member
    Join Date
    Jul 2019
    Posts
    146
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by Owen View Post
    Dave, have you noticed any differences in that odd distortion profile when shifted, particularly along the long edge? It's because of that I'm using the Canon 24mm in crop mode on the GFX100 rather than the 35mm, and then the 32-64 whenever shift isn't required. For commercial interiors any distortion is clearly visible and makes the A/FA hard to work with.
    I use the SMC Pentax-A 645 35mm f/3.5 as a shift lens.

    Unshifted, there's barrel distortion, which tidies up cleanly in Lightroom. I should really build a custom profile, but haven't done so. In the meantime, the FA profile works well for both vignetting and distortion (likely because I mostly shoot things that don't display the distortion).

    The distortion shape changes to what looks like pincushion in the top 1/3rd when you make a 10mm plus vertical shift in portrait mode (in other words, a rise). However, what really happening is you're seeing one side of the mustache. Thus, the barrel distortion you see unshifted is the middle part of the mustache shape. On a sensor that covered the entire image circle as it was meant to be used, you'd see the full mustache form, which you don't see unshifted using a 33mm x 44mm sensor.

    With a 5mm rise in portrait orientation, the problem I described for the 10mm plus shift is present, but to a much lesser extent. Except for the most demanding cases, the built-in tools provided by Lightroom clean things up nicely.

    Needless to say, the shifted distortion form visible at 10mm and larger shifts is not easily correctable. If you're shooting landscapes or other scenes where you don't have regular, straight shapes aligned with the edge of the frame, it's not really a problem. But for architectural or interior work, I could see it being problematic.

  28. #28
    Member
    Join Date
    Dec 2014
    Posts
    57
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by rdeloe View Post
    I use the SMC Pentax-A 645 35mm f/3.5 as a shift lens.

    Unshifted, there's barrel distortion, which tidies up cleanly in Lightroom. I should really build a custom profile, but haven't done so. In the meantime, the FA profile works well for both vignetting and distortion (likely because I mostly shoot things that don't display the distortion).

    The distortion shape changes to what looks like pincushion in the top 1/3rd when you make a 10mm plus vertical shift in portrait mode (in other words, a rise). However, what really happening is you're seeing one side of the mustache. Thus, the barrel distortion you see unshifted is the middle part of the mustache shape. On a sensor that covered the entire image circle as it was meant to be used, you'd see the full mustache form, which you don't see unshifted using a 33mm x 44mm sensor.

    With a 5mm rise in portrait orientation, the problem I described for the 10mm plus shift is present, but to a much lesser extent. Except for the most demanding cases, the built-in tools provided by Lightroom clean things up nicely.

    Needless to say, the shifted distortion form visible at 10mm and larger shifts is not easily correctable. If you're shooting landscapes or other scenes where you don't have regular, straight shapes aligned with the edge of the frame, it's not really a problem. But for architectural or interior work, I could see it being problematic.
    Good information. Thank you for that. Would have been great if the lens had barrel distortion all over. Moustache distortion ;-(
    Unfortunately no program I know has profiles for Pentax 645 lenses. Neither Capture One nor the Alpa plugin for photoshop. But if you shoot architecture for custumors then an uncorrected image is a no go. So what to do if you want to use that lens?

    The only way I can think of to correct the moustache distortion on this lens with more than a few millimeters of shift would be:
    - open in Photoshop
    - expand canvas to a size that covers the whole image circle of the lens (using the maximum shift you want to use)
    - move your image in the expanded canvas until the optical centre of the lens is in the middle (you can create actions in PS to do those tasks)
    - save to lightroom
    - then you need a custom made profile for the Pentax lens with your expanded canvas to apply it to that image in LR. Then crop back to the original image size.
    - this profile can be made using adobe lens profile creator.
    - but for that you need at least nine images of a test target with different amounts of shift in different direction.
    - every image must be expanded to the canvas size that covers the whole image circle of the lens
    - very time consuming process

    So would the sharpness of the lens in comparison to other options be worth all that work? I am not sure. The shifted Contax 645 35mm lens can easily be corrected with provided profiles in C1 and the Alpa plugin. This is an advantage of the Contax. Its disadvantage is that you can only use it with fixed aperture if you want to shift.

    As was mentioned by others: cropping the TS-E 24mm is an option too. Would be interesting to see a comparison between these 3 options.

    Best - Marc

  29. #29
    Member
    Join Date
    Jul 2019
    Posts
    146
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by marc aurel View Post
    Good information. Thank you for that. Would have been great if the lens had barrel distortion all over. Moustache distortion ;-(
    Unfortunately no program I know has profiles for Pentax 645 lenses. Neither Capture One nor the Alpa plugin for photoshop. But if you shoot architecture for custumors then an uncorrected image is a no go. So what to do if you want to use that lens?

