I just bought a couple new Tokina lenses (11-16 2.8 and 50-135 2.8) and wondered if you guys have any advice for testing them out. ; They are my first third party lenses and I am worried about getting a bad copy even though the reviews for both have been great. ; When my bank account recovers I plan on adding a Canon 17-55 to give me 11-150 at 2.8. ;
Well at least for focus, I always use the battery test...it's simple and cheap. ; Just line up 5 batteries (AA's work great), spaced close together in a line, then at about a 45 degree angle to that line of batteries, use center or spot focus and put the focus square on the center battery. ; Use a very large aperture for best effect. ; That'll help you determine if you have any back or front focus issues. ; I'd also pull a small aperture blank white shot, to check for anything on the lenses (don't forget to clean your sensor real well before doing this...or at least take a test shot with another camera so you can mark where your dust spots are on the sensor). ; Some standard daylight tests can help determine if the lens is sharp, lenses are aligned properly (be sure to test it at all focal ranges). That's the basic stuff I run through when I get a new lens.
Thanks Justin...front and back focusing was one of my concerns! ; I am also going to take a few shots of a news paper to see how corner sharpness holds up. ; Would you mind posting your method Roger? ;
I taped a magazine page/newspaper page on a wall, set the camera on a tripod at the mininum focusing distance, maximum aperture, manual mode, used a remote release with mirror lockup. I would then look at the results on the LCD screen, and perhaps mess with the focus fine tuning (the more recent prosumer and up cameras have this), and take a few more shots and determine if I need adjustment. The ruler is better because you can see which way your lens is focusing. ; There is a device you can buy/rent to do this now. ; Lens Align.
Has anyone heard of or used the lens alignment test I've seen on the web which uses a test sheet similar to the Lens Align tool. It is pretty similar to just using a ruler, but has a detailed explanation of setup & testing. Actually, I just remembered that I think I heard about it here. ; :-[
Thanks guys! ; I have a Canon 40D so sadly no focus adjustment. ; I will post some test shots tonight!
Cooleo, I think I posted a link to the D70 focus test chart. ; You can print out what is basically a ruler on a sheet of paper. http://focustestchart.com/chart.html
Thanks for the suggestions, Justin and Roger. ; I have always done some rudimentary tests whenever I get a lens, but nothing as thorough as what either of you suggested. ...Now I have an excuse to get a new lens. ; I need to test these methods!
Thanks again for the tips guys! ; I didn't get a chance to test them tonight, but we did head out to a local fair and take a ton of shots. ; I posted the best on flickr in case anyone wants to check out the results. ; I am really happy with them both so far! http://www.flickr.com/photos/trankina/s ... 834664963/
That's the best test of them all - are you happy with them. ; They're passing with flying colors so far!
