Testing 2 Lenses side by side - Ideas?

[PhotoJourno]

Hi everyone-

I started a thread (http://photography-on-the.net/forum/showthread.php?t=204838) about two lenses I am trying to choose in between.

Canon 70-200mm f/4 L (Pros: My first L lens, sharpness, IQ)
Sigma 70-200mm f/2.8 (Pros: Aperture, HSM, DG DX and etc)

I got the Canon, and chose to send it back, as my comparison to the Canon III 75-300 should have been so abyssmal, and yet though better, it was not enough to call the L an absolute keeper (yes over the III, but not as a great piece of glass).

So tomorrow I will have a 12 Hr with both lenses. If you were in my position, what kind of test would you run to see which lens to keep?

(Background info, I am looking for a low light lens to replace my Canon 75-300 III, and the two affordable options were the Canon L lens -pros is L, cons is f stop is 4 at best- or the Sigma -pros is f/2.8 HSM, con it is not an L quality lens-. I do press photo indoors, conference rooms, City Halls, etc. So I do want the edge in aperture, but I thought maybe the L would make up in IQ the missing f stop to the sigma).

So far, the tests I ran were:

- 100mm at f/4 and f/8 for both lenses
- 200mm at f/4 and f/8 for both lenses

Of course in as similar conditions as possible, with tripod, same camera, and same point of focus (so as to compare IQ side by side).

How would you test these two lenses if you were in my shoes ?....

[gasrocks]

If you are a pixel peeper/peeker - tripod, MLU, remote switch,etc. However I'll vote for real life pix like what you boght it for (people, sports, whatever.)

[CorruptedPhotographer]

I'll vote for real life pix like what you boght it for (people, sports, whatever.)

Ditto. Arent you taking this to a level thats not really neccessary?

[FlashZebra]

As above with some additions:

Heavy duty tripod
Camera in mirror lock up mode
Very careful manual focus (you might want to also check the autofocus performance)
Remote shutter cord
Black card to blind eyepiece during exposure (so you can remove your eye from the eyepiece but still not allow light to enter and change the exposure - just hold in in place near the eyepiece without actually touching the camera)
A subject with a lot of detail over the entire frame (for both center and edge sharpness)
A subject that is relatively flat (a brick wall works nicely)
Get at image at every F# up from the largest to F/16.
Test at several focal lengths.
Keep good records.

You might also want to check out these nice reviews.

http://www.photozone.de/8Reviews/lenses/canon_70200_4/index.htm

http://www.photozone.de/8Reviews/lenses/sigma_70200_28/index.htm

Enjoy! Lon

[davidfig]

What are your top three uses. Go out and find those environments.

For me outdoor portrait, indoor portrait, indoor wedding (for this range). I would look to test it in those environments.

Since you want to do indoors the 2.8 is a must, but the contrast, color of a L is sure hard to beat.

[rklepper]

First thing is you have to decide how much low light shooting you will do. That will narrow it down immediately.

[TeeTee]

Thanks for the test, eagerly await the results.

[garyjlambert@comcast.net]

buy the 70-200 f2.8 L IS usm. done

[Lightstream]

Not much more to say. Agreed that you should shoot it in its desired environment. Handhold both indoors, since you are going to do that in the field.

For sharpness tests, do the tripod thing. For me, I forego MLU since I seldom use MLU in the field except for long exposures, it's personal and depends on your needs.

Shoot the Sigma wide open in both situations, and analyze the IQ. This will give you an idea of whether the Sigma is adequate at f/2.8. At 200mm wide open it can be a little soft. Stop the Sigma down to f/4 to see whether it does what you need it to do. If it is close enough to the L, keep the Sigma, but be aware of the f/2.8 tradeoff in terms of absolute sharpness.

Colors and contrast on the Sigma are excellent though. Compared to my Ls, I'd say the L's have a tiny edge but I cannot always identify which is which.

Forget the f/8 tests IMHO.. most lenses look good at f/8 and the differences are very narrow. Your 75-300 looked decent at f/8, though the L was sharper. I seldom if ever shoot a telephoto at f/8, so I'd pass on it. f/8 would be very relevant for my landscape lenses though.