    The only way I can think of to correct the moustache distortion on this lens with more than a few millimeters of shift would be:
    - open in Photoshop
    - expand canvas to a size that covers the whole image circle of the lens (using the maximum shift you want to use)
    - move your image in the expanded canvas until the optical centre of the lens is in the middle (you can create actions in PS to do those tasks)
    - save to lightroom
    - then you need a custom made profile for the Pentax lens with your expanded canvas to apply it to that image in LR. Then crop back to the original image size.
    - this profile can be made using adobe lens profile creator.
    - but for that you need at least nine images of a test target with different amounts of shift in different direction.
    - every image must be expanded to the canvas size that covers the whole image circle of the lens
    - very time consuming process

    So would the sharpness of the lens in comparison to other options be worth all that work? I am not sure. The shifted Contax 645 35mm lens can easily be corrected with provided profiles in C1 and the Alpa plugin. This is an advantage of the Contax. Its disadvantage is that you can only use it with fixed aperture if you want to shift.

    As was mentioned by others: cropping the TS-E 24mm is an option too. Would be interesting to see a comparison between these 3 options.

    Best - Marc
    You left me behind with the step, "open in Photoshop" Seriously, that sounds like a lot of work. Were I shooting architecture and interiors for clients, I'd be looking for a better lens.

    I should emphasize, I do not know if the optical adjustments made to the HD version corrected the mustache distortion problem. If I knew someone who had one it would be easy to check on my setup. Alas, I don't.

    Good luck, Rob

  30. #30
    Member
    Join Date
    Dec 2014
    Posts
    57
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by rdeloe View Post
    You left me behind with the step, "open in Photoshop" Seriously, that sounds like a lot of work. Were I shooting architecture and interiors for clients, I'd be looking for a better lens.

    I should emphasize, I do not know if the optical adjustments made to the HD version corrected the mustache distortion problem. If I knew someone who had one it would be easy to check on my setup. Alas, I don't.

    Good luck, Rob
    yes, I did that once. Was not worth it.
    So I now know that the Pentax wont be for me.

  31. #31
    Member
    Join Date
    Jun 2015
    Posts
    39
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by rdeloe View Post
    You left me behind with the step, "open in Photoshop" Seriously, that sounds like a lot of work. Were I shooting architecture and interiors for clients, I'd be looking for a better lens.

    I should emphasize, I do not know if the optical adjustments made to the HD version corrected the mustache distortion problem. If I knew someone who had one it would be easy to check on my setup. Alas, I don't.

    Good luck, Rob
    This is the flaw with the lens, there's too much distortion when shifted to use it for commercial architecture and interiors but as Fuji haven't produced their own we're stuck with it.

    In Capture One you can use the Contax 645 35mm profile and get decent results, and using the 'Movement' tab you can type in shift correction. It's certainly much better with shift in landscape orientation rather than portrait. Also, the slight field curvature in the FA lens is quite useful for interiors where depth of field is a main priority.

  32. #32
    Super Duper
    Senior Member

    Join Date
    Mar 2009
    Posts
    4,130
    Post Thanks / Like
    Images
    1

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by Owen View Post
    This is the flaw with the lens, there's too much distortion when shifted to use it for commercial architecture and interiors but as Fuji haven't produced their own we're stuck with it.

    In Capture One you can use the Contax 645 35mm profile and get decent results, and using the 'Movement' tab you can type in shift correction. It's certainly much better with shift in landscape orientation rather than portrait. Also, the slight field curvature in the FA lens is quite useful for interiors where depth of field is a main priority.
    In my experience, the field curvature seen in the FA lens is proportional to camera to subject distance. At close range its relative small. At mid distance its noticeable but at near infinity for landscapes, it's extremely large. So much so, that at infinity and regardless of the f-stop (assuming the lens/camera adjustment shows no front or back focus), its nearly impossible to get edges side of the frame "sharp". Between myself and another forum member, we tried dozens of samples. One partial work around was to set the lens to backfocus at infinity to the point where the center of the frame still retained an acceptable degree of sharpness, but pushed the focus of the sides and edges of the frame "rearward", so that the sides and edges had at least a relative degree of being somewhat in-focus but even at that, softness at higher magnification was clearly evident.

    Therefore how acceptable this field curvature is depends of camera to subject distance with the FA lens and of course subject matter.

    Dave (D&A)
    Last edited by D&A; 24th May 2020 at 01:04.

