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Q: Contax 645/Aptus 12/Arca Rm3di

chrismuc

Member
After squeezing out the max from my 5D2 with the TSE 17 and 24 II lenses for architectural work and (mainly) Zeiss and Leica lenses for other kind of work I am about to upgrade to digital medium format. That's a big step with many possibilities, combinations that work and that don't, partly unclear future perspectives of systems, models and brands, so I have a few questions to you experienced guys who went this way for quite a time.

After evaluating the possibilities, my plan is to get a Contax 645 for handhold AF work and product photography and an Arca Swiss Rm3di for architecture work (plus Leaf Aptus-II 12).

Why Contax 645?

+ not too expensive and rather big choice of cam, lenses and accessory on second hand market
+ I just love Zeiss lenses:)
+ particularely the Zeiss Contax 645 120f4 Apo-Macro :))
+ possibility to use (Zeiss:) Hasselblad lenses via adapter
- "dead" system (astonishing how alive a dead system can be)
- not all Contax 645 lenses good enough for 80 MP back (?)
- no 28mm lens available :-(

Why Arca Swiss Rm3di

+ modular system and mechanical quality is convincing (+ Alpa)
+ open system regarding lenses and backs (- Sinar arTec)
+ back is shifting up/down/left/right for shift and for stich (that's a +++ for me, don't know any other tech cam to offer this feature)
- no sliding back (only from Kapture, I would prefer the integrated Sinar and Hartblei solution due to higher precision)
- no website (that's just silly, I don't even know where to get the cam in Germany, I might have to travel to France ... which is actually no drawback, cause I love France;-)

Why Leaf Aptus-II 12

+ full frame 645 54x40mm (++)
+ resolution
+ file quality (from what I have seen up to now)
+ no micro lenses
+ (screen size)
- long exposure noise (?)
- camera adapter not exchangable (I would have to stick to Contax, which is a risk because the back is the highest investment of the whole set-up)

My questions:

1 Hasselblad mounts
Is Hasselblad C, CF, CFE, F, FE the same bajonet mount? Meaning which lenses would fit via adapter to the Contax 645 cam body?

2 Contax 645 lenses
I assume that the Contax 645 35f3.5, 55f3.5 and 120f4 Apo-Macro lenses are "sharp" enough to make real use of the 80 MP / 5.4 micron Leaf back. Is that so?
Is the corner sharpness of the Contax 645 35 and 55 wide angle lenses on a 54x40mm back comparable good to the best Schneider/Rodenstock lenses in that focal range?
Did anyone use the Contax 645 80f2, 140f2.8, 210f4, 350f4 lenses with a high resolution full frame back like the Leaf Aptus-II 10 or PhaseOne 65+? Is such a combination qualitywise satisfying?

3 Schneider/Rodenstock lenses
Regarding the (wide angle) lenses for the tech cam I am not sure to go the way of Schneider symmetrical lenses or of Rodenstock retrofocus lenses (models with 90mm+ image circle in order to allow extensive shift movements).

Schneider symmetrical
+ corner sharpness shiftet mayby slightly better
+ less distortion, no mustache distortion
+ 28mm lens with 90mm image circle available

Rodenstock retrofocus
+ less/no magenta/cyan color cast towards edges (?)

So my questions:
Is corner sharpness shiftet better with Schneider XL 28/35/43/47mm lenses or with Rodenstock W 32/40/50mm lenses?
Do the Rodenstock lenses show any color cast towards the edges and do the Schneider lenses show strong cast?
Does the Leaf 12 back without microlenses perform better in this respect than the PhaseOne 65+?
How well does the Leaf software compensate such color cast (I think I read somewher that it does)?

(I did not recognize any color cast problem with the Canon 17 and 24 TS-E or with the Zeiss CY 21 on a 5D2 with micro lenses and the 17 with full shift means an angle of view like a 10.5mm lens, so that's pretty amazing. On the other side the Zeiss ZE 21 shows a cast and all symmetrical design wide angle lenses on a Leica M8/M9 with their very short distance from the back lens to the sensor and the steep out of axis angle of light produce strong casts towards the sensor edges. So I am wondering how serious this problem is with the mentioned MF lens - sensor combinations.)

4 Rodenstock mustache distortion
The mustache distortion of the Rodenstock lenses is not so easy to adjust in post, especially if the lens is used with shift.
As far as I know, Alpa and Sinar do offer software to compensate such, but Arca Swiss doesn't. Any other software with lens profiles available? Or Leaf/Capture One?
(Otherwise I would generate my own profile for Kekus lensfix PS plugin, like I did for example for the Zeiss CY 35f2.8 PC shift lens for the 5D2.)

5 Leaf raw files
Is it possible to open Leaf raw files directly in PS or is it possible to convert them first to DNG and then open them in PS because my workflow is (up to now) PS based?

6 Long exposures
How is the quality of the Leaf 10/12 files at ISO 80 and 160/200 at 15 sec. and 30 sec.? Still "very fine" or some long exposure artifacts?

7 iPad
I read that one might connect an iPad to a Leaf back and will get an "after view" or "live view" pic. How are iPad and back connected? Via WLAN or cable or bluetooth?

8 Back sliding
I am wondering that only Arca Swiss is offering the possibility to shift the back horizontally and vertically because this allow perfect shifting AND stiching while moving the lens side only is usable for shifting but not for parallax-free stiching. Is there any drawback of doing all shift movements (no tilt required) on the back side?

9 Cropping and focussing
Of course it is a major drawback that the MF backs still are CCD which does not allow live view. So the question is how to best crop and focus the motive? An optical viewer is too unprecise for cropping, does not help for shift movements and does not allow focussing. I like most the idea of having an integrated sliding back for back and ground glass (+ lupe) for quick and precise focussing. But to my knowledge this opportunity is only offered by a few tech cam manufacturers (Sinar, Hartblei, Gottschalt). So for cropping one needs to use a ground glass, I assume. But changing forth and back from ground glass to the back all the time seems very uncomfortable to me and will cause dust on lens back and sensor frequently. For focussing with wide angle lenses I think it's most convenient to use the hyperfocal distance for a given motive distance and aperture, for longer focal lengthes one might have to digitally measure the distance and work with trial and error.
In this matter your experience would be greatly appreciated.

10 Aperture and circle of confusion
According to optical physics, the circle of confusion in micron is roughly the value of the aperture. This means that at f 5.6 the circle of confusion is roughly the pixel size of the Aptus-II 12 back of 5.4 micron. Using f8 might still be okay but any more closed aperture should result in confusion circles which are larger than the pixel size and therefore it seems to be impossible to make use of the full sensor resolution at f11 and f16 or above. The lack of an AA-filter with the much higher sharpness per pixel compared to an AA-filter 135 FF cam compensates this a bit but still I am wondering that many photographers successfully use f16 or even smaller. So, which f-stop is really useful at high resolution backs like Aptus-II 10 and 12 or PhaseOne and 65+?

Sorry for taking so much of your time with such a long post!
Thanks in advance for your help and advice

Christoph
 

thomas

New member
+ back is shifting up/down/left/right for shift and for stich (that's a +++ for me, don't know any other tech cam to offer this feature)
Horseman SW-D II Pro, Cambo WRS, Alpa Max (with adapter) also provide 4 way shift on the rear.

- no sliding back (only from Kapture, I would prefer the integrated Sinar and Hartblei solution due to higher precision)
there is also Arca's rotaslide.

- no website (that's just silly, I don't even know where to get the cam in Germany, I might have to travel to France ... which is actually no drawback, cause I love France;-)
talk to Mr. Pfisterer: arca-shop.de

Aptus-II 12
- camera adapter not exchangable (I would have to stick to Contax, which is a risk because the back is the highest investment of the whole set-up)
Leaf offers a mount swap option (for a reasonable price).

2 Contax 645 lenses
I assume that the Contax 645 35f3.5, 55f3.5 and 120f4 Apo-Macro lenses are "sharp" enough to make real use of the 80 MP / 5.4 micron Leaf back. Is that so?
I don't know the 55mm but the 35m and the 120mm are great lenses. I guess they will work beautifully in conjunction with the Apt.12.

Is the corner sharpness of the Contax 645 35 and 55 wide angle lenses on a 54x40mm back comparable good to the best Schneider/Rodenstock lenses in that focal range?
no. The 35mm is really an impressive lens (beside distortion) ... but the Digarons and Digitars are simply better.

Do the Rodenstock lenses show any color cast towards the edges and do the Schneider lenses show strong cast?
Does the Leaf 12 back without microlenses perform better in this respect than the PhaseOne 65+?
How well does the Leaf software compensate such color cast (I think I read somewher that it does)?
all these lenses show color cast. Though some show more color cast and some show less you will always shoot a "white reference" ("Lens Cast Calibration") anyway. The correction of color cast is actually a non-issue as all the MFD sofwares provide dedicated tools.
As to the lenses. The Digarons are generally faster than the Digitars. Too, for large movements with the Digitars you should use a glass centerfilter. The Digitars generally show less distortion.

The mustache distortion of the Rodenstock lenses is not so easy to adjust in post, especially if the lens is used with shift.
As far as I know, Alpa and Sinar do offer software to compensate such, but Arca Swiss doesn't.
The Alpa Lens corrector is for free! It corrects not only digital large format lenses, but also Contax 645 (and many other) lenses.

Is it possible to open Leaf raw files directly in PS or is it possible to convert them first to DNG and then open them in PS because my workflow is (up to now) PS based?
AFAIK, yes. Capture One also supports Leaf files.
When you are working with the tech camera you won't use PS ... as it doesn't provide a dedicated tool to correct cast cast.

changing forth and back from ground glass to the back all the time seems very uncomfortable to me and will cause dust on lens back and sensor frequently.
it is uncomfortable, yes. As to dust... it depends on the conditions. I change groundglass and back all the time but dust hasn't been an issue for me by now. But I guess it would be an issue in areas with high humidity (or so).

For focussing with wide angle lenses I think it's most convenient to use the hyperfocal distance for a given motive distance and aperture, for longer focal lengthes one might have to digitally measure the distance and work with trial and error.
http://forum.getdpi.com/forum/showthread.php?t=17485
http://forum.getdpi.com/forum/showthread.php?t=19369

it seems to be impossible to make use of the full sensor resolution at f11 and f16 or above.
although most lenses will produce best results at f5.6 and f8 you still can use f11 (excellent) and f16 (still very good). Depends on the actual lens, of course. Smaller apertures than f16 will be an issue.
 
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chrismuc

Member
> Many thx Thomas for the quick, detailed and very profound answer and help!

Horseman SW-D II Pro, Cambo WRS, Alpa Max (with adapter) also provide 4 way shift on the rear.

> thx, good to know

there is also Arca's rotaslide.

> yesss, now I see

talk to Mr. Pfisterer: arca-shop.de

> ok, i thought arca-shop is an American Arca Swiss dealer
> but great, it's actually German:)

Leaf offers a mount swap option (for a reasonable price).

> very good. a German Leaf dealer denied that this is possible

I don't know the 55mm but the 35m and the 120mm are great lenses. I guess they will work beautifully in conjunction with the Apt.12.
The 35mm is really an impressive lens (beside distortion) ... but the Digarons and Digitars are simply better.

> ... I thought so :) :-(

all these lenses show color cast. Though some show more color cast and some show less you will always shoot a "white reference" ("Lens Cast Calibration") anyway. The correction of color cast is actually a non-issue as all the MFD softwares provide dedicated tools.

> good!!

The Alpa Lens corrector is for free! It corrects not only digital large format lenses, but also Contax 645 (and many other) lenses.

> thx very good

it is uncomfortable, yes. As to dust... it depends on the conditions. I change groundglass and back all the time but dust hasn't been an issue for me by now. But I guess it would be an issue in areas with high humidity (or so).

> hmm I work a lot in south China which is sub-tropical, but let's see ...
> anyhow I will test the Rotaslide

although most lenses will produce best results at f5.6 and f8 you still can use f11 (excellent) and f16 (still very good). Depends on the actual lens, of course. Smaller apertures than f16 will be an issue.[/QUOTE]

> this was my experience too from 5D2 w/ AA-filter and
> R8+DMR w/o AA-filter (both 6.4 micron pixel size)

> thx again Thomas!
 

Christopher

Active member
Well I can give you some feedback on some aspects. I currently have a P65 and know a lot about the arca System.

- I think the Leaf back is very nice. Just not really a step forward when coming from a P65. Ill have to see with what changes phase one comes up in the next few months. (hopefully)

Let's talk about the Arca

Thomas did a great job answering most questions so I will only add a few things.

Walter Pfisterer from Arca-Shop really knows the whole system. I also know that he sells hid demo Arca Rm3d for around 2999EUR, which is a nice discount if one doesn't need the new 'i' features.

Sliding back, is nice but I'm not sure if I really would need it.

Lenses:

I can tell you that the Rodenstock HR90, is probably the best lens I have ever used.
Rodenstock 40 vs Schneider 43: I will have both lenses very soon and will try both on the same camera. In theroy the Schneider should be better for stitching. (larger image circle) I will write a small review once I have both lenses here
Schneider 28 vs Rodenstock 32: Both are probably great lenses, I just bought the 32, because it was actually shipping. The best date I got for a 28 was February next year.
I can give you more feedback on the 32 when I have it here. The 28 is around 1100EURs cheaper, however if one needs a glass center filter the price might be closer together.

Alpa lens correcter works great with Schneider and Rodenstock so I don't really care much about lens distortion. I find stuff like, sharpness and light fall off much more important.

If you have any more questions just ask.

greetings from Munich
 

thomas

New member
Leaf offers a mount swap option (for a reasonable price).
> very good. a German Leaf dealer denied that this is possible
Yair Shahar is Product Manager of Leaf and very active on this board (username: "yaya"). Maybe he can clarify further.
I was told there is a mount swap... so maybe also talk to another dealer.

The 35mm is really an impressive lens (beside distortion) ... but the Digarons and Digitars are simply better.
> ... I thought so :) :-(
I guess you will hardly find a better 35mm 645 lens - the Distagon 3.5/35 is extremely sharp in the center, stopped down also very sharp at the edges, it provides high contrast and very nice color rendition ... however the Digarons & Digitars are still one step better.

hmm I work a lot in south China which is sub-tropical
I think under these conditions a sliding back is almost mandatory. If you also work on cranes or lifting platforms (or so) I think you definitely should use a camera with sliding back. So it all boils down more or less to the Rm3D/i or the Sinar arTec (or Gottschalt) - but there is no Contax mount for the arTec and it's also not compatible with Digitar lenses.
 

thomas

New member

chrismuc

Member
Thx again for your answers!
@ Christopher
Hallo Christopher, ich bin übrigens auch Münchner:)
Will return from Guangzhou this sunday for two weeks in Munich. Then again China.
Would be nice to stay in touch.
Btw very nice works on ur site.
[email protected]
occhio.com
 

BradleyGibson

New member
1 Hasselblad mounts
Is Hasselblad C, CF, CFE, F, FE the same bajonet mount? Meaning which lenses would fit via adapter to the Contax 645 cam body?

[bg] All of the above share the same bayonet mount and will fit your Hasselblad->Contax 645 adapter. Stop-down metering/shooting, of course.

2 Contax 645 lenses
I assume that the Contax 645 35f3.5, 55f3.5 and 120f4 Apo-Macro lenses are "sharp" enough to make real use of the 80 MP / 5.4 micron Leaf back. Is that so?

[bg] Should be fine. These are very good optics.

Is the corner sharpness of the Contax 645 35 and 55 wide angle lenses on a 54x40mm back comparable good to the best Schneider/Rodenstock lenses in that focal range?

[bg] They're not *that* good! ;) You'll see a difference between the Zeiss' and the best Schneiders/Rodenstocks.

Did anyone use the Contax 645 80f2, 140f2.8, 210f4, 350f4 lenses with a high resolution full frame back like the Leaf Aptus-II 10 or PhaseOne 65+? Is such a combination qualitywise satisfying?

[bg] Only used it with a P45+; but the as far as IQ is concerned, results were very satisfying. If memory serves the 210 was weaker than the others. I eventually sold the system though because of the vibrations I was getting from the focal plane shutter at high magnifications. The Tele-ApoTessar is spectacular, but was quite difficult to use successfully because of this issue. There is a thread here on GetDPI where I discussed the problems with sample images.

5 Leaf raw files
Is it possible to open Leaf raw files directly in PS or is it possible to convert them first to DNG and then open them in PS because my workflow is (up to now) PS based?

[bg] I've been trying to get Yair to put this suggestion in for a future Aptus firmware release--he has not responded yet as to whether he will do this, so at the moment we must go through an intermediate conversion step to get uncompressed .mos files.

6 Long exposures
How is the quality of the Leaf 10/12 files at ISO 80 and 160/200 at 15 sec. and 30 sec.? Still "very fine" or some long exposure artifacts?

[bg] I did my first outdoor test shoot yesterday. Here is a link to an uncompressed Leaf AFi-II 10 raw file + (+.xmp for dust spot removal) that is usable in the latest versions of ACR/LR. It is an exposure of 13s, the longest I've done so far.

7 iPad
I read that one might connect an iPad to a Leaf back and will get an "after view" or "live view" pic. How are iPad and back connected? Via WLAN or cable or bluetooth?

[bg] No idea yet. The bottom of the back carries the bluetooth logo but I don't know how the connectivity options work yet. My understanding is you have to be shooting tethered to a PC, and the iPad/iPhone picks up what it needs via WiFi. Perhaps the bluetooth is simply used as a trigger?

10 Aperture and circle of confusion
According to optical physics, the circle of confusion in micron is roughly the value of the aperture. This means that at f 5.6 the circle of confusion is roughly the pixel size of the Aptus-II 12 back of 5.4 micron. Using f8 might still be okay but any more closed aperture should result in confusion circles which are larger than the pixel size and therefore it seems to be impossible to make use of the full sensor resolution at f11 and f16 or above. The lack of an AA-filter with the much higher sharpness per pixel compared to an AA-filter 135 FF cam compensates this a bit but still I am wondering that many photographers successfully use f16 or even smaller. So, which f-stop is really useful at high resolution backs like Aptus-II 10 and 12 or PhaseOne and 65+?

[bg] I've attached a high quality JPEG (Q=10) screenshot of 100% view side-by-side of an f/16 and an f/22 long exposure (13s & 8s respectively). The f/22 was underexposed, so you are looking at Exposure = +1.4 and Contrast = 0 (ie. -25 from default) to get them to match approximately.

As you can see, individual stadium seats are clearly visible, but the f/16 shot is that much better defined. Although this was taken with an 80mm lens, none of this is visible to the naked eye, of course, the stadium is very far away. Individual windows on houses in West Seattle can be seen through the girder scaffolding of the stadium. Those houses are many miles away.


Sorry for taking so much of your time with such a long post!
Thanks in advance for your help and advice

Christoph

[bg] No worries Christoph, this information is so difficult to come by. I hope this helps.
-Brad
 

jps

New member
Hello Bradley

The 13sec mos file is very interesting. Can I ask how the white balance was set?

Cheers JOHN
 

BradleyGibson

New member
I used a custom WB (touched a location on-screen) in a previous frame. As the sun rose, the light was changing by the minute. I found the bluish tint kept the sense of night to go along with the long exposure.
 

BradleyGibson

New member
I just now saw that my screenshot is downsized pretty severely; I'll upload a full-resolution .png to the same folder as the raw.
 

jps

New member
Brad

Yes , I think the wb looks good, was just curious as to how you got it.

I have just ordered a 12 back in afi mount to go with my hy6 and artec.
Dont really know much about the leaf workflow - does the back have any wb presets or is it all manual balance? I am hopping to continue using LR for ease of library management plus export to leaf/c1 images that need special treatment. Does that make sense to you?

Cheers JOHN
 

BradleyGibson

New member
I think the Leaf has the best WB user experience in the business. (I've owned Phase, Sinar and Hasselblad backs as well.) With the touch screen, you touch whatever part of the picture you want the back to neutralize, and it'll show you the image with that gray balance. Press 'OK' and that custom WB is set for that photo plus all subsequent photos.

Of course there are the standard daylight/tungsten, etc. presets. I haven't found a °K setting, but I do prefer the touch-the-picture method. A couple of times this AM there wasn't anything neutral in the picture, so in these circumstances a °K would be nice...

Other than that, my only complaint with the back is it ONLY lets you write compressed raw files, and only Leaf/Phase software reads compressed raws. So there's an extra step converting the compressed raws to uncompressed raws so other utilities like Photoshop/ACR, Lightroom or even the Mac OS can read them. *sigh*

Yes, your workflow makes sense. Leaf Capture gives the best out-of-the-box color, IMHO. LR's default colors are still atrocious. :) Still, color is arbitrary (within reason), so it doesn't take much to tame it.

I hope you'll post some samples from the -II 12 when you get it; I'm interested in it as well--the 4:3 ratio means I'll waste fewer pixels when I shoot square--60MP square? Oh yeah, baby...

All the best,
-Brad
 

yaya

Active member
Christoph,

I'll be in Germany (Stuttgart/ Munich) next Thursday-Friday (11-12 Nov). Feel free to contact me offnline and maybe we can arrange to meet. I'll have the Aptus-II 12 and a bunch of raw images I can show you and will be happy to discuss all your queries.

One note regarding lens cast correction; Leaf Capture allows you to correct your raw file and then to save it as a corrected raw, which can then be taken into LR/ ACR or archived etc. You can also choose to remove light falloff at the same time if you want to.

Small note for Brad as this might ease your pain a bit (for the time being). The Leaf Raw converter lets you save compressed files that are compatible with LR so it saves some space on your HD, server etc.

Yair
 

BradleyGibson

New member
Hi, Yair,

I've been using the Leaf Raw Converter to uncompress the raws, but if I tick the "Save compressed (lossless)" box, the raws will be re-compressed into a format compatible with 3rd party tools?

Thank you for the tip! I hadn't realized that.

Can you share what's going on? Are the backs writing a new variant of the .MOS file format or something?

A suggestion for a future version of Leaf Raw Converter--make the folder boxes and settings sticky (they remember how they were last used), as I'm sure many of us frequently import from and copy to the same places.
 
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jps

New member
Hi Bradley

Thanks for the info. I certainly will post some images when I get it. Leaf say end of 1st quarter 2011 - in the meantime they are lending me a 10 back to play with - am keen to get it and start familiarising myself with the workflow. WB does sound good. I know what you mean about LR colour , however I use the DNG editor to make profiles/recipes - it produces excellent results IMHO . Have you tried any wide lenses with the back? I notice that Leaf say their design is much less prone to colour casts.

Cheers JOHN
 

BradleyGibson

New member
Hey, John,

Great! I asked for the same arrangement (buy a -II 12 now and get a -II 10 as an interim loaner, but was told the "-II 12's launch is too soon" (not sure why that would have a bearing, and even if it did, wouldn't less time with the loaner be better?). Anyway, I'm glad you're hooked up and ready to roll!

The widest I've used on the -II 10 is the AFD 50mm. It was defective, unfortunately and I had to return it. Ideally I'd like to test it against a monochromatic, featureless wall at minimum focusing distance to see how uniform it is, but I did not get that opportunity. I'm still in the hunt for one, and know folks with Rollei glass as wide as 30 (fisheye). In fact, I'll be getting together with a Rollei buddy to do some shooting over a weekend. I'll get to see how the -II 10 does with his wide glass.

Yes, I plan to do the same--create my own profiles for color and for my lenses to get things dialed in. I'm glad to hear that someone has used it and found it to be effective.

I'll keep u posted! :)

Best regards,
-Brad
 
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jps

New member
Hi Brad

I didnt have to ask for a loaner - they offered ! Perhaps its because it wont be available in Australia till April? maybe you will get one sooner! I have seen some shots taken with a 28 Rodenstock on a 10 back that were NOT cast corrected and had no discernible colour cast - very impressive. I hope the 12 is just as good!
If you are interested in a new 50mm lens ,last week the Australian Sinar distributor told me about some VERY good prices on a range of lenses including the 50 . The lenses are in Switzerland - could be worth chasing up!

Cheers JOHN
 

chrismuc

Member
Hi Yair,
11./12.11. (European date writing,-) sounds cool to me to get to know the Aptus-II 12. I send you and email with my mobile.
Keep in touch,
Christoph
 
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