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JDoran Apr 27, 2006 11:36 AM

Hi everyone, I just purchased the canon 10-22mm lens and the 85mm f1.8 lens and I want to run some tests on them to find any defects and to measure the quality. I was just curious what tests you guys typically run on your new lenses. I am looking for a thourough, controled test. Thanks for any tips. -Justin

Meryl Arbing Apr 28, 2006 3:53 PM

I woyuldn't worry about a new Canon lens. There should be no sample variation at all. Now, if you were talking about 3rd party lenses...then...they cut corners and I don't even bother considering them.

rey Apr 28, 2006 5:12 PM

It's a good idea to test your lens, not really to see if it's broken, but more to understand it's capabilities. ie what f-stop is acceptable, best, etc.

Normal "lab" tests include the newspaper test, and brickwall test.

Newspaper test is where you mount the camera on a tripod and tape a newspaper (with lots of text, not pics) to a wall and take pictures on different f-stops and different focal points. Make sure the area is well lit. This would reveal the len's sharpness and softness. Be sure the check the edges. Don't go crazy with it though. I would just test on three or four focal lengths for the zoom. And use full f-stops, and not thirds or halves.

Honestly, the lens you got are pretty good. They are not the cheap Canon stuff, so you shouldn't see any problems. I have the cheapo kit lens and a cheap 70-300 and I needed to test it.

The brickwall test is just that, you take a picture of a brickwall and see if how bad the edges curves.


eric s Apr 28, 2006 7:00 PM

Unfortunately, Canon does have quality control issues with some lenses. The 100-400 is a classic example with a wide variance in sharpness between individual lenses.

Testing any camera equipment is best done in very controlled conditions. Lots of light, on a tripod, no vibrations. This means don't do the test near the fridge (or anything else with a compressor) because it will shake the floor when it turns on. My suggestion is, if you have enough light, test it in the basement.

Pick a nice target with good detail and take several pictures of it. Manually focus, to remove the possability of the camera causing trouble (instead of the lens causing trouble.) This assumes, of course, that you are good at focusing manually.


geriatric Apr 29, 2006 1:16 AM

Remember if you are thinking in terms of resolutionyour monitor is not much good

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