Sharp 75mm (no diffraction) ???

[Anders_HK]

Hi,

I have a Nikkor 75mm f/4.5 SW and have now used it for digital and run into problems of diffraction also at around f/11. My Rodenstock 150 Sironar-N f/5.6 is sharper at f/5.6-16. Thus... I need trade it for another 75mm...

What would you recommend, and why? Please give me advise on OLD/NEW;

A) Schneider Super Angulon f/5.6 MC or not MC

B) Rodenstock Grandagon /N f/4.5

C) Other choices


and, in regards to

1) sharpness/diffraction

2) Focus shift (depth of field is shallow and focus need be very exact with digital)


Much Kind Thanks!!!

Anders

[Lynn Jones]

Hi HK

I have my suspicians. If this lens isn't designed for digital (field flatening for example) then the losses will be quite substandial while not remarkable for a 150mm.

Sensors require light rays to be perpendicular to their face. Angular rays that are off by a few degrees are not recorded or at best partially recorded. That is why all early digital cameras (except Olympus) lost 30% to 40% of their image resolution. Over time, first Olympus, then Sony, then Tamron, and finally the rest realized that field flatening elements were required for effective use of digital optics.

If you add to this that "superwide" lenses were optimized for 1:1 and could not be used effectively for focus distances farther than the hyperfocal distance then horrendous field curvature problems occur.

Lynn

[Leonard Evens]

As Lynn noted, lenses not designed for digital can sometimes produce problems when used with a digital back. That is why manufacturers such as Schneider and Rodenstock makes `digital lenses', in addition to their regular line of large format lenses, which are optimized for use with the sensor arrays in such backs. But these lenses typically don't cover the full 4 x 5 frame. In addition, when used with the larger digital backs, e.g. 72 x 96 mm, they may not allow much movement. The Schneider Digitars seem to do better in this regard than the Rodenstock digital lenses.

I'm not sure what you mean by diffraction. The problem with digital backs and standard lenses is that the sensors don't work very well for light coming at a large angle. Diffraction doesn't have much to do with that.

[Brian Ellis]

Please don't take this the wrong way, it's meant to be helpful, not offensive. But based on a couple other things you say here I'm wondering whether you understand what diffraction is, what causes it, and how it shows up in a print. It would be useful if you provided more information (e.g. what digital camera are you using and what size prints you're making) and if you could post a photograph or two. It's unusual for the effects of diffraction to be objectionable at f11, especially if your camera doesn't have a full-frame sensor.

In general, the 75mm Nikkor SW is an excellent lens and is the equal of the others you mention. I'd be a little surprised if any of them were any better in terms of diffraction than the one you have but then I'm not a lens expert either.

All other things affecting depth of field being equal, I'm not aware that depth of field is inherently shallower with a digital camera than with a film camera.

All other things being equal, a multi-coated lens is better than a single coated or non-coated lens in terms of flare (which isn't the same thing as diffraction).

[Anders_HK]

Hi,

Thanks for above replies and let me clarify;

I use it with a Leaf Aptus 65 digital back (28.6MP on a 44x33mm sensor).

My use is for panoramix stitching in one row, up to 118m width. Thus no digitar lenses will work because they have too small image circle. Indeed both my 58mm Schneider 5.6 XL and Rodenstock 150mm Sironar-N 5.6 result in SHARP images. Optimum aperture is at f/11. At f/16 I notice some diffraction begin and wider aperture result in very shallow focus of course.

While the 75mm 4.5 SW Nikkor is indeed suffice sharp for film, diffraction (softness) is obvious when using my digital back because the digital back has higher resolution than the Nikkor lens is capable to resolve (this is a documented problem with e.g. high resolution cameras such as Canon 5DII). My 58mm and 150mm can resolve the resolution of my digital back very well f/5.6-11, but f/11 seem optimum.

Indeed lens fabricators want us to buy digitar lenses with tiny image circles. In my opinion we are over sold by their marketing! I do not want such lens because they do not work for panoramic size I use, and are also $$$. I have found suffice sharpness in SHARP traditional lenses such as my 58mm and 150mm. However, if one search for top Leica like sharpness one needs digitar lens. My 58mm and 150mm are at least as sharp as my Mamiya 645 lenses, except the Mamiya 28mm digital designed lens which is sharper.

It is correct that light rays should preferably be parallel for sensors. However my 58mm is wider than my 75mm Nikkor and I am actually keen on eventually going wider with a 47mm! It depends on what one shoots and what can be accepted in the outer regions of a panorama. I shoot landscapes and do not aim at absolute pixel peeping in widest regions of a panoramic image. For a 75mm lens there seem to be little to no problem but I need a higher resolving lens to complete be sure. With the 58mm there is light fall off in outer regions of a full width panoramic frame. Perhaps that aids to hide any problems due angle of light, not sure yet. Of course, within the center region of a panoramic stitch there will not be a problem also with a wide lens, because light rays are more parallel....

