Anybody using Rodenstock Apo Sironar (non HR) or Grandagon with small pixels?

[Theodoros]

I'm interested to know the following (especially for 35,45 & 55mm focal lengths):

1. How well do the lenses cope with pixels of around 7μm pitch and then with smaller...
2. What is the image quality difference with respect to the HR series of lenses.
3. How vignetting develops with respect to the image circle.
4. How do they cope with MF Cmos sensors and with Sony α7...
5. What is the difference (if any) between the two series (Apo Sironar and Apo Grandagon) as on paper they look the same.


Thanks.

[JoeKitchen]

I have used the Rodie 55m an the IQ260 several times and never have had an issue. 

Recently my fiance has been doing a personal project with that lens where she needs to capture macro images.  So far, she has focused as close as 5 to 6 inches without any loss to sharpness or aberrations.  She is also incorporating quite a lot of shift and tilt.  (Basically she was focusing on a stack of 5 ritz crackers with cheese on top, filling the frame, and needed to make it look very heroic.) 

To be honest, I was quite surprised the lens works as well as it does that close.   

[torger]

I've seen samples of the 55 and it's good and stable. In fact a good copy of a 55 can outperform a bad copy of the SK60XL for large shifts. You don't have the crispiness for unshifted shots as a modern lens though. If you shoot at f/16 the differences evens out quite well.

I've owned the Sironar-Digital 35mm, but I was not happy with its performance when shifted so I sold it and got a SK35XL instead. The 55 compares better to the digital alternatives than the 35 do.

I don't know anything about the 45. Maybe it's similar to the SK47XL?

I don't know how they perform on CMOS. Must probably very similar to the Schneider Digitar series though so you can look at results for those which are a bit easier to find.

[Theodoros]

I've owned the Sironar-Digital 35mm, but I was not happy with its performance when shifted so I sold it and got a SK35XL instead.

Hi Anders, could you please be more specific on the differences between the two?  How do image circles compare and how vignetting compares? Is there a need for a center filter with the SK 35XL?  Is the SK35XL sharper? Will the SK35 cope with 6x9 film?

[voidshatter]

I have tested the ALPA AAA Apo-Alpar 4.5/35 mm (part number 160.028.060) on an IQ250 44x33 50MP CMOS.

Some observations:

a) The lens is very flare-resistant and virtually distortion free (and very light-weighted).

b) LCC in Capture One 9.2 clears the color cast nicely without desaturation issues even when the lens is shifted.

c) Center resolution is very nice.

d) Edge and corner performance is very poor due to astigmatism caused by sensor cover glass.

Conclusion: Pick the Rodenstock HR Digaron series instead for use on a CMOS sensor, and stay away from these legacy lenses.

[Theodoros]

I have tested the ALPA AAA Apo-Alpar 4.5/35 mm (part number 160.028.060) on an IQ250 44x33 50MP CMOS.

Some observations:

a) The lens is very flare-resistant and virtually distortion free (and very light-weighted).

b) LCC in Capture One 9.2 clears the color cast nicely without desaturation issues even when the lens is shifted.

c) Center resolution is very nice.

d) Edge and corner performance is very poor due to astigmatism caused by sensor cover glass.

Conclusion: Pick the Rodenstock HR Digaron series instead for use on a CMOS sensor, and stay away from these legacy lenses.

Thanks for the examples posted...

What if the sensors used with it are of 22 & 39mp Kodak sensors of 37x49size with no microlenses?

[torger]

Hi Anders, could you please be more specific on the differences between the two?  How do image circles compare and how vignetting compares? Is there a need for a center filter with the SK 35XL?  Is the SK35XL sharper? Will the SK35 cope with 6x9 film?

The SK35XL does not have superlarge image circle either, it's rated to 90mm, but I'd say about 75mm of it is high quality, the rest is pretty fuzzy. As it's symmetric and wide it needs a center filter. I think 6x9 film is slightly too large for it, but I'm not 100% sure. The 35XL is a very sharp lens in the center and up to about say 70mm then it softens acceptably to 75mm, and outside 75 it's not that good.

I don't remember exactly the behavior of the Rodenstock Sironar 35 but it was less sharp in the center area and also less sharp when shifted, I would not be surprised though if it still works better in the 75-90mm range as the SK35XL is pretty weak there.

