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 (http://www.bobatkins.com/photography/technical/lens_sharpness.html) 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 (https://www.largeformatphotography.info/forum/showthread.php?129708-Linhof-Kardan-8x10-How-to-mount-lens&p=1320656&viewfull=1#post1320656) 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.info/forum/showthread.php?155445-Easy-Testing-Used-LF-Lenses&highlight=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....

https://live.staticflickr.com/653/32121286461_a8037c002c_b.jpg (https://flic.kr/p/QWrZnP)Kurk 11X14 HP5 (https://flic.kr/p/QWrZnP) by TIN CAN COLLEGE (https://www.flickr.com/photos/tincancollege/), on Flickr




RE: my post, it's the second one
https://www.largeformatphotography.info/forum/showthread.php?155445-Easy-Testing-Used-LF-Lenses&highlight=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...
198551
198552

[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/photo/lens_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/photo/lens_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.info/forum/showthread.php?18733-16-1-2-Gundlach-Achromatic-Meniscus-Portrait-lens&p=170873&viewfull=1#post170873

https://live.staticflickr.com/65535/49239062033_6227e2efb3_b.jpg (https://flic.kr/p/2i264Fp)SpamFirst try selfies (https://flic.kr/p/2i264Fp) by TIN CAN COLLEGE (https://www.flickr.com/photos/tincancollege/), 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.

[Tin Can]

Arne, thanks for the link. I skimmed it and will read more closely soon

I just got in the door from buying white pegboard and picking up Bob Atkins printed targets. I'll look at them tomorrow as my eyes were just tortured by Optometrist.

My 'plan' is to compare similar focal length lenses, making the target fill 11X14, 8X10, 5X7, 4x5, 3x4, 2x3 sheet film as appropriate.

I think switching to Tmax 100 is a good idea for 8X10 and under. As I have only 11X14 Tmax 400, I will use it because it's paid for. I will first experiment with Ektascan X-Ray in all sizes.

This is personal winter work and may not be submitted to our sharpshooters here. I use that term in the 'Monday morning quarterback' sense. You are not one of them.

Thank you, Arne!

[John Kasaian]

For targets, I've had fun shooting a huge, say 20 acre+/- college campus parking lot from an elevation that can record all the rear license plates. With a 9x loupe see which is the farthest license plate you can read

[pgk]

For may years Amateur Photographer magazine (Geoffrey Crawley?) used to shot photos of a sailing ship on the Thames as a 'real world test' of any/all lenses reviewed by the magazine, I assume on the basis that this told most users how they would perform as frequently used. The problem with any sort of testing is that it only supplies information about how a lens performs under the test conditions. To be meaningful, tests need to be orientated towards checking the performance of lenses under the conditions in which they are to be used. Subjectivity then comes into play. I've 'tested' lots of lenses over the years - from MTF bench to in the field - and I now simply use lenses and if I don't like the results for my subject matter, I move on. There are times when high resolution is of importance but in all honesty its not as necessary as many would have us believe - I have 30" x 20" fine art prints off an 18MPixel camera which sell, equally I have much smaller prints which also sell. Content almost always is of far greater import than absolute resolution (caveat: my background is in photographic science where precise imaging IS often important, but then lenses are often designed for very specific uses if precision is an absolute must).

[Tin Can]

I mostly shoot in studio, as for years I was incapacitated. I now can get out in the real world, but must be careful with cold weather.

Winter work for me is inside, so testing my gear inside seems correct for me.

Today I am working on my target, which I am adapting in a few ways. I will make it tiltable to allow indoor DOF testing both front and behind imaginary eyes.

A laser cross beam level can be attached by superclamp to the monorail, allowing for better alignment when combined with distance laser. Heretofore I was using DOF tables, this will give me real world visual experience.

I worked in scientific test labs most of my life and love setting up experiments and conducting them in real time.

When it warms, I will move to photographing power lines despite my lesser interest in them...

I was a sailor, and haven't seen a sailboat in this area. Love wood boats.

John, I will not take camera gear to a high vantage point on a college campus to photograph parking lots. My goal may be dangerously misinterpreted. Here the tallest buildings are the dorms full of students. Now one to a room. 50 years ago I was a student janitor cleaning them for $1.40 per hour. They all seem depressed as now enrollment is 50% of our era.

I do walk around the lovely campus, but am forced to park a mile away. Next summer I may tow my big camera on a bicycle trailer.

Here is calculated DOF studio shot, which includes the camera I use most, a portrait I shot with it, DIY rowboat, DIY Dragons, my fake model and a large clock set to '2 Minutes to Midnight', which is the title of the image.

I spent a lot of time on this 'Still Life', nobody 'Likes' it. But that was not the point...the clock is ticking...

https://live.staticflickr.com/7802/47492097241_a3631af543_h.jpg (https://flic.kr/p/2fmHpUM)2 min 360 2019-03-24-0001 (https://flic.kr/p/2fmHpUM) by TIN CAN COLLEGE (https://www.flickr.com/photos/tincancollege/), on Flickr