Test Pattern for Variety Lens Testing

[Tin Can]

I will be inside almost all winter. My winter project is to test my Large Format lenses

AND

See if I can actually manually focus sharply with my old eyes!

This website seems to have good ideas, I will inkjet print his target #2, mount them as he describes on what he describes with the alignment tool

I don't care about color at all, so only B&W, testing will be with actual film, using one studio camera, Old and heavy duty Linhof Color Kardan as it can shoot 4X5, 5X7, 8X10 with barrel or shuttered lenses having good stability and alignment. Strobes will be used.

For short lenses I will decide later...perhaps a Norma

any ideas to add?

Targets?

Best film to use?

[Bob Salomon]

Why?

Will you be using your lenses to shoot newspapers plastered flat on a wall or will you shoot people, places and things?
Will you use your lenses at near distances or far?

Will you do your tests all at the same time, with the same lighting, at the same exposures, on the same emulsion, developed all at the same time in chemistry that is equally fresh, will you use the same loupe to test under the same lighting when looking at the results, with your eyes equally fresh?

If not you are simply wasting time, film and chemistry.

Lenses should be tested under the conditions that you will use them for and on the types of subjects that you will be shooting.

[Tin Can]

Good points Bob!

As I age, I am doing far more shooting inside my studio than outside

I do use the same chems all the time, with standardised gas burst

I most likely will use Ilford FP+

I want to know if MY well used lenses, bought used and from various dubious sources, are good or bad, many could be junk!

I also want to see if I can focus anything at all...maybe not!

That result will end testing quickly

Yet I seldom give up...

[Greg]

RE: my post, it's the second one
https://www.largeformatphotography.i...t=lens+testing
My favorite lens that I have use on my 8x10 since the 1970s does terrible at resolving the type of a newspaper.

[ic-racer]

Testing at less than infinity will likely be testing flatness of field and your camera settings. Unless your lenses are factory duds or messed up by tinkering hands, the tests will show how close your ground glass is to the T-distance of your holders and how parallel you have your film back to lens optical axis to target and how curved the image plane might be at less-than infinity. These are all good things to test but most does not relate to the lens at all.

[Tin Can]

I also forget things!

First i try lenses made to be SHARP, then SF

This is a hobby for me, I never sell any picture

I have made some 'good enough' portraits

11X14 on HP 5 Nikon 610 with SC11 3 years ago, sloppy scan, a lot of eye surgery since then, tomorrow I see the Doc again...never good news....

Kurk 11X14 HP5 by TIN CAN COLLEGE, on Flickr

RE: my post, it's the second one
https://www.largeformatphotography.i...t=lens+testing
My favorite lens that I have use on my 8x10 since the 1970s does terrible at resolving the type of a newspaper.

[ic-racer]

I also saw a thread on APUG about 'what to do in the winter' but my best work (or only good work at all) comes in the winter...

[Jim Jones]

Why?

Will you be using your lenses to shoot newspapers plastered flat on a wall or will you shoot people, places and things?
Will you use your lenses at near distances or far?

Will you do your tests all at the same time, with the same lighting, at the same exposures, on the same emulsion, developed all at the same time in chemistry that is equally fresh, will you use the same loupe to test under the same lighting when looking at the results, with your eyes equally fresh?

If not you are simply wasting time, film and chemistry.

Lenses should be tested under the conditions that you will use them for and on the types of subjects that you will be shooting.

Bob makes good points, although lens test charts are valuable for numerically comparing various lenses. The old standard USAF 1951 lens resolution test chart has the advantage of availability and wide use. One site from which it can be downloaded is http://www.takinami.com/yoshihiko/ph..._test/USAF.pdf. This version is not perfect at the finest resolutions, but good enough for practical use. It should be saved and printed out in bitmap or GIF format, not as the JPEG that some other sources provide. Instructions for using this chart are widely available online. Some are basic, some rather detailed.

[Tin Can]

Thanks Jim, I will see what Walgreens can produce from the file.

Bob makes good points, although lens test charts are valuable for numerically comparing various lenses. The old standard USAF 1951 lens resolution test chart has the advantage of availability and wide use. One site from which it can be downloaded is http://www.takinami.com/yoshihiko/ph..._test/USAF.pdf. This version is not perfect at the finest resolutions, but good enough for practical use. It should be saved and printed out in bitmap or GIF format, not as the JPEG that some other sources provide. Instructions for using this chart are widely available online. Some are basic, some rather detailed.

A few days ago I was just starting to think about how to do what I want. Here is a first attempt. Selfie, focused by trying to align the Spam can with my eyes, then decided I was off so shut my eyes.

Shot in full dark, strobes, no shutter. Ektascan 8X10 in Trays Rodinal 1/100 7 minutes

Lens, Gundlach Manhattan Company Achromatic Meniscus F6 Portrait 161/2" #117553 wide open

Here is an old thread where the usual suspects discuss the lens. https://www.largeformatphotography.i...l=1#post170873

SpamFirst try selfies by TIN CAN COLLEGE, on Flickr

[Arne Croell]

Have a look at these: http://www.normankoren.com/Tutorials/MTF5.html. That's what I used for my tests (http://www.arnecroell.com/lenstests.pdf)
I printed out 7 of them and arranged them in the center, two corners, and intermediate position of the test target, in sagittal and tangential orientations (except for the center). They do have a "hard" b/w part which is the equivalent of the USAAF chart, but the 50%MTF and 10%MTF patterns give you more realistic information.