How to test the quality of 3 lenses?

[tsmakrakis]

Hi there, I want to test the quality of 3 of my lenses.

Canon 50mm 1.8
Canon 70-200 4L
Tamron 28-75 2.8

Is there any chart that I can print and take a picture of to compair the results or how do I test the lenses?

Thanks!

[chtgrubbs]

There are charts and techniques available here:http://www.normankoren.com/Tutorials/MTF5.html and here:http://www.bealecorner.com/trv900/respat/#EIA1956 and here:
http://www.graphics.cornell.edu/~westin/misc/res-chart.html

[xmetal2001]

Seeing as those are the three lenses i eventually wish to acquire, i would love to see the results.

[tsmakrakis]

I will try post them when I am done :)

[tsmakrakis]

Here you go guys... a simple test.
1/30th, F8 for all the shots.

http://www.themomento.com/forumpics/Tamron28-75.jpg
..
http://www.themomento.com/forumpics/Canon50mm.jpg
..
http://www.themomento.com/forumpics/Canon-70-200.jpg
..
http://www.themomento.com/forumpics/Image2.jpg
..
http://www.themomento.com/forumpics/Image3.jpg
..
http://www.themomento.com/forumpics/Image4.jpg
..
http://www.themomento.com/forumpics/Image5.jpg
..
http://www.themomento.com/forumpics/Image6.jpg
..
What do you think?

[tsmakrakis]

I encourage you to print the target
http://www.graphics.cornell.edu/~wes...res-chart.html
and take a picture with your "BEST" lens :)
Post it here - Thanks - I think that will help a lot of us to decide which lens to buy.

[tsmakrakis]

What do you guys think? Say something :)

[Citizensmith]

Thanks for your time on the charts.

However, personally I don't put too much stock in lens charts as I much prefer real world tests. Basically, although these can show the resolving power of a lens they do nothing for things like bokeh, ghosting, flare, chromatic aberation, and vignetting. They are also very dependant on accurate focusing which is hard to reliably achieve under test conditions.

I don't mean to malign your efforts, just to point out that a photo of a lens chart really shows only a small amount of a lenses abilities and flaws.

[ed2day]

I don't see a big difference, which is pretty typical at f/8. You'll see bigger differences at wider apertures. But testing is a lot tougher too. What printer did you use--your test sheets came out a lot better than mine. Having a 20D helps too. I ran into a problem where the resolving power of the lens (at wider fstops) and the pixel resolution of the camera and printer all kind of come together to cause some wild moire patterns. I like doing this kind of thing and I think there's value in it if you do it right, but I certainly agree with CitSmith--resolution is just one facet of lens performance and doesn't even totally determine perceived sharpness of the lens.

[tsmakrakis]

I agree that this is not the most accurate way to tell which lens is the best but regarding resolution are these tests lying if focus was accurate?
If instead of the target I was taking a closup portait of a model - wouldn't the results would be the same resolution wise?

> ed2day: I used a simple laser printer to print the target.

[ron chappel]

Charts aren't needed for lens tests,real world scenes are just as good and sometimes better.

Here are some tips to get ACCURATE, CONSISTANT results:) :

Use a tripod for all shots

The normal small variations in autofocus performance can completely invalidate a test so use manual focus.Take several shots at each setting,refocussing each time,then keep the best image .

Never resize (up OR down) in photoshop to compare different focal lengths.Even the slightest resizing ruins ultimate sharpness.
Move the camera closer or further away from the subject to compare different focal lengths on equal terms :)

Test at different apertures by all means but be aware that stopped down lenses tend to be very close in performance.You'll see most differences near wide open

Beware of changing lighting (occasional cloud,etc) because this will change the contrast of the scene which has a big effect on apparent sharpness

All the best with it!

[Andy_T]

Tassos,

at f/8, you might get similar results with the EF-S 18-55 kit lens.

Taking shots wide open and slightly stopped down (e.g. f/1.8, f/2.0, f/2.8, f/3.5, f/4.0, f/5.0, f/5.6) will allow you to judge which lens you want to use for which occasions.

I normally use my 50/1.4 and 28/1.8 at something like f/2.5, and my Tamron 28-75/2.8 at f/4.0 because these are the apertures where they really shine.

Best regards,
Andy

[tsmakrakis]

For studio work I use F11 so that is why I did the test at F8.
Thanks guys for posting - it really helps me understand how things work.

[Andy_T]

Tassos,

you have some beautiful pictures at your website :D

Hope you share some of your pictures now and then.

Best regards,
Andy

[tsmakrakis]

Haha - I have been so busy but I will try to post some - I am new to the forums world :)
Thanks, I am glad you like them.

[LeeDye]

Hmmm, I would think that the resolving power of an lens would demonstrate how effective the lens would be in ,"REAL WORLD" scenarios. Thank you for posting. Your lens test is very similar to what I have discovered as well with my lens in ,"REAL WORLD" pictures. The Tamron is very sharp and in fact is sharper than my Canon 50mm f/1.8 in many situations which is why I ordered up a Canon f/1.4.
Lee

[tsmakrakis]

Is the 50mm 1.4 sharper than the 1.8?

[LeeDye]

Is the 50mm 1.4 sharper than the 1.8?

Most say it is, some say it is not worth the extra cash.

http://www.fredmiranda.com/reviews/showproduct.php?product=29&sort=7&cat=2&page=1