# Question on new 16-35



## Tec972 (Jul 10, 2013)

Hey Gents,

I will open my first post on this great forum with a question.

I just received a brand new 16-35L II today. I tested the 16-35 on my old 20D body (I will not be using it on that body, don't worry!!) and when I compared the lens to the 10-22 the DOF on the 10-22 was SO much greater at same aperture. I don't understand why DOF on the 16-35 is not the same when used on same body. I understand the DOF being much different on my full frame vs. cropped, but its exactly why I used my old camera do a lens comparison. Wanted to see how the new L held up against the old 10-22. I can post the comparison pics if anyone needs to see.

Thanks,

Mike


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## Vossie (Jul 10, 2013)

Some pics would help indeed. I still have my old 30D and 10-22 around so should be able to replicate your phenomenon.


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## Tec972 (Jul 10, 2013)

Ok here are some shots. I shot both at 16mm. I know during normal shooting the focus distance which was about 3ft. would give me what I got but i just couldn't believe how much more was in focus on the 10-22. Please excuse the clutter, (I shot that on purpose)


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## Tec972 (Jul 10, 2013)

this is the 16-35


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## Mt Spokane Photography (Jul 12, 2013)

In order to compare, you need a controlled shot. The exposure is obviously a lot different, and a camera does not always focus where you think its focusing.

With both lenses at the same distance from the subject and same aperture on the same camera, the FOV will be identical.

So, either you have a lens problem, or the lenses are not focused on the same point.

If you set the lens to 3 ft by looking at the numbers in the focus window, they are only approximate, and that would cause a difference. Autofocus will also vary and may lock onto different items where there are many to pick from. You won't see this in the viewfinder as long as they are somewhere near the focus point used.

If you have manually set ISO, aperture, and shutter to be the same, one of the lenses likely has a aperture problem. If not, set them to be the same so you have comparable images, and arrange it so that there is only one item in the foreground for the camera to focus on, there are just too many possibilities in your photos..


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## Tec972 (Jul 12, 2013)

Thank you so much for the reply Mt Spokane,

I have found comparing these two lenses that the 16-35 overexposes by approx. 1/3-1/2 stop compared to the 10-22 which I don't mind. I knew going into my purchase of the 16-35 that I wasn't going to expect tack sharp photos. (They are in the center) however but getting toward the edges of the frame on the left and right, it starts to deteriorate rather badly, even on the cropped sensor which I did not expect. I also did not expect my 10-22 to just smoke the 16-35.

I do not think there is a focus problem with the 16-35. It doesn't seem to ever miss. Everything you said about the DOF I realize and have thought about that, which leads me to believe that distance from sensor to lens rear element may be the issue?? At 16mm there is a difference between them. I know it's not technically an apples to apple comparison because I'm comparing an EF / EF-S lens. I don't know. But I was thinking DOF should be identical also, thats why I have posted here.

On the test shots I have manually set ISO, aperture and shutter. Both shots were taken on the tripod and lenses were carefully changed and they did focus on the same object which was the red bottle


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## jcns (Jul 12, 2013)

2.8 vs 3.5-4.5.
You will not get the same DOF on both lenses because of aperture values are not the same.


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## Vossie (Jul 12, 2013)

What aperture did you use on both shots? I agree the DoF looks shallower on the 16-35 shot, but it also looks a bit narrower (you could check that you have the same angle of view in live view as 16mm one lens is not per se the same as 16mm on anorher lens). Indeed the shot have a different brightness, but -as long as you have the same aperture and focus point- not impact the DoF.


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## Tec972 (Jul 12, 2013)

Jcns,

I shot same exact settings on both lenses aperture included. I knew the 10-22 can't get to 2.8. After taking other shots I'm starting to think it has to do with distance of rear element to camera sensor. Realize that the 16-35 is just not very good on a cropped body. Not seeing any real difference in detail with the 16-35 over the 10-22. Pretty disappointed. Maybe my copy just isn't too hot.


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## Tec972 (Jul 12, 2013)

Vossie said:


> What aperture did you use on both shots? I agree the DoF looks shallower on the 16-35 shot, but it also looks a bit narrower (you could check that you have the same angle of view in live view as 16mm one lens is not per se the same as 16mm on anorher lens). Indeed the shot have a different brightness, but -as long as you have the same aperture and focus point- not impact the DoF.



