MF Lenses with Shift Adapter or RhinoCam on Full-Frame/35mm Digital Body

[rdeloe]

120 degrees, wow, not sure how you managed to calculate this but it sounds pretty &%€#"! mind-blowing!!

It's mm, not degrees -- so 120mm. That's still a big image circle though for a lens at that focal length. I won't be surprised if Pentax made it a bit bigger to help the edges be decent when shifted to the maximum on a Pentax 67 camera.

You can estimate the size of the image circle with the help of our old pal Pythagoras. The size of the image circle needed to cover a sensor (or film) is the diagonal of the rectangle. The imaged area on a piece of 6x7 film is around 58mm x 68mm. Therefore, the diagonal of that rectangle is 89.4mm (I rounded up to 90mm). If you imagine a long, skinny rectangle that is the original 58mm x 68mm plus 20mm on either side (so a rectangle that is 58mm tall and 108mm wide -- which is what you get by shifting 20mm left and 20mm right), then the diagonal of that is 122.6mm. I came up with 120mm by sketching it in PowerPoint and eyeballing the circle needed to cover -- but the math way is more accurate.

Thanks for this very useful answer. With the help of these great diagrams together with the detailed explanation, even I can understand this.

LIke many others I am finding that being stuck at home in these unusual times is a good opportunity to look into the technical aspects of photography with the hope that some day it will be possible to get back out in the big world beyond the back fence and appy what I have learned.

Meanwhile, I have ordered a TLT ROKR to try out with an old 55mm Super Takumar bazouka I have in my dry cabinet to see how stitching with that on my fullframe Sony mirrorless looks, and "if" that works will further consider piggybacking the shift adapter with a shift lens.

When I look here at the specs for the SMC-Pentax-67-75mm-F4.5-Lens it says:
Field of View (Diag. / Horiz.)
61 ° / 50 °

Whereas the wider angle SMC-Pentax-Takumar-6x7-55mm-F3.5 has:
Field of View (Diag. / Horiz.)
78 ° / 65 °

Remember these angles of view are for the native "sensor": 6x7 film.

Given this, I am uncertain but would like to know how much difference in the "field of view" I could expect to see in a stitched panorama with a full frame mirrorless camera between (a) "120°" of the SHIFTED P67 75mm lens + TLT ROKR vs (b) X° of the UNshifted P67 55mm lens + TLT ROKR.

No doubt the best way to find out what this may look like is by trying it out and see what happens, but not if the difference in look and coverage of (a) vs (b) is not likely to be telling enough to be worth investing in more gear.

I'm going to take a stab at the math here. Hopefully someone actually math-competent can check my work.

If you put a 75mm lens on your full frame camera and shift it 20mm left, then 20mm right (like you could with the P67 shift lens), you end up with a rectangle that is 76mm long and 24mm high. The angle of view across that 76mm long edge is 53.7 degrees*. A 35mm lens on full frame, long edge with no shift, has an angle of view of 54.4 degrees. So in terms of angle of view, a 75mm lens shifted 20mm left and 20mm right to create a long skinny panorama on full frame has an angle of view about the same as a 35mm lens on full frame unshifted.

This gives you an idea for what you can do with the Pentax 67 75mm shift lens -- all assuming that there's no mechanical vignetting and the image quality isn't crap because of the extreme angle of the beam. Those are big "ifs".

If you put a 55mm lens on a full frame camera, the angle of view for the long edge, unshifted, is 36.2 degrees. Remember that it doesn't matter what format the lens was designed for -- 55mm is 55mm. I believe that P67 to Sony E FotoDiox TILT-ROKR adapter can only shift 10mm. If you shift your P67 55mm lens 10mm left and 10mm right on full frame, you'll get a rectangle that is 56mm wide. The angle of view on the long edge of this rectangle would be 54 degrees -- again, about the same angle of view as a 35mm lens on full frame with no shift.

Once you get your adapter and start playing around with it, keep in mind that among the P67 55mm lenses, you have the worst of the bunch. Don't judge what is possible with P67 lenses with that one. The third generation P67 55mm lens was completely redesigned, and is much better. I've used it on a GFX camera and closed down a couple stops it keeps up with the Fuji lenses.