Back to my original question in above original post; which 75mm lens would be optimum in regards to sharpness and thus give me no diffraction at f/11, thus higher resolving than my 75mm Nikkor SW?

Thanks!

Anders

[Eric Leppanen]

Chris Perez and Kerry Thalmann tested one Nikon SW 75mm f/4.5 as part of their LF film lens tests (using TMX B&W film at 1:20 magnification) and noted significantly reduced center resolution at f/11 versus smaller apertures. Rodenstock and Schneider 75mm lenses fared better. See:

http://www.hevanet.com/cperez/testing.html#65mm_thru_125mm

Of course, all of this is based on single samples of each lens type, so YMMV.

[Bob Salomon]

The only choice to do what you want are digital lenses. They don't all have small image circles. The Rodenstock Apo Sironar Digital series have image circles up to 150mm in diameter. They are made specifically for what you are trying to do. Go to the Linos Rodenstock Precision Optical web site and download their white papers on digital optcs and you will get your answers.

[Athiril]

Whats the resolution of the digital system youre using the lens on?

f/11 is the diffraction limit for the Canon 20D, 30D, 5D Mk II etc, anything with a ~6.4 micron resolution.


Hi HK

I have my suspicians. If this lens isn't designed for digital (field flatening for example) then the losses will be quite substandial while not remarkable for a 150mm.

Sensors require light rays to be perpendicular to their face. Angular rays that are off by a few degrees are not recorded or at best partially recorded. That is why all early digital cameras (except Olympus) lost 30% to 40% of their image resolution. Over time, first Olympus, then Sony, then Tamron, and finally the rest realized that field flatening elements were required for effective use of digital optics.

If you add to this that "superwide" lenses were optimized for 1:1 and could not be used effectively for focus distances farther than the hyperfocal distance then horrendous field curvature problems occur.

Lynn

I have to say Olympus lenses are pretty good, I have an old Zuiko prime that fully exceeds a 6.4 micron resolution at f/5.6.

[Anders_HK]

@ Eric,

As I expected, Rodenstock and Schneider 75mm is better than Nikkor 75mm. The 75mm lenses tested appear to have not been the f/4.5-5.6 versions and which my instinct tells me should be even better?


@ Bob,

I much appreciate your knowledge. What I look for is still sharp traditional 75mm lenses. How do the Rodenstock older and newer such compare to the Schneiders? - example to this one http://www.kenrockwell.com/schneider/75superangulon.htm

Further, www.linos.com/pages/no_cache/home/shop-optik/rodenstock-foto-objektive/digitale-fachfotografie/?sid=13372&cHash=e83207df0f#sid13372 state the lenses you suggested are recommended for up to 72x96mm and there is no 75mm such. Thus they are out for my up to 44x118mm stitches. I also use my lenses for 4x5 film, thus digitars are out of question due to too small image circle. My Rodenstock Sironar-N is excellent, very sharp also for my Aptus 65 and cost me only 400 usd on Ebay. :)

Anders

[Bob Salomon]

@I much appreciate your knowledge. What I look for is still sharp traditional 75mm lenses. How do the Rodenstock older and newer such compare to the Schneiders? - example to this one http://www.kenrockwell.com/schneider/75superangulon.htm

Just as well with most and surpass them with others

[Further, state the lenses you suggested are recommended for up to 72x96mm and there is no 75mm such. Thus they are out for my up to 44x118mm stitches. I also use my lenses for 4x5 film, thus digitars are out of question due to too small image circle. My Rodenstock Sironar-N is excellent, very sharp also for my Aptus 65 and cost me only 400 usd on Ebay. :)

Anders
The 70mm Apo Sironar Digital covers a 125mm circle.
Unfortunately you have the requirements of a digital lens and the budget for a used lens. In that case you will not be able to solve your problem with analog lenses.

I can't give you the Digitar image circles as we are not involved with them. But Rodenstock does make digital lenses with large enough image circles for what you need. They also make digital lenses with image circles too small for your needs. Why don't you contact a dealer and rent a couple to see what they can do? Or at least visit a dealer with a demo studio to see the performance gains?

[Anders_HK]

The 70mm Apo Sironar Digital covers a 125mm circle.
Unfortunately you have the requirements of a digital lens and the budget for a used lens. In that case you will not be able to solve your problem with analog lenses.