If you search the net you may be able to find datasheet for both lenses that could answer the your questions more exactly.

The strong point of the SK35XL is that its virtually distortion free and it's small and light, and is relatively inexpensive for being a wide angle, and if you keep within about 75mm image circle the sharpness is competitive with the best wides.

The SK35XL works excellently regarding LCC correction on the Kodak 22, 39, 50 sensors with no microlenses. For more recent sensors the Rodenstock Digarons are strongly recommended.

[tjv]

I use an RS 55mm APO-SD with a Credo 60. I'm actually very surprised at how good it is and as Anders said above, my copy performed better than his SK60XL on large shifts (shooting 1:2 panoramas along with 8mm of fall on the back,) before he sent his lens into to get checked. For those kinds of shifts a 2.5 stop centre filter is essential, else the LCC creates too much noice in the shadows if applying falloff corrections.

For 1:2 panoramic stitches with as much perspetice correction as 8mm fall of the back, shooting a flat subject like a brick wall with make you cry, but in the real world with 3D subjects, it's a good lens.

[Theodoros]

I don't remember exactly the behavior of the Rodenstock Sironar 35 but it was less sharp in the center area and also less sharp when shifted, I would not be surprised though if it still works better in the 75-90mm range as the SK35XL is pretty weak there.

I'm sorry to insist Anders but the 35mm focal length is the one that is puzzling me most than any of the others... Perhaps it's best for me to describe the use I want it for and then you may suggest better which of the two (the Sironar 35 or the SK35XL will suit me best...

I will be using the lens for demanding internal architecture with the Sinarback 54H and Hasselblad CF-39MS backs, sometimes in multishot mode too with fluorescent CRI>97 daylight lighting... I'm not concerned for the maximum possible of resolution as long as I have enough of it, so having more center analysis from the SK wouldn't matter to me as long as the RD is good enough... I'm more concerned as to have enough image circle as to stitch a 90 degrees (horizontal) AOV within the frame... that would be the same as shooting a 35mm on a 74X56mm (6x8) image area... I also care for whatever distortion I get as to be easily correctable in post. Obviously I will be using a center filter with either lens, no problem as to use whatever aperture is best as to extract the best out the lens either. 

Will the distortion be similar between the two lenses? I won't have extra distortion induced by the camera because I have my camera (Sinar P2) converted for optimum results as far as distortions are concerned (all tilts and swings are done on a axis through the entrance pupil of the lens)
You said that the SK isn't good after 75mm of image circle... (that is a real issue for me) It would also mean that there will also be uneven resolution across the frame (another issue). Would the RD 35 be more even across the frame and the resolution -although lower than SK's center- just good enough as not to be an issue? I suspect that with my backs none of the two will have LCC issues... would you say that this is true for the whole AOV of 82x56mm image area used that I require?

[Theodoros]

I hope Anders has seen that, otherwise can somebody else help with the above question?

[Brent Daniels]

One thing you may want to consider with stitching WA lens is that you may be better off using the Scene Calibration tool in Phocus instead of a centre filter. The scene calibration tool will most like clean-up all lens density fall off, plus color shifts, more accurately than a filter as it works off the actual file which may have other digital chip effect factors beyond actual lens light fall off.

I you are going to do a 3 shot left - centre - right stitch it will require 3 files shot for calibration but that can be very simple to do quickly on set. 

[Theodoros]

One thing you may want to consider with stitching WA lens is that you may be better off using the Scene Calibration tool in Phocus instead of a centre filter. The scene calibration tool will most like clean-up all lens density fall off, plus color shifts, more accurately than a filter as it works off the actual file which may have other digital chip effect factors beyond actual lens light fall off.

I you are going to do a 3 shot left - centre - right stitch it will require 3 files shot for calibration but that can be very simple to do quickly on set.

I'm aware of that Brent, but I'm using the Sinarback 54H too alongside the CF-39MS... First priority is to choose between the lenses though... How to extract the most out of it always comes after the decision has been made.

[torger]

I'm sorry to insist Anders but the 35mm focal length is the one that is puzzling me most than any of the others... Perhaps it's best for me to describe the use I want it for and then you may suggest better which of the two (the Sironar 35 or the SK35XL will suit me best...