  33. #33
    Member
    Join Date
    Jul 2019
    Posts
    146
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by D&A View Post
    In my experience, the field curvature seen in the FA lens is proportional to camera to subject distance. At close range its relative small. At mid distance its noticeable but at near infinity for landscapes, it's extremely large. So much so, that at infinity and regardless of the f-stop (assuming the lens/camera adjustment shows no front or back focus), its nearly impossible to get edges side of the frame "sharp". Between myself and another forum member, we tried dozens of samples. One partial work around was to set the lens to backfocus at infinity to the point where the center of the frame still retained an acceptable degree of sharpness, but pushed the focus of the sides and edges of the frame "rearward", so that the sides and edges had at least a relative degree of being somewhat in-focus but even at that, softness at higher magnification was clearly evident.

    Therefore how acceptable this field curvature is depends of camera to subject distance with the FA lens and of course subject matter.

    Dave (D&A)
    In my side-by-side comparison of an FA and an A at infinity, I saw the same phenomenon you're describing Dave. That's why I kept the A. I'm sure I'd feel differently about it were I shooting primarily architecture, but for what I do it's a very fine optic that serves me well.

  34. #34
    Senior Member Ed Hurst's Avatar
    Join Date
    Sep 2008
    Location
    Sydney
    Posts
    1,547
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    I strongly suspect that the Pentax DFA would be the answer to this - it does seem to have corrected most of the problems in the earlier versions. But I don't have one to test, sadly. I do know one or two people who do though...

  35. #35
    Member
    Join Date
    Apr 2014
    Posts
    172
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Am also in this market, I currently have the Canon 24mm TS-E II, Pentax 645 35mm A and the Hasselblad 50mm FLE.

    Just saw this on Ebay when searching for the price of a Contax 645 35mm.


    https://www.ebay.com.au/itm/264680715261?ul_noapp=true

    and

    https://www.facebook.com/kimca1977/


    I contacted the guy and asked about the aperture, considering it is controlled electronically and this was his reply....

    "Hello,

    Thanks for your interest.

    We have modified the iris to allow manual operation.

    Question always welcome.

    Best regards,
    Kim"


    Also asked about whether it would be cheaper without modifying to PL mount and this was his reply

    " Maintaining the mount does not affect the cost of the operation.

    This is because all parts of the lens have to be replaced by changing the aperture manually and rebuilding the housing. "

    I also asked about whether it can be changed to an Eos mount and he replied

    " It can be changed.

    Since the mount side has been modified by PL work, it can be changed without problems. "





    Very steep price but I can imagine how much work goes into it. Cannot quite remember what the Cambo conversion for the Actus is but I think it was over $1000 US and that is potentially less work..

    https://www.cambousa.com/distagon-35...or-cambo-actus


    I wonder if any extra vignetting is introduced by this mod, when using it for the purpose of a "Shift" lens?

  36. #36
    New Member
    Join Date
    Aug 2014
    Location
    Kampen
    Posts
    17
    Post Thanks / Like

    Re: best 35mm shift option : Pentax 645 HD DFA VS Contax 35 PC distagon for GFX 50r?

    Quote Originally Posted by wallpaperviking View Post
    Am also in this market, I currently have the Canon 24mm TS-E II, Pentax 645 35mm A and the Hasselblad 50mm FLE.

    Just saw this on Ebay when searching for the price of a Contax 645 35mm.


    https://www.ebay.com.au/itm/264680715261?ul_noapp=true

    and

    https://www.facebook.com/kimca1977/


    I contacted the guy and asked about the aperture, considering it is controlled electronically and this was his reply....

    "Hello,

    Thanks for your interest.

    We have modified the iris to allow manual operation.

    Question always welcome.

    Best regards,
    Kim"


    Also asked about whether it would be cheaper without modifying to PL mount and this was his reply

    " Maintaining the mount does not affect the cost of the operation.

    This is because all parts of the lens have to be replaced by changing the aperture manually and rebuilding the housing. "

    I also asked about whether it can be changed to an Eos mount and he replied

    " It can be changed.

    Since the mount side has been modified by PL work, it can be changed without problems. "





    Very steep price but I can imagine how much work goes into it. Cannot quite remember what the Cambo conversion for the Actus is but I think it was over $1000 US and that is potentially less work..

    https://www.cambousa.com/distagon-35...or-cambo-actus


    I wonder if any extra vignetting is introduced by this mod, when using it for the purpose of a "Shift" lens?
    A PL mount or the way we do it, both ways require a mechanical aperture but have different purposes. We prefer to get rid of the mount, as it gives better use of the lens' image circle. For cinema use that's obviously not an issue.
    Cambo Photographic Industry BV - www.cambo.com

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •