Cambo Actus G with Rodenstock 55mm f/4.5 APO Sironar Digital and Nikon Z. Very soft edges...??

[rdeloe]

Nice shots Steve! and thank you for the info.
This solution works good for you. But after looking a bit more into it, it looks like the movement will be quite limited with a 33x44mm sensor : about 7mm rise/fall, which is not much...
So I might give the Rodi 55mm a try in the end, hoping that I do not get the obvious color cast of Rob...

Vincent, if you read the brief interaction between me and Alkibiades, you'll see where the confusion around colour casts arose. Alkibiades is saying you will get the colour cast with the Rodenstock 55 (as I did), but it's correctible. We all have different thresholds it seems. My threshold for colour cast is "Not visible -- nothing to correct". In contrast, Alkibiades' threshold seems to be "Can be corrected without damaging the image". It comes down to whether you think making LCC frames is a normal and unavoidable part of the workflow. If you're coming from the medium format back world, you'd consider it normal. I've only ever used mirrorless bodies, so for me it's normal -- which is why my threshold is where it is.

Anyway, one reason I like participating in these forums is I'm always learning things. Alkibiades suggest that one should use an LCC frame all the time with symmetrical lenses. I didn't think that was necessary, but I always like to check things empirically for myself rather than clinging to my assumptions. So yesterday I went for a little shoot in the snow with my Mamiya G 50/4, which is a symmetrical lens.

I made an LCC frame for every image, and in Lightroom I made with/without versions of each scene. Here's an image that used 9mm of rise at f/16. This is the correction frame. Note the light fall-off. I really can't see any colour shifts (which doesn't mean there aren't any!)




Here's the full image. On the left is the uncorrected version, and on the right is the version processed with Lightroom's Flat Field Correction tool using the LCC frame. Both are as imported, so no corrections for tone, temperature, etc.



Here's a 100% view of the top -- the region where I'd expect to see colour shifts. Again, on the left is uncorrected, and on the right is corrected using Flat Field Correction and the LCC frame. To my eye, there was no obvious magenta colour shift to correct (like what I saw on the Rodenstock 55). The Flat Field Correction tool also takes care of light falloff -- which it did here.



Here a 100% view of the top of the frame, this time using a gradient on both images where I brought highlights down considerably, and lowered exposure. Which blue sky is correct? That I cannot say. I find the blue of the sky in the uncorrected (left) version more pleasing, but it's not necessarily more accurate.



I should also mention that I shoot for black and white, and work almost exclusively in black and white, so you can see why I'm less fussed about colour faithfulness than other people! For this picture, I used the uncorrected RAF and darkened down the sky with a gradient (so any benefits from the Flat Field Correction fixing the light falloff would have been undone anyway).




So for what it's worth, I offer two conclusions:

1. The Mamiya G 50/4 is a very good lens. My current mounting approach only allows around 9mm of shift at this focus distance, but once I complete the conversion it should provide up to 15mm. Very preliminary testing suggests that the image quality will be plenty good at 15mm of shift, but that's to be confirmed.

2. I will not bother making LCC frames with this lens unless it's light falloff I want to correct. I'm simply not seeing any colour changes that need correction.

Best, Rob

 

[Alan]

Only marginally related to this thread, but it involves a symmetrical lens, shift-stitched on a Z7 with LCC correction...

Nikon Z7, Rodenstock 65mm f/4.5 Grandagon-N (4x5 lens), 3x3 shift-stitch on an Arca M2. LCC shot for each shift position, applied in C1 before stitching. No center filter used. I don’t remember aperture used, probably f/11. Lighting is not even - coming from window to left. There are a couple stitch/blend errors, but that wasn’t the focus of this test.


No LCC Correction


With LCC Correction

 

[vvince]

The Cambo 60mm Actar is relatively inexpensive and performs very well on the Actus.

Thanks for the info Scho, this might after all be the easiest solution. Cambo told me that due to its relatively small image circle, maximum shift will be 10mm, not much but could be just sufficient...

please read my expenasion correctly.
All Schneider/Rodenstock lenses- espacially wide- has Color cast. This is a fact. the one less the other more.
More wide- more color cast.
this is not an issue but a normal behavier of these lenses.
Therefor you should make always a standart LCC correction shot with the white milky board and remove the color cast in capture one or phocus.
even when you see no CCast you should do this.
This is not an issue but a normal work.
An issue become CC when the cast is too strong and the software cant remove it correctly.
This would happen on the 50 MP chip with schneider 24,28 and 35 xl lenses as also with roddy 4,5/35 and bigger movements with 4,5/45 mm ( not wit Roddy 4/35 mm HR that is a retrofocus-Digaron lens)
you see a too strong CCast when the color become dark magenta.
I hope it is clear now.
And also the 60 mm apo digitar as the xl 60 mm Digitar has color cast, very similar to the 55 mm, thay all are symetrical lenses.

Alkibiades,
Thanks for the info.
Which camera/digital back are you using if I may ask? Have you tested all those lenses or is it theoretical consideration from their specifications and design?

 

[vvince]

Vincent, if you read the brief interaction between me and Alkibiades, you'll see where the confusion around colour casts arose. Alkibiades is saying you will get the colour cast with the Rodenstock 55 (as I did), but it's correctible. We all have different thresholds it seems. My threshold for colour cast is "Not visible -- nothing to correct". In contrast, Alkibiades' threshold seems to be "Can be corrected without damaging the image". It comes down to whether you think making LCC frames is a normal and unavoidable part of the workflow. If you're coming from the medium format back world, you'd consider it normal. I've only ever used mirrorless bodies, so for me it's normal -- which is why my threshold is where it is.

Anyway, one reason I like participating in these forums is I'm always learning things. Alkibiades suggest that one should use an LCC frame all the time with symmetrical lenses. I didn't think that was necessary, but I always like to check things empirically for myself rather than clinging to my assumptions. So yesterday I went for a little shoot in the snow with my Mamiya G 50/4, which is a symmetrical lens.

I made an LCC frame for every image, and in Lightroom I made with/without versions of each scene. Here's an image that used 9mm of rise at f/16. This is the correction frame. Note the light fall-off. I really can't see any colour shifts (which doesn't mean there aren't any!)

View attachment 181634


Here's the full image. On the left is the uncorrected version, and on the right is the version processed with Lightroom's Flat Field Correction tool using the LCC frame. Both are as imported, so no corrections for tone, temperature, etc.

View attachment 181635

Here's a 100% view of the top -- the region where I'd expect to see colour shifts. Again, on the left is uncorrected, and on the right is corrected using Flat Field Correction and the LCC frame. To my eye, there was no obvious magenta colour shift to correct (like what I saw on the Rodenstock 55). The Flat Field Correction tool also takes care of light falloff -- which it did here.

View attachment 181636

Here a 100% view of the top of the frame, this time using a gradient on both images where I brought highlights down considerably, and lowered exposure. Which blue sky is correct? That I cannot say. I find the blue of the sky in the uncorrected (left) version more pleasing, but it's not necessarily more accurate.

View attachment 181638

I should also mention that I shoot for black and white, and work almost exclusively in black and white, so you can see why I'm less fussed about colour faithfulness than other people! For this picture, I used the uncorrected RAF and darkened down the sky with a gradient (so any benefits from the Flat Field Correction fixing the light falloff would have been undone anyway).

View attachment 181639


So for what it's worth, I offer two conclusions:

1. The Mamiya G 50/4 is a very good lens. My current mounting approach only allows around 9mm of shift at this focus distance, but once I complete the conversion it should provide up to 15mm. Very preliminary testing suggests that the image quality will be plenty good at 15mm of shift, but that's to be confirmed.

2. I will not bother making LCC frames with this lens unless it's light falloff I want to correct. I'm simply not seeing any colour changes that need correction.

Best, Rob

Nice test Rob,
I am actually very new to digital medium format. I have been shooting (and still shoot occasionally) large format 4x5 film (Iwith the following lenses : Nikkor SW 90mm f8, Grandagon N 90mm f4.5, Sironar S 150mm f5,6 and Sironar S 210mm f5.6, I might try to adapt them on the Actus+GFX50R), I still shoot medium format 6x7 film (Mamiya 7II), and I just moved from Canon 5DSR to the Fuji GFX50R, which I have been only using with native lenses up to now.
Until reading this thread I had never heard of LCC frames...
It looks like LCC correction is not a necessity for landscape, at least in many cases. In all honesty I find your first uncorrected shot the most pleasing ;-)
But I am planning to shoot architecture, urban environment, where color and brightness gradient would be more visible.
How do you actually shoot a LCC frame? I read a matte plate is necessary but I could not find where to find one...
Also, will the LCC correction only remove the gradient coming from the lens/sensor interraction, or will it remove also any natural gradient/inhomogeneity in the lighting of the scene?

Cheers
Vincent

 

[rdeloe]

Nice test Rob,
I am actually very new to digital medium format. I have been shooting (and still shoot occasionally) large format 4x5 film (Iwith the following lenses : Nikkor SW 90mm f8, Grandagon N 90mm f4.5, Sironar S 150mm f5,6 and Sironar S 210mm f5.6, I might try to adapt them on the Actus+GFX50R), I still shoot medium format 6x7 film (Mamiya 7II), and I just moved from Canon 5DSR to the Fuji GFX50R, which I have been only using with native lenses up to now.
Until reading this thread I had never heard of LCC frames...
It looks like LCC correction is not a necessity for landscape, at least in many cases. In all honesty I find your first uncorrected shot the most pleasing ;-)
But I am planning to shoot architecture, urban environment, where color and brightness gradient would be more visible.
How do you actually shoot a LCC frame? I read a matte plate is necessary but I could not find where to find one...
Also, will the LCC correction only remove the gradient coming from the lens/sensor interraction, or will it remove also any natural gradient/inhomogeneity in the lighting of the scene?

Cheers
Vincent

I come from large format too Vincent. Like you, I tried my large format lenses on my GFX 50R to see how they do. Most recently I was using Fujinon W lenses. I tested out the little Fujinon-W 125/5.6. It was absolutely usable starting at f/8. The colours were quite muted and low contrast, but otherwise fine. They're not going to be as sharp as the modern Fujinon GF lenses, but then again you can't shift the GF lenses!

Lens cast occurs because of issues related to how the sensor responds to light hitting it off-angle, which is what occurs when we're shifting lenses with shorter focal lengths. When it's a problem, it's a problem all the time. In other words, it's not something that happens in one kind of setting (like architecture) and not in another (like landscape). The reason I'm not seeing any with my Mamiya G 50/4 is because there isn't any to see. Look for that purple-magenta tint you're seeing on one side of my brick wall picture, and in Alan's example (above). It's usually matched with a greenish tint on the opposite side. You should not see any lens cast with the large format lenses you listed above. It tends to occur with focal lengths less than 60mm. This is why I'm so excited by my Mamiya G 50/4; I fully expected to see significant lens cast, and am delighted that I don't.

It's confusing because various names are used, e.g., lens cast, colour cast, and because software packages use different names for the correction function, e.g., in Lightroom it's called "Flat Field Correction", while in Capture One I believe they call it Lens Cast Correction (which is where LCC comes from).

To correct it, you shoot your picture, then you shoot an LCC frame. That first frame in my post above -- the featureless greyish image. Capture One has a short blog post with a picture showing someone shooting an LCC frame: https://support.captureone.com/hc/e...if-I-am-experiencing-problems-with-lens-cast- In a nutshell, you're shooting through a milky piece of plastic held flush to the front of the lens. This records overall illumination, illumination falloff (vignetting), and any lens cast that is occurring. "Correcting" this means running it through the software, which assumes that any darkening is light falloff, and any colour tint is lens cast. The software "subtracts" these from the image (I'm not explaining that correctly, but that will do!)

The distinction Alkibiades was making recognizes that sometimes you can't fix it because it's too strong. In the same way that "correcting" light falloff in Lightroom, Photoshop or Capture One involves increasing exposure in the darkened area -- with resulting damage to the image -- getting rid of very strong lens cast can ruin the image.

Note that lens cast is not a concern with SLR-type lenses. For example, my 35mm lens is the SMC Pentax-A 645 35/3.5. It does not suffer any lens cast concerns. It's the "symmetrical" lenses that use a simple lens design that have this problem. Your large format lenses are symmetrical; a "telephoto" large format lens is not symmetrical, but I don't see any in your list.

You can buy a nice set of pre-made LCC correction tools from Capture Integration. The price is very reasonable. I made one in the basement out of a piece of milky plexiglass. Cut to the size you want, and then use water and a very fine grit sandpaper to gently roughen the surface on both sides. If you've ever made your own ground glass for your large format camera, it's a similar procedure -- albeit using sandpaper instead of the grit you need for a proper ground glass.

Regarding the Cambo Actar 60, it's a nice ready-to-go solution. However, given that it's 60mm, f/4 and allows for 10mm of shift on a 33mm x 44mm sensor, I have a strong suspicion that's a Schneider Kreuznach Apo-Digitar 60/4 or its cousin the Apo-Componon HM 60/4 that's been rehoused and mounted for convenient use on an Actar. If I'm correct, then this is the lens I'm using on my GFX 50R (I have the Apo-Componon industrial mount version). It really is excellent. If you can't find the Actar, you could use one of these. They come in all kinds of mounts, from Copal 0 (for the Apo-Digitar variant) to 39mm x 1/26th inch screw thread enlarger mount size. It's all the same lens -- just different housing.

 

[vvince]

I come from large format too Vincent. Like you, I tried my large format lenses on my GFX 50R to see how they do. Most recently I was using Fujinon W lenses. I tested out the little Fujinon-W 125/5.6. It was absolutely usable starting at f/8. The colours were quite muted and low contrast, but otherwise fine. They're not going to be as sharp as the modern Fujinon GF lenses, but then again you can't shift the GF lenses!

Lens cast occurs because of issues related to how the sensor responds to light hitting it off-angle, which is what occurs when we're shifting lenses with shorter focal lengths. When it's a problem, it's a problem all the time. In other words, it's not something that happens in one kind of setting (like architecture) and not in another (like landscape). The reason I'm not seeing any with my Mamiya G 50/4 is because there isn't any to see. Look for that purple-magenta tint you're seeing on one side of my brick wall picture, and in Alan's example (above). It's usually matched with a greenish tint on the opposite side. You should not see any lens cast with the large format lenses you listed above. It tends to occur with focal lengths less than 60mm. This is why I'm so excited by my Mamiya G 50/4; I fully expected to see significant lens cast, and am delighted that I don't.

It's confusing because various names are used, e.g., lens cast, colour cast, and because software packages use different names for the correction function, e.g., in Lightroom it's called "Flat Field Correction", while in Capture One I believe they call it Lens Cast Correction (which is where LCC comes from).

To correct it, you shoot your picture, then you shoot an LCC frame. That first frame in my post above -- the featureless greyish image. Capture One has a short blog post with a picture showing someone shooting an LCC frame: https://support.captureone.com/hc/e...if-I-am-experiencing-problems-with-lens-cast- In a nutshell, you're shooting through a milky piece of plastic held flush to the front of the lens. This records overall illumination, illumination falloff (vignetting), and any lens cast that is occurring. "Correcting" this means running it through the software, which assumes that any darkening is light falloff, and any colour tint is lens cast. The software "subtracts" these from the image (I'm not explaining that correctly, but that will do!)

The distinction Alkibiades was making recognizes that sometimes you can't fix it because it's too strong. In the same way that "correcting" light falloff in Lightroom, Photoshop or Capture One involves increasing exposure in the darkened area -- with resulting damage to the image -- getting rid of very strong lens cast can ruin the image.

Note that lens cast is not a concern with SLR-type lenses. For example, my 35mm lens is the SMC Pentax-A 645 35/3.5. It does not suffer any lens cast concerns. It's the "symmetrical" lenses that use a simple lens design that have this problem. Your large format lenses are symmetrical; a "telephoto" large format lens is not symmetrical, but I don't see any in your list.

You can buy a nice set of pre-made LCC correction tools from Capture Integration. The price is very reasonable. I made one in the basement out of a piece of milky plexiglass. Cut to the size you want, and then use water and a very fine grit sandpaper to gently roughen the surface on both sides. If you've ever made your own ground glass for your large format camera, it's a similar procedure -- albeit using sandpaper instead of the grit you need for a proper ground glass.

Regarding the Cambo Actar 60, it's a nice ready-to-go solution. However, given that it's 60mm, f/4 and allows for 10mm of shift on a 33mm x 44mm sensor, I have a strong suspicion that's a Schneider Kreuznach Apo-Digitar 60/4 or its cousin the Apo-Componon HM 60/4 that's been rehoused and mounted for convenient use on an Actar. If I'm correct, then this is the lens I'm using on my GFX 50R (I have the Apo-Componon industrial mount version). It really is excellent. If you can't find the Actar, you could use one of these. They come in all kinds of mounts, from Copal 0 (for the Apo-Digitar variant) to 39mm x 1/26th inch screw thread enlarger mount size. It's all the same lens -- just different housing.

Thanks a lot for the info Rob, I feel ready to try LCC correction in a near future! I really appreciate you didactic dedication.
Regarding the Fuji lenses, I do not have any, but there is this promotional video where a a photographer is using a Fuji SWD 65mm f5.6 with the Fuji GFX.

Actually we do not see him using this lens, but he mentions using Fujinon lenses, and the video shows the 65mm, for what it's worth...
If you have this lens it might be worth checking it out.
As for me I finally ordered an Actar 60mm, we'll see... At least that will get me started.
When I find a reasonably priced Apo Sironar Digital 55mm I'll try it, for the larger image circle, hoping not to get the strong color cast you had...

Cheers
Vincent

 

[Alkibiades]

Thanks for the info Scho, this might after all be the easiest solution. Cambo told me that due to its relatively small image circle, maximum shift will be 10mm, not much but could be just sufficient...



Alkibiades,
Thanks for the info.
Which camera/digital back are you using if I may ask? Have you tested all those lenses or is it theoretical consideration from their specifications and design?

I am using and own a lot of camera set ups including the most Schneider and Rodenstock lenses, digital and analoge,
I use 3 Backs: Phase one 250 ( same 50 mp sensor as the Fuji 50-Hasseblad 50 mp), Leaf aptus12 with 80 MP and older Hasselblad H3D39 back.
My main set up is Cambo WRS with Digaron 23/32/40/50/90 and Schneider 43/47/60/150.
My second is Linhod Techno and Arca M-2 with Rodenstock Digaron 35mm,55 mm, 90, 180 mm and schneider 43,47,60,80,90,120,150 ,
and Arca Swiss RM3 with 43 xl schneider.
Color cast is not something that symetrical lenses have- all Rodenstocks Digarons- retrofocus lenses needs LCC correction!!!
For modern sony chips with 50 mp and the actuall 100 MP there is no other way if you want big movements and best resolution to use modern lenses that are done for such sensors.
So for this only schneider and rodenstock lenses will achieve the best results and LCC is necessery with all of them ( not with long lenses up 120 mm).
This is a fact.
The only one serious wide lens used in Middle format with high class is the schneider blue ring 35 mm- but without movements.
All other older middle format lenses from Pentax,mamiya, Contax ect.. that were made for film has older lens designs that cant resolve the modern chips. You can work with them- no problem- and even make great works ( photography is not only technic) but they cant give you that quality that these chips can achieve.
I still own Mamiya Z with 50-105-140 mm lenses but use tham for film only. I had the digital adapter for it but I found the quality OK but not great - with much older backs.
I also still own the contax zeiss 35 mm shift lens that is simply the same Contax 645 lens build in shift mechanism, becouse there is no modern 35 mm shift lens. I think it is the best old middle format lens, but even this lens should be updated for modern chips- no comparision to rodenstock lenses- 35 mm blows these lenses away.
I still own for fun 50 mm RZ and 50 mm shift 645 ( I would say it is the same optic.
But I would say thse optical design was totaly overwhelmedwith older and bigger 22 MP chips.
To use these lenses 15 years later with much smaller 33x44 chips with much higher pixel density will be even worse and not better.
I made some shots with mamiya 50 mm and 50 MP back for fun, but this lens cant match this sensor. Rodenstock 55 mm is in other league, even when the 60 xl or digaron 50 mm is sharper.
I find the modern Canon shift lenses 24II, 17, 50 mm-the best alternative to schneider-rodenstock lenses. Theay are modern designs with great performance and low prices.
Much better optical as older middle format lenses.

 

[rdeloe]

Here we have two pictures made with 50mm lenses, f/11, on a Fuji GFX 50R. The subject is 486m from the shooting position. Enlargement is 300%. Temperature was matched, but no other changes to the RAW file that was imported into Lightroom.

• Which one of these is the old medium format lens from the film days that can't possibly be any good on a 50 MP medium format digital sensor?
• Which one is the modern Fujifilm GF lens that was designed specifically for this 50 MP sensor, and which is considered one of the sharpest in the lineup at this focal length?

 

[Audii-Dudii]

I also still own the contax zeiss 35 mm shift lens that is simply the same Contax 645 lens build in shift mechanism, becouse there is no modern 35 mm shift lens.

FYI, even a quick look at the datasheets for these two lenses clearly shows this statement to be incorrect:

C645 35/f3.5 datasheet

C/Y 35/f2.8 PC datasheet

 

[vvince]

I am using and own a lot of camera set ups including the most Schneider and Rodenstock lenses, digital and analoge,
I use 3 Backs: Phase one 250 ( same 50 mp sensor as the Fuji 50-Hasseblad 50 mp), Leaf aptus12 with 80 MP and older Hasselblad H3D39 back.
My main set up is Cambo WRS with Digaron 23/32/40/50/90 and Schneider 43/47/60/150.
My second is Linhod Techno and Arca M-2 with Rodenstock Digaron 35mm,55 mm, 90, 180 mm and schneider 43,47,60,80,90,120,150 ,
and Arca Swiss RM3 with 43 xl schneider.
Color cast is not something that symetrical lenses have- all Rodenstocks Digarons- retrofocus lenses needs LCC correction!!!
For modern sony chips with 50 mp and the actuall 100 MP there is no other way if you want big movements and best resolution to use modern lenses that are done for such sensors.
So for this only schneider and rodenstock lenses will achieve the best results and LCC is necessery with all of them ( not with long lenses up 120 mm).
This is a fact.
The only one serious wide lens used in Middle format with high class is the schneider blue ring 35 mm- but without movements.
All other older middle format lenses from Pentax,mamiya, Contax ect.. that were made for film has older lens designs that cant resolve the modern chips. You can work with them- no problem- and even make great works ( photography is not only technic) but they cant give you that quality that these chips can achieve.
I still own Mamiya Z with 50-105-140 mm lenses but use tham for film only. I had the digital adapter for it but I found the quality OK but not great - with much older backs.
I also still own the contax zeiss 35 mm shift lens that is simply the same Contax 645 lens build in shift mechanism, becouse there is no modern 35 mm shift lens. I think it is the best old middle format lens, but even this lens should be updated for modern chips- no comparision to rodenstock lenses- 35 mm blows these lenses away.
I still own for fun 50 mm RZ and 50 mm shift 645 ( I would say it is the same optic.
But I would say thse optical design was totaly overwhelmedwith older and bigger 22 MP chips.
To use these lenses 15 years later with much smaller 33x44 chips with much higher pixel density will be even worse and not better.
I made some shots with mamiya 50 mm and 50 MP back for fun, but this lens cant match this sensor. Rodenstock 55 mm is in other league, even when the 60 xl or digaron 50 mm is sharper.
I find the modern Canon shift lenses 24II, 17, 50 mm-the best alternative to schneider-rodenstock lenses. Theay are modern designs with great performance and low prices.
Much better optical as older middle format lenses.

Thanks for the feedback and precision Alkibiades.
That's an impressive collection of lenses you've got!
I'll get a Rodenstock Apo Digital 55mm as soon as I find one in my budget.
Regarding your experience of the medium format lenses (especially Mamiya) vs large format lenses (Rodenstock, Schneider), it seems not so in line with that shared by Stevev and Rob in this thread. I have no experience with digital medium format (except with the Fuji GFX with the native GF lenses, which I find excellent, but there's no movement) so I can not comment on that.
Could it come from a different use, for example large shift values degrading the image quality on MF lenses more than on LF lenses?

Cheers
Vincent

 

[stevev]

Hi Vincent,

I've got some comparisons for you between the Mamiya M ULD 50mm f/4.5 and the Rodenstock 55mm Apo-Sironar digital f/4.5. I think they illustrate the lens cast you can expect and the comparative sharpness across the frame, including the edges.

I think they make my case but I'm going to reshoot them in the morning here in Brisbane, Australia because I want the lighting and framing exactly the same. Both the Rodenstock and the Mamiya were/are in genuine mint condition so they should be representative of what each lens can do. I'll start a new thread for the comparison and post the crops late tomorrow morning.

I can tell you ahead of time that they will be shot on the Actus G with a Nikon Z7 body, camera in landscape orientation; two rows of three images per row. The Actus seems to go a bit past 20 shift each side - about 22mm - so these images will reflect a virtual sensor about 80mm wide vs the Mamiya IC at 95mm and the Rodie at 125mm.

If you want anything specific, i.e. aperture etc. let me know, otherwise it will be f/11 and refocus each frame in the centre for each shot.

Cheers,
Steve.

 

[vvince]

Hi Vincent,

I've got some comparisons for you between the Mamiya M ULD 50mm f/4.5 and the Rodenstock 55mm Apo-Sironar digital f/4.5. I think they illustrate the lens cast you can expect and the comparative sharpness across the frame, including the edges.

I think they make my case but I'm going to reshoot them in the morning here in Brisbane, Australia because I want the lighting and framing exactly the same. Both the Rodenstock and the Mamiya were/are in genuine mint condition so they should be representative of what each lens can do. I'll start a new thread for the comparison and post the crops late tomorrow morning.

I can tell you ahead of time that they will be shot on the Actus G with a Nikon Z7 body, camera in landscape orientation; two rows of three images per row. The Actus seems to go a bit past 20 shift each side - about 22mm - so these images will reflect a virtual sensor about 80mm wide vs the Mamiya IC at 95mm and the Rodie at 125mm.

If you want anything specific, i.e. aperture etc. let me know, otherwise it will be f/11 and refocus each frame in the centre for each shot.

Cheers,
Steve.