I will be using the lens for demanding internal architecture with the Sinarback 54H and Hasselblad CF-39MS backs, sometimes in multishot mode too with fluorescent CRI>97 daylight lighting... I'm not concerned for the maximum possible of resolution as long as I have enough of it, so having more center analysis from the SK wouldn't matter to me as long as the RD is good enough... I'm more concerned as to have enough image circle as to stitch a 90 degrees (horizontal) AOV within the frame... that would be the same as shooting a 35mm on a 74X56mm (6x8) image area... I also care for whatever distortion I get as to be easily correctable in post. Obviously I will be using a center filter with either lens, no problem as to use whatever aperture is best as to extract the best out the lens either. 

Will the distortion be similar between the two lenses? I won't have extra distortion induced by the camera because I have my camera (Sinar P2) converted for optimum results as far as distortions are concerned (all tilts and swings are done on a axis through the entrance pupil of the lens)
You said that the SK isn't good after 75mm of image circle... (that is a real issue for me) It would also mean that there will also be uneven resolution across the frame (another issue). Would the RD 35 be more even across the frame and the resolution -although lower than SK's center- just good enough as not to be an issue? I suspect that with my backs none of the two will have LCC issues... would you say that this is true for the whole AOV of 82x56mm image area used that I require?

That it isn't that good outside 75mm are related to modern expectations, eg Rodenstock Digaron performance, it's not like it's totally useless. I have very little experience with the Sironar 35 as I sold it almost immediately after some brief testing, I don't think I have any shot left from it. Usually Rodenstock have a bit more distortion, and I would expect this also from the Sironar, but I don't really know for sure. I don't have enough information to give you an exact answer. Try to find the data sheets and compare the two, I think you will get the answers from there. Unfortunately those are not so easy to find.

LCC issues is not a problem with your backs, it will cancel out color cast fine. You can shift all the way to the hard limit.

[torger]

Here's the datasheets of the SK35XL which I found on my harddrive (attached)

Found this old Rodenstock document when googling which contains data on the Sironar Digital 35:

http://www.linos.com/pages/mediabase/original/rodenstock_apo-sironar_digital_e_2472.pdf

[Theodoros]

That it isn't that good outside 75mm are related to modern expectations, eg Rodenstock Digaron performance, it's not like it's totally useless. I have very little experience with the Sironar 35 as I sold it almost immediately after some brief testing, I don't think I have any shot left from it. Usually Rodenstock have a bit more distortion, and I would expect this also from the Sironar, but I don't really know for sure. I don't have enough information to give you an exact answer. Try to find the data sheets and compare the two, I think you will get the answers from there. Unfortunately those are not so easy to find.

LCC issues is not a problem with your backs, it will cancel out color cast fine. You can shift all the way to the hard limit.

...But it won't be very even will it? I mean the RD may be more even if it is of significantly less resolution in the center but better at the edges of the 8x6 frame... Could that be true?

[torger]

...But it won't be very even will it? I mean the RD may be more even if it is of significantly less resolution in the center but better at the edges of the 8x6 frame... Could that be true?

Yes that could be true, and it should be possible to figure out from the datasheets above.

[Theodoros]

Yes that could be true, and it should be possible to figure out from the datasheets above.

I was typing before I could see them... Thanks.

[torger]

I was typing before I could see them... Thanks.

I'm no expert at reading MTF charts, but it seems to me that indeed the Sironar could be a better choice for that large image area. It's less sharp in the center for sure, but doesn't have as sharp decline towards the image circle edge. The largest recommended imaging area for the Sironar according to that document is 46x58mm, but it has a 105mm image circle so you should be able to force in more. Your 74x56mm is 93mm diagonal, it should fit and surely less of a disaster than the SK35XL at that diameter.

[Theodoros]

I'm no expert at reading MTF charts, but it seems to me that indeed the Sironar could be a better choice for that large image area. It's less sharp in the center for sure, but doesn't have as sharp decline towards the image circle edge. The largest recommended imaging area for the Sironar according to that document is 46x58mm, but it has a 105mm image circle so you should be able to force in more. Your 74x56mm is 93mm diagonal, it should fit and surely less of a disaster than the SK35XL at that diameter.

Yes, I think my conclusions are the same... Thanks Anders, There are no more replies required in this topic! Thank you all for your contribution.