One last thought on lens choices: if you get the P67 75/4.5 shift lens, I seriously doubt you'll be able to take advantage of all the shift capacity it provides on the Tilt-ROKR adapter. There's a reason Fotodiox limited their adapter to 10mm. What you would get is shift independent from the direction of tilt; now that's actually quite handy if you start using tilt. You could also start doing things like shifting the adapter up, and then using the shift lens to do the shifting; that would allow you to flat stitch rows of panorams together to create larger files.

* If you have Excel, the formula is as follows: =DEGREES(2*ATAN(Edge/(2*FocalLength)))

 

[lowep]

Oiks, thanks for pointing this out (most others would not be so patient). Maybe time for me to put aside the Ginsberg biography and put the bottle back in the brown paper bag? I am heartened by your conclusion (if I understand right) that both the p67 75/4.5 shift lens with 20mm shift and the p67 55mm with 10mm TLT-ROKR shift deliver about the same angle of view as a 35mm lens on full frame with no shift - even if the P67 55/3.5 is an old dog. I figure if nothing else carting around this P67 55/3.5 lens will be as good as doing aerobics, and it will also be more useful in a bar fight.

So far I have only tried panorama stitching with a panoramic tripod head. That works quite well. The reason I am looking into using camera/lens shift for panorama stitching is for the next thing I want to do I don't need that much panorama, a final image with 6x12 ratio will do fine, and I am quite interested in seeing what that final image will end up looking like compared to doing roughly the same thing with a panoramic tripod head. Perhaps I will not need to depend so much on Photoshop torturing the original images to stitch them together? Plus as you mention being able to tilt as well as shift opens up worlds of new possibilities.

 

[rdeloe]

Oiks, thanks for pointing this out (most others would not be so patient). Maybe time for me to put aside the Ginsberg biography and put the bottle back in the brown paper bag? I am heartened by your conclusion (if I understand right) that both the p67 75/4.5 shift lens with 20mm shift and the p67 55mm with 10mm TLT-ROKR shift deliver about the same angle of view as a 35mm lens on full frame with no shift - even if the P67 55/3.5 is an old dog. I figure if nothing else carting around this P67 55/3.5 lens will be as good as doing aerobics, and it will also be more useful in a bar fight.

That's correct (assuming my math is correct!) The big "however" here is that I'm really doubtful that you can get a usable 20mm of shift. I have to think Fotodiox limited their adapter to 10mm when other similar adapters for other lens mounts and cameras have 12-15mm because of mechanical vignetting concerns. Those won't disappear just because you can shift 20mm on the P67 75/4.5 shift lens. If you're looking for a 6x12 aspect ratio, this is not a limitation: 6mm one way, 6mm the other way, and you have the 48mm you need.

I almost hate to muddy the water at this point, but if you really only want 6mm of lateral shift either side of neutral, you could get that using Pentax 645 lenses. The SMC Pentax-A 645 35/3.5 is excellent and doesn't cost a lot. The SMC Pentax-A 645 45-85mm f/4.5 is excellent from 45mm to around 75mm, still great from 75mm to 85mm, and dirt cheap. Here's a test shot I made to see how this lens shifts. This is f/11 on my Fuji GFX 50R, at around 57mm, focused at a target 4km in the distance, with 15mm of shift to either side of neutral. Click on the picture to download a full resolution JPEG. With a Fotodiox Tilt-ROKR for Pentax 645 to Sony E you're still only getting 10mm of shift, but that's bogus because with different adapters I've shifted Pentax 645 lenses 15mm on a Sony A7R. There may be ways around that by pairing up adapters. Anyway, there are lots of options.

So far I have only tried panorama stitching with a panoramic tripod head. That works quite well. The reason I am looking into using camera/lens shift for panorama stitching is for the next thing I want to do I don't need that much panorama, a final image with 6x12 ratio will do fine, and I am quite interested in seeing what that final image will end up looking like compared to doing roughly the same thing with a panoramic tripod head. Perhaps I will not need to depend so much on Photoshop torturing the original images to stitch them together? Plus as you mention being able to tilt as well as shift opens up worlds of new possibilities.

The kind of photography you can do with a shift adapter is often called "flat stitching". When you move the sensor and the lens stays put, you don't have any issues with parallax. What you see is what you get. That's why you always want to lock the lens side of a shift adapter to the tripod, and then move the camera left and right (or up and down), rather than putting the camera on the tripod and then moving the lens. Notice on the Fotodiox adapter how they installed a tripod foot on the lens side (which is good).