I can't give you the Digitar image circles as we are not involved with them. But Rodenstock does make digital lenses with large enough image circles for what you need. They also make digital lenses with image circles too small for your needs. Why don't you contact a dealer and rent a couple to see what they can do? Or at least visit a dealer with a demo studio to see the performance gains?

Bob, in all respect and in repeat, I do not need or want a digitar lens. Period. I have stated above that per what I experience traditional SHARP large format lenses works just very fine for my digital back. Then why do you insist on pointing me towards what I really do not need, want and what is $$$???? The 70mm is not 75mm which is the focal I want, nor is 125mm suffice with lens movements for my stitching, nor for 4x5! I have done suffice explaining above.

The lenses I have asked about in my original post top above cost 500-900 usd used. I am interested in which one of them is sharpest and highest resolving. Again, I much appreciate if you have any such info of how your (Rodenstock) TRADITIONAL non digitar SHARP lenses compare to Schneiders such?

My camera is a Shen-Hao TFC-45B which apparant works just fine, no need for $$$ digitar tech camera. My digitar sliding adapter is a custom design made per my design in China which was cheaper than most on market. It works per my test shooting too. Simply, I reasonably know what I am doing... but if someone is pixel peeping far ends on my really wide stitches may not like it, but with the photos I am happy camper!

Anders

[Bob Salomon]

"The lenses I have asked about in my original post top above cost 500-900 usd used. I am interested in which one of them is sharpest and highest resolving. Again, I much appreciate if you have any such info of how your (Rodenstock) TRADITIONAL non digitar SHARP lenses compare to Schneiders such?"

Anders, no film lens will meet the resolution, distortion, diffraction of a digital lens. Again, download Rodenstock's white papers on digital lenses and read them.

[Larry Menzin]

I've had decent results shooting a 75mm 4.5 Rodenstock Grandagon-N with my Phase digital back. You will need to do a lens cast calibration adjustment if stitching with that lens.

[Anders_HK]

I've had decent results shooting a 75mm 4.5 Rodenstock Grandagon-N with my Phase digital back. You will need to do a lens cast calibration adjustment if stitching with that lens.

@ Larry,

Much thanks for info! You know what I speak of. Which P1? The lens cast calibration adjustment is for the widest of stitched frame, yes? Thanks!


@ Bob,

I have already stated clear: Non digitar lenses works fine. You are trying sell me something I not want or need. I do not want digitar. Please respect.


Regards
Anders

[Bob Salomon]

@@ Bob,

I have already stated clear: Non digitar lenses works fine. You are trying sell me something I not want or need. I do not want digitar. Please respect.



Anders, again, I don't have any connection with Schneider Digitar lenses and would not try to sell you one. I represent Rodenstock and have suggested that you read the white papers they printed or go test at a dealer. You will not get the results you want from an analog lens. That is why digital lenses were developed in the first place.

To make it clear, Digitar is a Schneider brand name. It is not the name of the type of lens. For Rodenstock it is Apo Sironar Digital and Apo Sironar Digital HR and their new names HR Digaron S and HR Digiron W.

Schneider calls theirs Digitars.

[Anders_HK]

Anders, again, I don't have any connection with Schneider Digitar lenses and would not try to sell you one. I represent Rodenstock and have suggested that you read the white papers they printed or go test at a dealer. You will not get the results you want from an analog lens. That is why digital lenses were developed in the first place.

To make it clear, Digitar is a Schneider brand name. It is not the name of the type of lens. For Rodenstock it is Apo Sironar Digital and Apo Sironar Digital HR and their new names HR Digaron S and HR Digiron W.

Schneider calls theirs Digitars.

Bob,

My apology, in above I referred by "digitar" to also Rodenstock digital large format lenses. My interest is in NON digital large format 75mm lens. Contrary to your assumption of what I want from lenses, as I stated above I am happy with both my Schneider 58mm SA and Rodenstock Sironar-N 150 / 5.6 NON digitar/digital lenses. Non digitar/digital large format lenses are fine for my digital back if SHARP, but yes digitar/digital are sharper yes, but I find sharp non digitar/digital suffice, the rest is marketing hype, also the white paper that I read already the other year. What I look for is a 75mm SHARP & HIGH RESOLVING traditional 75mm lens - non digital lens.

I have made many posts to clarify this. My original post seem to ask exactly for same. If you have such info as I ask I appreciate. Allow me to again make clear: I seek no info of digitar/digital large format lenses.

As for digitar/digital lenses, personally I think both Rodenstock and Schneider should have made them 4x5 image circles and similar priced to traditional... but that is my opinion. Yet perhaps consider...

Anders

[Anders_HK]

deleted, double post

[Anders_HK]

Any advise of 4x5 lens for me???

