Lens testing

Bill Pierce

Bill Pierce

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Many years ago I was having lunch in the Leitz cafeteria in Wetzlar with one of the gentleman who tested lenses, both theirs and the competitions. The test lab facilities were impressive. On the wall of the cafeteria was a board of printed pictures and fellow lunchers inspected the images and expressed their opinions. I said that If this evaluation was also a test of the lenses, it was much less impressive than the lab tests.

It was then that the Leitz employee, as politely as possible, reminded me that I was an idiot. While lab tests provide information on the overall performance of a lens, more important to a maker of lenses, they show very specific optical problems to be corrected within a design. The designer needs to know the lens has a problem with spherical aberration. We photographers have to know that the lens has problems with landscapes and architecture, but has a certain charming glow when used to take pictures of lovely women.

So my lens tests now consist of taking a lot of pictures - landscapes, portraits, distant shots, medium shots close up shots, wide-open shots and stopped down shots. Of course I’m not just testing the lens. I’m testing the lens/camera/my usage along with the print making process. It wouldn’t be a very good test if I was designing lenses, but I’m taking pictures. Admittedly, in the test period I’m taking a lot of pictures that are not very inspiring and then spending a lot of time looking at pictures I wouldn’t normally print. But, it’s worthwhile. I have actually gotten to know which of my lenses work for me. A few have been banished; some have been raised to stellar status. Lens testing - incredibly boring and very worthwhile…

Your thoughts?
 
It's one of those things where a star rating system has little value... the old adage about knowing your equipment. I find that I learn to love or come to appreciate this or that over time, whereas if I judge a lens (kit / process) that combination may end up on the back burner... sometimes to reemerge sometimes to languish, almost never sold as some juxta of events may be align. But I do admit to having favorites... and need to re-visit the back of the cabinet.
 
My way of testing is to go out and use the lens. Lens designers have done the heavy work for us. Everything is good these days but not everything is appropriate for everyone.
 
If I want to know about lens I do this - lens name flickr - in Google search line.
It brings me group for this lens. Usually it has thousands of photos.
This is how I learn about the lens optics in general and broad view.
I also read photozone and many other reviews. To find out how lens is build, size, weight and so on.
I also google it - lens name rangefinderforum.com - and it brings even more. I credit this source highly.

And then lens comes I do test shots to see if focus is within accurate range (focus chart) and take brick wall picture to test if lens is not de-centered.
Maybe one shot in the sky with leafs to see purple fringing and one into the sun for flaring.

Then Bill's route.
With one thing to mention. I like to get lens on film body and have negatives to print from. This tells me if I want to keep lens or just keep it for awhile. Ideally I like to have lens for digital and bw film. So far I have one which does it great on both media.
Summarit 35 2.5. Others will do digital and fail on film. Or fine on film, but kind of special on digital.
For example. My Cron 50 v4 is way to neutral, just sharp lens on bw prints, but sweet on digital. It is OK in handling. My Planar 50 ZM was flat and green on digital. Difficult to work with aperture ring. Ultron 50 1.5 ZM was great on BW prints and OK on digital. Strange focus ring and keep unscrewing hood.

By now I'm little bit tired. I tested many less expensive than Summarit-M lenses the way I described... I just want lens I could work with. And to find lens which will be adequate to Summarit-M 35 2.5 is mission impossible it seem. To have manageable size, pleasing rendering on film, no funky goo on digital and to be smooth and pleasing in handling.
 
I do not test lenses, I use them! I'm not a pixel peeper and if the results I get from a lens satisfies my "vision" the lens is ok...

I recently bought the Summaron 28/5.6 because very curious about it and also desiring to change my photo style. The lens stayed on the M10 three months, during which I used it in many different situation. I even like to use it in interior with available light (Yes, I know it's 5.6...). Now that lens is on my M7 to see how it works with film.

I never gave a look at MTF charts or similar test for this lens. And now I can say I'm satisfied, I'll keep and use it for a long time...

robert

PS: but I have to say that for me photography is more emotion than technology 🙂
 
In the early 2000's I worked as a camera tech in the motion picture industry. One rental company I worked for had a really nice projecting collimator that we used to test all the rental lenses. It was really impressive and fun to use, and was good at telling us when a lens came back with a problem. But it told us little about how a lens renders.

I think lens rendering is a very 'personal taste' thing. I've had lenses that others have sworn by that just don't work for me. And I've had lenses that others consider garbage whose rendering I really like. So I keep the ones I like and sell the others.

Currently working on a project that I'm shooting with lenses from the 1940's-1950's. After doing a CLA on each I've been testing them extensively with a digital body (because it's quick and easy), and the ones that don't have 'problems' on the digital, then get tested with a film body (the project is being shot on film). And again, then it's down to personal taste, if they render in a way I like, I keep them. If not, they get sold.

Best,
-Tim
 
Ko.Fe. said:
If I want to know about lens I do this - lens name flickr - in Google search line.
It brings me group for this lens. Usually it has thousands of photos.
This is how I learn about the lens optics in general and broad view.
Click to expand...
Small compressed jpgs with a resolution of 72ppi for lens tests? What could you possibly learn?
 
ptpdprinter said:
Small compressed jpgs with a resolution of 72ppi for lens tests? What could you possibly learn?
Click to expand...

