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

archivue

Active member
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 ?
 

rdeloe

Well-known member
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=193V-N_EJE9DIBfrEdGWcfXD3pMI_9exE
 

D&A

Well-known member
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)
 
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rdeloe

Well-known member
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


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)
 

D&A

Well-known member
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)
 
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archivue

Active member
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 !
 

tsjanik

Well-known member
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
 

rdeloe

Well-known member
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.
 

archivue

Active member
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 ?
 

Audii-Dudii

Active member
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...
 

chrismuc

Member
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.
2048_DSF9658.jpg2048_DSF9658_crop.jpg2048_DSF9763c.jpg2048_DSF9763c_crop.jpg
 

Attachments

Audii-Dudii

Active member
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>
 

MGrayson

Subscriber and Workshop Member
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
 

chrismuc

Member
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.html?origterm=kipon+contax+645+shift+adapter&searchredirect=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.
 

marc aurel

Active member
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
 

rdeloe

Well-known member
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/lensreviews/hd-pentax-d-fa-645-35mm-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
 

marc aurel

Active member
Marc,

1. Yes, the one you named is the latest one: https://www.pentaxforums.com/lensreviews/hd-pentax-d-fa-645-35mm-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
 
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