Hey Vossie, I shot both at f/4. The reason that the focal length isn't balls on is because there is no 16mm mark on the 10-22. As I have continued shooting it's the same result at different focusing distances. This particular shot just happened to have a focus distance of about 3 feet. However after putting the 16-35 on the FF body I am not having the DOF issue like in this picture. On the FF the DOF is much deeper than on the cropped body.

I never would have guessed had I not tried this. Learn something new everyday!!

Although I am still not that enthralled with the copy of the 16-35 I have.


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## dgatwood (Jul 12, 2013)

Tec972 said:


> I have found comparing these two lenses that the 16-35 overexposes by approx. 1/3-1/2 stop compared to the 10-22 which I don't mind.



That difference in brightness is significant, IMO. I suspect one of the lenses is outright lying about the aperture that it is giving you, which means your DOF is different because the aperture isn't really the same. The 10-22 is much darker, which, assuming approximately the same field of view (there's a small difference, but not enough to make that much difference in brightness, I don't think) means that the 10-22 is using a smaller aperture, which would result in a sharper picture.

Try taking photos in the same location with approximately the same field of view, but adjusting the 16-35's F-stop number higher until you get the same brightness. I suspect you'll find the DOF to be similar in both lenses. Only then can you fairly compare the two lenses.

Incidentally, this test is high on my to-do list when I get home, as I just bought a 6D and a 16-35 to match the shot angle that I used my 10-22 to achieve on my XTi. I'll see if I can put together some good test shots on the XTi for comparison purposes.

The fact that you're not seeing the DOF problems on a different body further supports that theory; there's probably a camera-specific firmware bug involved in aperture reporting.


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## Jeremy (Jul 12, 2013)

I shot events with a 16-35II on a crop body for a few years (before moving up to a full frame and a 24-70). I LOVED the combo and found the images incredibly sharp. 

As for the DOF difference, I'd guess the reason is EF vs EFS. On a crop body, you only see the center of the 16-35II EF, but you see almost all of the EFS lens. Lenses get funny as you get to their outer edge.


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## Tec972 (Jul 12, 2013)

dgatwood said:


> Tec972 said:
> 
> 
> > I have found comparing these two lenses that the 16-35 overexposes by approx. 1/3-1/2 stop compared to the 10-22 which I don't mind.
> ...



My bad, this was first comparison shot I took and I am mistaken after looking at the exif, the camera metered the shot different with respect to shutter speed. The camera chose 1/40 shutter and 1/25 between the two shots. I made sure other shots were the same settings. The 10-22 vignettes quite a bit vs. hardly any vignetting on the 16-35.

If some of you guys have the same combo I do I would be very interested to see how your 16-35's are holding up against the 10-22 on a cropped body. It seems the right side of my 16-35 is much worse than the 10-22 with the 16-35 looking a tad better in resolving detail in center


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## AudioGlenn (Jul 12, 2013)

Tec972 said:


> dgatwood said:
> 
> 
> > Tec972 said:
> ...



1st off, you need to redo your test in MANUAL mode. Then you can start comparing apples to apples. The camera shouldn't be choosing your shutter speed. Set the same exposure with ALL the same setting in M.


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## Tec972 (Jul 12, 2013)

The more I'm shooting between the two, the more I think the DOF issue I originally posted about is due to EF vs. EFS. The problem gets better as focus distance increases and I will chalk that up to rear element to sensor distance difference between the lenses with the DOF phenomena exaggerated at closer focus distance to subject. My old kit 18-55 EF-S lens was exhibiting the same behavior vs. my 24-105L. (sadly the 24-105L didn't look any better than the kit lens on that old 20D body. UGH!!) 

I'm thinking poor right side frame performance on the 16-35 is due to it being at it's widest vs. the 10-22 @16mm getting some breathing room along with lens copy variation. (Mine not being that hot). I tested it against another 16-35 at a camera store yesterday which only had one copy and theirs was better on the right side of the frame.

I'm not usually a huge pixel peeper except when I get a new lens. I don't seem to ever get a good copy off the bat with more expensive canon lenses. The 24-105L I initially got with my 6D kit about made me sick to my stomach it was so bad. I like to find out about any possible issues once, then never worry about it again so I can get to more productive things and enjoy taking pictures, but I also like to know where equipment limitations lie.


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