You must have been using different Flickr then. 🙂 Where are many full resolution scans and full sized digital files for every lens I have explored. Scans are irrelevant to me, but full sized digital files are interesting to look at.


Also, it is not lens tests files, it is replacement for Bill's test to see how lens regularly works in non-test real life environment.
Small size images still shows you lens bokeh, flaring and so on. Personally, I'm able to see it on regular Flickr screen.

I'm with Robert and Bill on lens test. I keep lens for couple of months at least and use it as much and as often as possible to see if lens passes in use test (after on charts and bricks test 🙂 ).
 
Ko.Fe. said:
I'm with Robert and Bill on lens test. I keep lens for couple of months at least and use it as much and as often as possible to see if lens passes in use test (after on charts and bricks test 🙂 ).
Click to expand...
I'm not a lens hopper. I have had most of my lenses for decades.
 
As said above numerous times - if it gives me the results I want, it's a good lens for me. It may not suit everybody, but I don't buy for them. I use, and enjoy, a number of 'bad' lenses including one that's regularly trashed on the Leica forums - the 135 2.8. Heavy and a bit cumbersome, but it produces results that even the newer 135 lenses can't.
 
presspass said:
As said above numerous times - if it gives me the results I want, it's a good lens for me. It may not suit everybody, but I don't buy for them. I use, and enjoy, a number of 'bad' lenses including one that's regularly trashed on the Leica forums - the 135 2.8. Heavy and a bit cumbersome, but it produces results that even the newer 135 lenses can't.
Click to expand...

These days I use longer lenses on cameras that focus through the lens. Just wanted to add that in my all rangefinder, pre TTL days I used that lens for news and studio portraiture - and it delivered.
 
Hi Bill;

I test my lenses.

Years ago, when picking up all my Nikon gear from it's annual cleaning, a Nikon Factory Tech came out of the repair area holding my 24mm f 2.8 AIS. He was accompanied by a translator. He wanted to know where I got the lens. I didn't specifically remember, but told him it came from one of a couple of camera stores where I shopped. I asked why he wanted to know. He said, it was the sharpest 24 2.8 he had ever tested. It was a lens I used often indoors in tight spaces and felt very lucky to have gotten a good one, by accident.

I'm not big on owning a lot of camera gear. But, paying the bills with the stuff, I've had a bunch. My most used FLs are 35 & 50, actually, a 55micro 2.8 in the past and now a 60 2.8 Nikkor AF. In shopping for (and buying) a number of 55mm Micros, I found a great variance in quality between, extremely good and visibly outstanding. It took 5 tested lenses to isolate the winner. I found it early in the testing and subsequent lenses failed to best it.
Working with small film (Kodachrome) was often looked down on by Ad agencies even in the 80s and 90s, depending on the subject matter. My stuff had to be sharp.

Today, with zooms and some primes, the QC isn't as good as it might be?? Maybe these fragile optics are injured in shipping or handling ? I don't know. But, i test everything. My gear is well cared for but, things happen. An assistant banging a lens by accident won't get him/her fired, but, not telling me about it will. I test after any mishap. I've dropped lenses. Only a few inches, but on to concrete (DR Summicron). It happens, and, i won't use the lens until it's well tested by me and my repairman, even if the lens shows no visible damage.

pkr
 
back alley said:
what would a standard testing at home look like?
Click to expand...

I start with sheets of newspaper taped to a wall. They are lit at 45 degrees by quarts light. The camera is tripod mounted and a cable release is used. I test at several camera to target distances at all aperture settings. The lenses that do well, are taken outdoors for testing at further distances and for their color personality. A lenses' color personality has to do with my taste. I'm not big on post production. I prefer good looking files out of the camera. I don't shoot RAW as often as I once did.

I test with both AF and Manual Focus settings. I often work in MF with wide lenses. I don't often use focal lengths longer than 105 (FX/FF). I prefer primes to zooms, but test and use both.

I once owned a 17-35 f 2.8 Nikkor. It was very sharp at 35mm. At other FLs it was horrible. It was a very heavy lens. I sold it months after testing it. Maybe I got a bad one? But, unless it had done well through the range, i wasn't willing to pack it around.
https://imaging.nikon.com/lineup/lens/f-mount/zoom/widezoom/af-s_zoom17-35mmf_28d_if/index.htm

Bill is right, it's really boring work. I usually do it in one hour bits, with a glass of wine and my note book. The results can be eye opening. I'm often surprised at the findings. Save your lens boxes and packaging, it makes selling the failures easier.
 
ptpdprinter said:
I have had most of my lenses for decades.
Click to expand...

If you want to measure it in decades...
I had only three cameras with single lens attached to them from late seventies to the end of 2009. I still have and using first camera, lens. Second camera has broken AF in build-in lens and it was replaced by third camera, which I used yesterday.
 
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