The down side of this arrangement is with your tripod in the normal position (head up) you are locked into tilt and shift movements. That's not a problem for someone who actually wants to tilt and shift more than "swing" and rise/fall (the opposite movements). You can of course just flip the adapter sideways, but that puts the camera and lens awkwardly on the side of the tripod, which is unstable. It's for this reason that I threw away the foot on my tilt-shift adapter and built a collar that goes around the front of the adapter. But that's a whole other thing you can worry about if you find this is a useful path.

 

[lowep]

Thanks Rob, it is very encouraging to get the benefit of your experiences on this curvy path. Now I have a much better understanding of constraints and opportunities I may encounter along the way. I was very happy for the image you uploaded that helps me understand much better what happens when the numbers are translated into an actual image. I do have a legacy MFDB but for the moment I want to see what is possible when trying to use my old P67 55mm lens, new incoming TLT ROKR adapter and full frame mirrorless with all its bells and whistles as a defacto MFDB-slash-oldstyle-analog-panorama-camera, by using shifts, and am also very interested to see what flat stitching looks like, so lots to learn.

 

[lowep]

Just to be sure I understood right Rob, you mention the result of piggybacking 20mm shift with the P67 75mm shift lens + 10mm shift with the TILR ROKR is tough to predict but seems like your guesstimate is there may be a good reason why the good folks at fotodiox were NOT ready to countenance the consequences of such extreme shift when they limited the design of their adapter to 10mm - ie the photographic equivelant of doing loop the loop in a cargo plane?

I see the Zork panorama shift adapter "permits up to 20mm of shift, whereas most dedicated PC / TS lenses allow 8-10mm" but that doesn't necessarily mean the results look good.

 

[rdeloe]

Just to be sure I understood right Rob, you mention the result of piggybacking 20mm shift with the P67 75mm shift lens + 10mm shift with the TILR ROKR is tough to predict but seems like your guesstimate is there may be a good reason why the good folks at fotodiox were NOT ready to countenance the consequences of such extreme shift when they limited the design of their adapter to 10mm - ie the photographic equivelant of doing loop the loop in a cargo plane?

I see the Zork panorama shift adapter "permits up to 20mm of shift, whereas most dedicated PC / TS lenses allow 8-10mm" but that doesn't necessarily mean the results look good.

I am speculating on this, but I'm thinking that Fotodiox limited it to 10mm because of the design of their adapter. If I had to guess I'd say they noticed that with more than 10mm of shift, there's mechanical vignetting. There's absolutely room on the adapter for a longer geared mechanism to allow for greater shift. For example, the much smaller Kipon t/s adapter I used to use on my Fuji X-T2 allowed for 15mm. Or it might have been an arbitrary decision. It really is hard to know.

The fact that Zork allows for more will be a function of the design of their adapter. For instance, the "adapter" I'm using (a Toyo VX23D digital view camera) allows a bit over 60mm of shift. That doesn't mean I can use that much (I can't). My GFX 50R has a flange distance of 26.7mm, so the sensor is deep inside a cavity in the body of the camera. The beams of light transmitted by the shifted lens hit the edge of the cavity long before I run out of shift room or image circle on some lenses.

For what it's worth, on my former A7R full frame tilt-shift outfit, I used two stacked adapters from Mirex (the people who invented the t/s adapter). One was P645 to Canon EOS, and the other was Canon EOS to Sony A7R. They used Canon EOS because that mount has the largest throat. With that combination, I was able to shift 15mm easily using Pentax 645 lenses. There was no mechanical vignetting.

 

[ggibson]

As I shared earlier in the thread, I've been combining two adapters (Hasselblad-Canon EF-Sony E) and achieving shifts up to +/-25mm with non-shift lenses. I do believe that at the more extreme ends of this, the adapters are causing some soft vignetting. This can be corrected in post and doesn't cause any issues with stitching. As I mentioned earlier in the thread though, the Hasselblad 50/4 gave me some hard vignetting which if I recall was with horizontal+vertical shift combined. Still, I'm guessing you'd be fine with just the single shift adapter even if the 75mm lens is shifted.