Thank's a lot Steve, I am really looking forward to these shoots!
For me f/8 would be nice, but I guess that for most people f/11 is of greater relevance , so do not bother if it is too complicated to shoot, process and post with two different apertures.
Cheers
Vincent

 

[vvince]

Hi Vincent,

I've got some comparisons for you between the Mamiya M ULD 50mm f/4.5 and the Rodenstock 55mm Apo-Sironar digital f/4.5. I think they illustrate the lens cast you can expect and the comparative sharpness across the frame, including the edges.

I think they make my case but I'm going to reshoot them in the morning here in Brisbane, Australia because I want the lighting and framing exactly the same. Both the Rodenstock and the Mamiya were/are in genuine mint condition so they should be representative of what each lens can do. I'll start a new thread for the comparison and post the crops late tomorrow morning.

I can tell you ahead of time that they will be shot on the Actus G with a Nikon Z7 body, camera in landscape orientation; two rows of three images per row. The Actus seems to go a bit past 20 shift each side - about 22mm - so these images will reflect a virtual sensor about 80mm wide vs the Mamiya IC at 95mm and the Rodie at 125mm.

If you want anything specific, i.e. aperture etc. let me know, otherwise it will be f/11 and refocus each frame in the centre for each shot.

Cheers,
Steve.

You probably already have shot these pictures, so It might be to late now, but just in case : a reference (unshifted) picture with a native FF lens (e.g. Nikon) would be nice too.

 

[stevev]

Not sure of the equivalency but I'm guessing that would mean about 100mm? I have the 70-200 f/4 so I can use that to shoot the central image in the 3x3 grid of images I used to make the final stitched scene, matching the angle of view - if that is what you need.

 

[vvince]

Not sure of the equivalency but I'm guessing that would mean about 100mm? I have the 70-200 f/4 so I can use that to shoot the central image in the 3x3 grid of images I used to make the final stitched scene, matching the angle of view - if that is what you need.

No need anymore, the idea was to have a reference picture from a "modern" lens adapted to the sensor of your camera (one pic of the centre scene only, at the same focal lens, 50mm).
I just saw your post with the results (great comparison and report, thank's a lot!!)

Mamiya RZ67 50mm M ULD F/4.5 vs Rodenstock 55mm APO-Sironar Digital F/4.5

This comparison has been of interest in the forums recently so I made some comparison shots today. If you are looking for a wide lens to use with a Cambo Actus these two lenses may be under consideration for some. The Mamiya has an image circle of 95mm and the Rodenstock's is much larger at...

www.getdpi.com

and your picture with the "mystery lens" gave us this reference.

 

[Happyconch]

Vincent,

Both of these were taken with the Cambo Actus G and Mamiya 50mm M ULD, using a Z7 as the "back". It is a great combination. With a S1R on the back I can get over 36,000 pixels across...

Cheers,
Steve.

View attachment 181620

View attachment 181621

Steve,

After checking your files, I decided to buy the Mamiya 50mm ULD and the Mamiya RB67 lensboard for my Actus-G.
Stupid question: how do you change the aperture?
My Pentax 645 lensboard has a small contraption to change the lens aperture, but I don't see any similar way to control the Mamiya lens.

Thanks

Claude

 

[stevev]

Hi Claude,

The RZ67 50mm ULD lens has a manual aperture ring, so you should have no problems.

Cheers,
Steve.

 

[Happyconch]

Thanks, Steve. Very nice of you.
The change of aperture using the ring has no effect until I use the lens lever to stop down. Not very practical.
Last night I found a tip provided by the Cambo website: uncock the shutter, then set it to T and open it with a cable release. "After that, it remains open and you can use the aperture ring".
Voila...
Now waiting for my mechanical cable release...

 

[vvince]

Claude, no need for a cable release.
If you set the shutter to T before uncocking the shutter, it will open to the set aperture directly.

Cheers
Vincent

 

[Happyconch]

Thanks Vincent! You are a lifesaver!
I just tried that and it works perfectly.
Thanks for taking the time to answer.

Claude