Either way, go with your gut feeling and the lens you like more even if it doesn't fit nicely into these criteria. And if all fails, 70-200 f/2.8 IS USM L as has been said :D

[Tee Why]

send it to fstopjojo

[Lord_Malone]

How would you test these two lenses if you were in my shoes ?

If I were in your shoes, I wouldn't be wasting my time with lens tests. Especially in the line of work you're into. If you do a lot of indoor press shoots, the 70-200L IS is a no brainer. And if the publication you're shooting for is funding the purchase, why not get the best? If you're freelance or a hobbyist, get what you're pocketbook can afford to achieve the desired result. In your case I'd go with the faster Sigma.

[PhotoJourno]

Just got the Sigma, and it took me about 20 minutes to officially make up my mind. It truly was a no brainer once I had both lenses in hand. Did some crude testing, photos coming up. But the L does not hold much of an edge over Sigma (only in a couple of areas, i.e. its a white lens, its smaller and lighter). But Sigma operates incredibly well, has the extra f stops, and now my Bigma has a little brother. I shall call it, Mini-Bigma.
I wish I could jump into the pool with the 70-200 IS L, but that is a lot of money for my first L lens, and no I do pay myself for the equipment 90% of the times.
So as most said, given the circumstances, the Sigma is the chosen one. BRB with the pics,

[stupot]

I wish I could jump into the pool with the 70-200 IS L

I wouldn't recommend that.

[lmelendez]

I do press photo indoors, conference rooms, City Halls, etc.

Go to a room with similar conditions and take pictures with both lenses the same way you do it when you are doing your job. Take them to the computer and check the results. Get the lense that give you the best pictures.

I really don't see the value of doing 'controlled tests' if you are not gonna shot in 'controlled' conditions.

Leo.

[Lightstream]

Just got the Sigma, and it took me about 20 minutes to officially make up my mind. It truly was a no brainer once I had both lenses in hand. Did some crude testing, photos coming up. But the L does not hold much of an edge over Sigma (only in a couple of areas, i.e. its a white lens, its smaller and lighter). But Sigma operates incredibly well, has the extra f stops, and now my Bigma has a little brother. I shall call it, Mini-Bigma.
I wish I could jump into the pool with the 70-200 IS L, but that is a lot of money for my first L lens, and no I do pay myself for the equipment 90% of the times.
So as most said, given the circumstances, the Sigma is the chosen one. BRB with the pics,

Congratulations. Enjoy the power of f/2.8.. :)

The Sigma is my stopgap too, until the IS L shows up.

[PhotoJourno]

I hear all of you, and share your comments. 70-200 L IS seems to be the best of the best. However I cannot afford that lens, and I need something I can use on the meantime. End of the story and two lengthy threads, the Sigma EX series with 70-200 f/2.8 stole my heart and took a macro of it. ( ??? )
It took me less than 10 frames to make up my mind:

- Quality of the lens build was similar, and I do love black crinkle finish.
- Length and With was not consequential at least for me. I usually end up carrying my bigma everywhere I go, just in case.
- IQ: First, I took the L f/4. Nice lens. Then I grabbed the Sigma, and took some photos at f/2.8, and the performance was great. I stepped it up to f/4, and I could barely tell which was which. then I stepped it up to 8, and the sharpness was even greater.

Ol' Canon L was on its way out before I even finished looking at the Sigma's manuals.
Here are some pics of the Sigma rig, and also of the Lens by Lens comparison. Not that much difference, although price-wise was almost $300. Canon L is $584, Sigma was $899, and Canon L IS 2.8 is $1600. So I still managed to get second best for half the price.

Now I stop with the technical crap, and get some sleep, so I can go out and take photos. After all, the tools of a craftsman are only as good as the skill of the hand holding them.

[Lord_Malone]

Now I stop with the technical crap, and get some sleep, so I can go out and take photos. After all, the tools of a craftsman are only as good as the skill of the hand holding them.

I hear you, Mario. Can't wait to see some of your work. Now go out and have fun with that fast Sigma! ;)