For a "6x12" ratio image (1:2), you could work in a single row by turning the camera into portrait mode and shifting +/-24mm horizontally, giving you a flat stitch covering around 36mm x 72mm. I tried these shifts with my Hasselblad 80/2.8 on my A7rII today. There's a bit of soft vignetting towards the edges on the Hasselblad image, which I was able to correct and had no problem using Lightroom's automatic stitching. The shot below is edited for taste, not straight out of camera. The Hasselblad lens is not nearly this contrasty, but it provides sharp images even wide open. The full original file is 15,856 x 7,928 (125MP resolution).


Hasselblad 80/2.8 Stitch by Graham Gibson, on Flickr

The result is similar to a native 40mm lens on the Sony, cropped down to the 1:2 ratio. Here's my Voigtlander 40/1.2 at f1.4:

Voigtlander 40/1.2 by Graham Gibson, on Flickr

And a couple of fun images with the lens/adapter set on tripod:

Dual Fotodiox shift adapters by Graham Gibson, on Flickr


The camera's view by Graham Gibson, on Flickr

 

[lowep]

Thanks Graham for posting these images, seeing is believing!

 

[lowep]

Swebo TC-18 is the least expensive option at about $1,000 with a medium-format lens board, but it gives +/-50mm of shift/rise/fall on both standards and tilt on both standards. If you just want shifts, Swebo has a less expensive model with just shifts.

Thanks Shashin for pointing this out! It is is quite an intriguing possibility, with more movement than a shift lens and less clunky though harder to find and quite a bit more expensive to explore than just mounting a mirrorless fullframe camera like my Sony A7RII on my old Graflex Crown Graphic. Have you actually tried using this Swebo TC-18 or just read about it? What is the less expensive model with just shifts?

 

[Shashin]

Thanks Shashin for pointing this out! It is is quite an intriguing possibility, with more movement than a shift lens and less clunky though harder to find and quite a bit more expensive to explore than just mounting a mirrorless fullframe camera like my Sony A7RII on my old Graflex Crown Graphic. Have you actually tried using this Swebo TC-18 or just read about it? What is the less expensive model with just shifts?

I don't know much about it right now, but I have one on order and should be arriving next month. The less expensive model is just shifts. The only thing on this camera I can find is on an Amazon review and a DPreview thread--both by the same person. The company has a Facebook page, but I don't have a Facebook account.

 

[lowep]

For anybody else who (like me) is not so good at math, or just lazy, you can scroll down almost to the end of this page to find a very useful online tilt-shift lens calculator.

 

[lowep]

If you shift your P67 55mm lens 10mm left and 10mm right on full frame, you'll get a rectangle that is 56mm wide.

Taking this into consideration, I am trying to guesstimate if piggy-backing an additional shift adapter like the Fotodiox EF to E-mount TLT ROKR to add an extra 10mm left and 10mm right shift would be within the limits of this lens, as it seems to be with the Hasselblad lens that Graham is using.

 

[rdeloe]

Taking this into consideration, I am trying to guesstimate if piggy-backing an additional shift adapter like the Fotodiox EF to E-mount TLT ROKR to add an extra 10mm left and 10mm right shift would be within the limits of this lens, as it seems to be with the Hasselblad lens that Graham is using.

I may have misled you into thinking I'm good at math... That is not the case! But this I can explain.

Pentax 6x7 lens cover roughly 90mm. If you took the diagonal of a 60mm x 70mm rectangle, you'd get 92.19mm, but the image area on 6x7 is closer to 58mm x 68mm (or less depending on the camera). So I us 58mm x 68mm to get to 90mm image circle.

If you want to shift 20mm on full frame, in landscape, you need to figure out the diagonal on a rectangle that is 20mm + 36mm + 20mm -- so 76mm x 24mm. If you have Excel, the formula is as follows: =SQRT(76^2+24^2) This is of course c2 = a2 + b2 where "a" is 76 and "b" is 24. The 2 is supposed to be superscript but the forum software doesn't let me do superscripts.

The diagonal of that 76mm x 24mm rectangle is 79.7mm -- so good news, it falls well within the image circle of the Pentax 67 lens.

