lens resolution numbers

[FrankS]

Tried searching the net but can't find lens resolution numbers for typical 135 format 50 and 85mm lenses. (The Hasselblad 80f2.8 Planar resolves about 68 line pairs per mm in the center.) Does anyoe know or can point me to a site that gives this info?

 

[Freakscene]

Resolution cut-offs aren't used very often because they aren't very helpful in describing performance; lens performance is usually measured in % response at specified frequencies - this measurement, called modulation transfer function (MTF) is the normal way to describe a lens' resolution. There's a nice introduction to MTF here:
http://www.luminous-landscape.com/tutorials/understanding-series/lens-contrast.shtml

Marty

 

[ZeissFan]

Popular Photography used to have this kind of information, right?

And I guess you would have to look at a lot of lenses, unless you're looking for specific lenses.

I'm not sure what "typical" lenses would be. Rangefinder? SLR? Canon, Nikon, Pentax, Leica, Zeiss, Olympus, Vivitar?

 

[FrankS]

Would you say that a 135 format lens typically resolves better than a comparable typical medium format lens?

I have the opinion that the smaller image circle of the 135 format means that the lens elements can be smaller than a comparable MF lens, and that therefore it is easier to design and build a 135 format lens with higher resolution capabilities than a comparable MF lens.

 

[venchka]

http://www.hevanet.com/cperez/MF_testing.html

http://www.hevanet.com/cperez/testing.html

I think Brian Sweeney posted some JPEG copies of lens tests from the 70s. Ask him where he posted them here can't RFF. I can't find them. They may have been posted by someone else, but I know they were here. I owned 3 lenses in the report.

 

[Sonnar Brian]

The 1976 Pop Photo tests listed percent contrast for 50lp/mm targets.

The image projected by a lens can be described in a lot of ways, resolution, contrast, distortion, etc. The only one that counts for photographic purposes- do you like the image that it makes?

 

[FrankS]

What's your take on my post #5, Brian? Agree or no?

 

[FrozenInTime]

From Zeiss Camera Lens News #2 http://www.zeiss.com/cln
( click on archive to get to the list of old issues : don't you just hate websites that don't direct link 🙁 )

Objects of 4 millimeter in size (approximately 1/6 of an inch) have been imaged from almost 400 meters distance (more than 1.000 feet) with a 100 mm Carl Zeiss Makro-Planar lens at f/5.6 and a Contax RTS III 35 mm SLR camera featuring the unique Contax vacuum pressure plate. Similar results were obtained with Contax AX 35 mm autofocus SLR, Contax RX 35 mm low noise SLR and Makro-Planar 60 mm, Planar 85 mm f/1.2, Planar 100 mm f/2, Aposonnar 200 mm f/2, Vario-Sonnar 28–85 mm and 35–70 mm zoom lenses, even with moderate priced Planar 50 mm and Distagon 28 mm.

Resolutions on the same level have been achieved with Carl Zeiss lenses in Hasselblad medium format cameras, proving that at Carl Zeiss, medium format lenses, contrary to popular belief, offer no lower resolution than the very best 35 mm lenses.

 

[FrankS]

From Zeiss Camera Lens News #2 http://www.zeiss.com/cln

Objects of 4 millimeter in size (approximately 1/6 of an inch) have been imaged from almost 400 meters distance (more than 1.000 feet) with a 100 mm Carl Zeiss Makro-Planar lens at f/5.6 and a Contax RTS III 35 mm SLR camera featuring the unique Contax vacuum pressure plate. Similar results were obtained with Contax AX 35 mm autofocus SLR, Contax RX 35 mm low noise SLR and Makro-Planar 60 mm, Planar 85 mm f/1.2, Planar 100 mm f/2, Aposonnar 200 mm f/2, Vario-Sonnar 28–85 mm and 35–70 mm zoom lenses, even with moderate priced Planar 50 mm and Distagon 28 mm.

Resolutions on the same level have been achieved with Carl Zeiss lenses in Hasselblad medium format cameras, proving that at Carl Zeiss, medium format lenses, contrary to popular belief, offer no lower resolution than the very best 35 mm lenses.

Thank you for that info!

 

[tlitody]

All pretty irrelevant if you are hand holding the camera. You might think it's still but it isn't as still as it could be. And very importantly you have to understand resolution and contrast.

The big numbers given are usually at 1000:1 contrast which means line pairs where alternating lines are 11 stops different in brightness. Thats a fairly unlikely situation in the real world (except white picket fences at 400m). The much lower figures are more representative. Fuji give two contrast ratios on their film datasheets. 1000:1 and 1.6:1 the lower contrast ratio reduces lppm from 160 on provia 100 down to 80 lpmm. 1.6:1 is far closer to real world contrast in many subjects except where you have edges of light colours against dark colours and where the light colours are in strong light. But that only gives you high resolution at the edge.
Fact is that a good quality lens such as zeiss or leica can resolve more detail than most film can capture (depending on subject contrast ratio). Its the lighting on the subject and colour contrast in the subject which is the real determing factor of final resolution on film and not the lens or film. But put your camera on a tripod and pick your subjects well with strong side lighting and you can achieve very high resolution in film from a 35mm camera.
Oh, and measuring line pairs per millimeter isn't the same as being able to perceive detail in an image (so I'm told).

 

[Sonnar Brian]

Frank- I think a poor lens looks better on large format because you do not have to enlarge the image as much to get a decent sized print.

I have a couple of lenses that are the same optics used on different format cameras. An Arriflex Sonnar 5cm F1.5 has the same front element and front triplet as a 35mm full-frame lens, the rear triplet is "truncated". Same with some Nikkor lenses on a Bronica: the 13.5cm F3.5 comes to mind.

 

[mfogiel]

Frank,
The general rule definitely is, that the smaller the image circle, the easier it is to obtain higher resolution. In fact, even the incredibly well corrected apo lenses for LF made today, cannot match the resolution of MF or 135 format lenses, if they have to cover a large image circle. Conversely, some of the best resolving lenses now, are o be found among the modern view camera lenses made for the digital sensors, which cover a notoriously small image area. I have read somewhere, that the goldilocks of the relationship between resolution and image circle is to be found in the MF - this is probably all the more the case now, if you use the digital backs.