Thanks :)

[dwhistance]

Anders,

If you are going to buy secondhand I suspect that the sample to sample variation in individual lenses (as a result of how they have been used/kept) is going to be greater than the theoretical differences between different manufacturers lenses of the same focal length/type. As a result I suspect the only realistic approach to take is to try and get hold of a number of lenses, test them, and then keep the sharpest.

As far as individal lens recommendations go have you tried a Super Symmar XL 80mm (assuming that you would be happy with 80mm v 75mm)? I've used mine with 4x5 film and with a Betterlight digital back and have been very happy with it. Mine is very, very sharp and the coverage is good, better I believe than most 75mm lenses. Just to highlight my point above, I know that others have had bad experiences with this lens indicating that again sample to sample variations can be large enough to make a noticeable difference.

David Whistance

[Anders_HK]

Anders,

If you are going to buy secondhand I suspect that the sample to sample variation in individual lenses (as a result of how they have been used/kept) is going to be greater than the theoretical differences between different manufacturers lenses of the same focal length/type. As a result I suspect the only realistic approach to take is to try and get hold of a number of lenses, test them, and then keep the sharpest.

As far as individal lens recommendations go have you tried a Super Symmar XL 80mm (assuming that you would be happy with 80mm v 75mm)? I've used mine with 4x5 film and with a Betterlight digital back and have been very happy with it. Mine is very, very sharp and the coverage is good, better I believe than most 75mm lenses. Just to highlight my point above, I know that others have had bad experiences with this lens indicating that again sample to sample variations can be large enough to make a noticeable difference.

David Whistance

David/Anyone,

Very interesting reply. Thanks! Which Betterlight scanning back do you use, thus so I can compare resolution of it compared to my Aptus 65?

Frank, 80mm will be about equal to 24mm and is not suffice wide for me. On other hand, I was just reading more of the "same new era" 72mm XL, which unfortunate is @520g, large and costs $$$. Or, could it be that I could go with its predecessor that is 75mm, and is that one perhaps/perhaps not just as sharp for my specific purpose? Any guess?

What about the 75 Super Angulon MC/non MC around 1970, but... for my purpose is it still as good as the "new era" ones? http://www.kenrockwell.com/schneider/75superangulon.htm - for 4x5 indeed good, but for my purpose??? As you say... the sample variation may be larger depending on how they been kept/used. That is a very much valid point! Yet again a stellar copy of those might be better than one that is slight less condition but of the newer, or?

Alternatively, my thought go to the Grandagon-N. Then, there is the question of what is difference between the one with and without the green stripe on lens barrel, and if makes any difference to me...

Was it Schneider or Rodenstock that developed their wide optics to newer "standards"/optimized it first, and around what time?

Above indeed many thoughts and questions, but a very kind thanks to you and all/anyone for further reply.

Anders :)

[Anders_HK]

I should add; my Rodenstock 150mm 5.6 Sironar-N seem plenty sharp (albeit less than digital/digitar, as I assume). Interesting was I had an older Chinese gentleman I hold trust for clean it in Shanghai, and he showed me his cotton budds after cleaning, pointing out how dirty it was. He used TEA on cotton budds to clean it! - Real. :D

If dust, I assume no problem, but... any other blemishes would be detrimental... right, or? One never knows... :p

Thanks :)

Anders

[Anders_HK]

Email reply from Schneider-Kreuznach

Me - "... what are the actual differences on following Schneider lenses in regards to my use. I am seeking a lens that has a suffice high resolving power and much better such than my Nikkor 75 SW 4.5.
- Schneider 75mm Super-Angulon 5.6, e.g.?http://www.kenrockwell.com/schneider/75superangulon.htm
- Schneider 75mm Super-Angulon MC 5.6
- Schneider 75mm Super-Angulon XL 5.6"

S-K - "The only lens we would like to recommend is our Super-Angulon XL 5,6/72mm which is an superb wide-angle lens with excellent resolution."

Me - "1. What was optically improved with the 72 XL compared to its predecessor 75mm SA 5.6?
2. Do you have info on how the 72 XL compares to the optical quality of the Rodenstock 75 Grandagon-N (green stripe) 4.5?"

S-K - "the 72mm lens is a complete new design and calculation and in comparison to the older calculations of Schneider 75mm lens as also Rodenstock 75mm lens the resolution is higher and the color separation in the width is much smaller."

Me - "How is the 72 compare to your 80 XL?"

S-K - "it’s a different design.
The XL aspheric design was made for field photographers and gives the quality of a standard taking lens and coverage of a wide angle lens, but both moderate.
If you are going for a wide angle lens with best performance and best resolution with minimum distortion you should use the 72mm lens.
If you are looking for general purpose the 80mm is more convenient for you."

Seems 72mm is the choice, I ordered mine.