Will image quality be acceptable at the far shifted edge? That I cannot say. You're not near the edge of the image circle, but the beams of light will be hitting the sensor at an angle, which (depending on the sensor) can create problems. The good news is the Pentax 67 system has a really long flange distance of 85mm, so it's not like the rear of the lens is close to your sensor. I think you'll be fine, but you'd have to try to really see. Expect to work at f/11 or f/16 for best results. You'll also have to figure out where to focus in the shifted area; if there's some field curvature inherent to the lens, you shouldn't assume you can just focus for the central image and then shift.

 

[ggibson]

I may have misled you into thinking I'm good at math... That is not the case! But this I can explain.

Pentax 6x7 lens cover roughly 90mm. If you took the diagonal of a 60mm x 70mm rectangle, you'd get 92.19mm, but the image area on 6x7 is closer to 58mm x 68mm (or less depending on the camera). So I us 58mm x 68mm to get to 90mm image circle.

If you want to shift 20mm on full frame, in landscape, you need to figure out the diagonal on a rectangle that is 20mm + 36mm + 20mm -- so 76mm x 24mm. If you have Excel, the formula is as follows: =SQRT(76^2+24^2) This is of course c2 = a2 + b2 where "a" is 76 and "b" is 24. The 2 is supposed to be superscript but the forum software doesn't let me do superscripts.

The diagonal of that 76mm x 24mm rectangle is 79.7mm -- so good news, it falls well within the image circle of the Pentax 67 lens.

Will image quality be acceptable at the far shifted edge? That I cannot say. You're not near the edge of the image circle, but the beams of light will be hitting the sensor at an angle, which (depending on the sensor) can create problems. The good news is the Pentax 67 system has a really long flange distance of 85mm, so it's not like the rear of the lens is close to your sensor. I think you'll be fine, but you'd have to try to really see. Expect to work at f/11 or f/16 for best results. You'll also have to figure out where to focus in the shifted area; if there's some field curvature inherent to the lens, you shouldn't assume you can just focus for the central image and then shift.

Are you sure you're not thinking of Pentax 645 covering 90mm? I had read my Hasselblad 80/2.8 covers around 102mm.

Some reading on a largeformatphotography forum post shows people saying P67 lenses come close to covering 4x5, and the 75/4.5 shift lens (which obviously has an even larger image circle) can cover it (>153cm).

I think the dual adapters occluding each other become the limiting factor when trying to shift as far as I showed in my example. It's hard to know how well this will work depending on the lenses, mounts, and adapters. A setup like the Swebo seems to be better if you want to try shifting farther.

 

[rdeloe]

Are you sure you're not thinking of Pentax 645 covering 90mm? I had read my Hasselblad 80/2.8 covers around 102mm.

Some reading on a largeformatphotography forum post shows people saying P67 lenses come close to covering 4x5, and the 75/4.5 shift lens (which obviously has an even larger image circle) can cover it (>153cm).

I think the dual adapters occluding each other become the limiting factor when trying to shift as far as I showed in my example. It's hard to know how well this will work depending on the lenses, mounts, and adapters. A setup like the Swebo seems to be better if you want to try shifting farther.

You need an image circle of 160mm to just barely cover 4x5. None of the standard Pentax 6x7 would have an image circle that large. The 75mm shift will have a much bigger circle, but I'm skeptical it covers 4x5. I've never owned it, but it only needs 120mm to cover the specified shift range. Primes tend to be close to their minimum necessary coverage.

It's true that many zoom lenses have larger image circles in the middle of their zoom range. My SMC Pentax-A 645 45-85mm f/4.5 has a tight image circle at 45mm, just covering 645 film, but at around 60mm it's larger by at least 10mm. It then shrinks back down to the minimum size needed as you approach 85mm. I bet the Pentax 67 55-100mm f/4.5 has a bigger circle in the middle than at either end, but still not close to big enough to cover 4x5.

I'm using a Mamiya G 50/4.5 on my Fuji GFX 50R. The Mamiya 6 for which it is designed is also a 6x6 film camera, like your Hasselblad. I've measured the image circle quite carefully, and it's only as large as is needed to cover the imaged area of 6x6 film, in other words, 82mm. I can shift 15mm before I'm seeing the rim of the lens, and vignetting hard. I'm not saying you're wrong about your Hasselblad 80/2.8 covering 102mm, but I would find that astonishing because that would mean Hasselblad's lens designers decided to make an image circle vastly larger than needed to cover the film. You could cover an 85mm x 85mm piece of film with a 120mm image circle. I don't see why they would do that.

