I have a two part question - and probably something that has been thrashed to death before so excuse my ignorance please.
Firstly, how do people do their own lens tests? I have read somewhere about putting a sheet of newspaper on the wall and shooting at all apetures - is this how it is done? Or do people prefer to test out in the field?
Also, do you shoot 100asa slide to test the lens, or print film - (given the inconsistancy of print processing I'm guessing slide)?
In lens 'tests' the word "soft" will often be used, especially when talking about a lens wide open. Is this softness a perceptable thing in 8x10 enlargements, or more of a scale thing that you would have to be a scientist to appreciate and identify?
The reason I ask is because I am at the stage of A: wanting to test my Nikkor 70-210 4.5/5.6 which I'm not sure is all that "sharp" - and also B: looking to purchase another lens in the 28-80 zoom area.
For the price, lenses like Sigma's 28-70 f2.8 and Tokina's 28-80 f2.8 look very attractive (I haven't got a huge budget, and am going to have to save for a while to get it anyway). But owning a Nikon, I would of course rather get a Nikkor for it - but the money is a factor (I can't really aford a Nikkor 2.8, even second-hand) and would have to start looking instead at the Nikkor 28-105 3.5/4.5 - foregoing the 2.8 fstop.
But then there are those lens test again that talk about "softness" in the sigma's and tokina's, and that scares the hell out of me. Does anyone have any experience with these lenses (or other sigma's, tokina's, tamron's etc).
Does anybody test their lenses before they buy?
Sorry about all the questions, but this whole lens question gets me uptight - especially since it's the lens that determines image quality (yeah, I know - buy the most expensive one you can afford - right)? But how good are Sigma's etc... if that is what I can afford?
Originally Posted by Wayne Lorimer
Start with that then I'll give my opinion which is worth about 2cents less then you'll pay for it.
If you're going to test test the same way you'll use the lens. If you're going to use the lens with slide film then test it with slide film. If you're going to photograph test charts then test with them-) Unless you're looking for numerical numbers I'm not really sure why so many people test with test charts. I'm not talking about people trying to collect data to compare lenses but the average person that seems obsessed with testing over photographing.
When you hear a lens is soft wide open ask yourself. How often are you going to use the lens wide open?
Then understand softness isn't a fault. Some people pay big bucks for soft lenses. So what are you going to use the lens for? Will you need super sharpness or will you be better off with softness?
All I'm trying to say do what makes you happy and what you can. The lens you can afford is 100x better then the lens you're lusting after but can't afford. The pictures you take with a bad lens will be better then the photos you don't take while dreaming about a great lens.
My lens tests are pretty simple. And I don't test all my lenses. Some of 'em I just evaluate based on how the routine photos look.
Last year I tested all of my manual focus Nikkors (35mm film format). I also evaluated a Vivitar Series 1 70-210/2.8-4 zoom.
I don't think I've ever bothered testing the S-K Xenotar in my Rollei 2.8C. I figured any deficiencies would show up during routine photography. So far, so good - no problems, no apparent need to test.
I do the brick wall test on TMX in bright sunlight and open shade at the closest focus range, some arbitrarily selected middle range and at infinity. I'll usually go downtown for the infinity test since the tall buildings make for better testing conditions.
That's about it. I check the negatives for resolution and distortion. If I see obvious problems such as edge soften, falloff wide open, barrel distortion, etc., I may not bother enlarging that negative. The best frames I'll examine more closely with enlarged test strips.
Most of my lens *types* have been evaluated ad infinitum by other sources. All I want to know is whether mine deviates significantly from the expected performance. I've seldom been disappointed by a lens that other reviews had praised. I have been surprised by the performance of lenses that I hadn't expected to perform so well, such as my 50/2 Nikkor mounted on an M2 extension tube. Can't tell the difference in b&w photos between it and my 55/3.5 Micro-Nikkor on the M2.
The Vivitar Series 1 performed about as expected: very good at the short end, even wide open; soft at the long end until stopped down; very good at moderate focusing distances, not so hot at infinity at the 210mm focal length.
Three degrees of separation from Kevin Bacon.
"The pictures you take with a bad lens will be better then the photos you don't take while dreaming about a great lens"
Terrific idea. Is this your own thought? May I use it in my classes? So often students will ask for advice about "good" lenses.
Of course some lenses are far superior to others, and one pays for what they get, not necessarily get what they pay for. Optics seems to be one field where money can buy quality.
But is the super high cost/quality equipment really necessary? For the better-than-average photographer? I think not. I think one should obtain whatever equipment does the job one needs, whether that need be for finished photographic quality or for personal satisfaction.
R. Eugene Smith
One of the photos I sent out on the Postcard Exchange was shot on an old Perkeo with a wide open Vaskar. It was visibly soft in the corners, with clearly visible aberrations - even on a 10x10cm print.
So what? I got the picture!
But next time (end of October) I'll use a different camera...
-- Ole Tjugen, Luddite Elitist
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Well the words are mine but no way I can claim ownership of the idea. Remember the old song "Love the one you're with"? Really no different.
Personally I think with many lenses you're paying for that small extra. The ability to use it wide open and have it very sharp. Things like that. Usually these are all things you can work around.