 

[Shashin]

A 6x6 frame is 56mm x 56mm. 6x4.5 is 56mm x 42mm. 6x7 is 56mm x 67mm.

 

[Audii-Dudii]

You need an image circle of 160mm to just barely cover 4x5. None of the standard Pentax 6x7 would have an image circle that large. The 75mm shift will have a much bigger circle, but I'm skeptical it covers 4x5. I've never owned it, but it only needs 120mm to cover the specified shift range. Primes tend to be close to their minimum necessary coverage.

FYI, the 75/f5.6 lens for the Mamiya Press and Polaroid 600SE cameras actually does come very close to covering the 4x5 format at closer focusing distances. I happily used one for several years as part of my medium-format view camera outfit, although when I tried it with my A7R and Toyo 23G-based FrankenKamera, it clearly was showing its limitations.

Anyway, the Press camera uses the 6x9 format, which requires an approx. 100 mm image circle to cover. Perhaps the P67 75/f4.5 shift lens is based on this design, hence its oversize image circle?

 

[ggibson]

You need an image circle of 160mm to just barely cover 4x5. None of the standard Pentax 6x7 would have an image circle that large. The 75mm shift will have a much bigger circle, but I'm skeptical it covers 4x5. I've never owned it, but it only needs 120mm to cover the specified shift range. Primes tend to be close to their minimum necessary coverage.

It's true that many zoom lenses have larger image circles in the middle of their zoom range. My SMC Pentax-A 645 45-85mm f/4.5 has a tight image circle at 45mm, just covering 645 film, but at around 60mm it's larger by at least 10mm. It then shrinks back down to the minimum size needed as you approach 85mm. I bet the Pentax 67 55-100mm f/4.5 has a bigger circle in the middle than at either end, but still not close to big enough to cover 4x5.

I'm using a Mamiya G 50/4.5 on my Fuji GFX 50R. The Mamiya 6 for which it is designed is also a 6x6 film camera, like your Hasselblad. I've measured the image circle quite carefully, and it's only as large as is needed to cover the imaged area of 6x6 film, in other words, 82mm. I can shift 15mm before I'm seeing the rim of the lens, and vignetting hard. I'm not saying you're wrong about your Hasselblad 80/2.8 covering 102mm, but I would find that astonishing because that would mean Hasselblad's lens designers decided to make an image circle vastly larger than needed to cover the film. You could cover an 85mm x 85mm piece of film with a 120mm image circle. I don't see why they would do that.

http://www.hasselbladhistorical.eu/PDF/HasManuals/Flexbody.pdf

Flexbody manual gives some shift info, the 80/2.8 is +/-10mm. The diameter needed to cover 6x6 is around 79.2mm 85mm by my math (56mm * sqrt(2)). So adding 20mm to that is 105mm coverage. Am I calculating that correctly?

 

[rdeloe]

A 6x6 frame is 56mm x 56mm. 6x4.5 is 56mm x 42mm. 6x7 is 56mm x 67mm.

I kept the negatives from various medium format cameras I've used.

• Yashica Mat: 57mm x 57mm
• Mamiya RZ67 Pro II: 56mm x 70mm
• Fuji GW690: a very stingy 56mm x 82mm (so much for 6x9)

 

[rdeloe]

http://www.hasselbladhistorical.eu/PDF/HasManuals/Flexbody.pdf

Flexbody manual gives some shift info, the 80/2.8 is +/-10mm. The diameter needed to cover 6x6 is around 85mm by my math (56mm * sqrt(2)). So adding 20mm to that is 105mm coverage. Am I calculating that correctly?

When I calculate the diagonal of a 56mm x 56mm square I get 79.196mm. To get 85mm diagonal the square would have to be 60mm x 60mm.

If one can get +/-10mm of shift on film using an 80/2.8 on that Flexbody, that means the lens has an image circle of 106mm (by my calculation, and working with their dimensions of 55mm x 55mm for film area). That's a lot of extra image circle! But I did notice that the manual doesn't say the subject distance. The image circle grows as we approach 1:1. Can you get +/-10mm of shift on film at infinity? If so, that is indeed a very generous circle. It certainly gives you tons of shift room on a full frame sensor.

Another consideration is they specify f/16, which means they're really pushing the limits. Presumably the circle of good definition is only good enough at f/16.