Do I have a duff lens??

Hi all,

I have just switched from Canon to Nikon and I am worried about my shiny new 24-70 f2.8... At f 2.8 it doesn't seem to be any sharper than my old Sigma 24-70 f2.8 on my Canon 7D. At f8 it looks pretty good...

Could anyone let me know if the attached test shot is particularly bad...

(70mm - f2.8 - ISO 100 - 1/5 sec - on tripod with remote control mirror lock up)

Any comments or thoughts greatly appreciated!!

Thanks!

Welcome to the forum! There is no way of judging a lens's sharpness from the scaled-down photo you attached. This forum will not let you upload a full-size photo. You need to either put it somewhere else (e.g. dropbox) and provide us with a link, or upload a few 100% cut-outs here.

HI Marek,

Thanks - here you go:

https://www.dropbox.com/s/ow9iixyn1c8vjn0/_DSC0837.JPG?dl=0

I was slightly surprised that it seemed that I could attached the full size one - now I know I didn't!!

Cheers

GRT said:

HI Marek,

Thanks - here you go:

https://www.dropbox.com/s/ow9iixyn1c8vjn0/_DSC0837.JPG?dl=0

I was slightly surprised that it seemed that I could attached the full size one - now I know I didn't!!

Cheers

Click to expand...

I'm looking at what you've uploaded but I'm not sure what I"m seeing. Is that the actual image file out of the camera? What camera are you shooting with and what settings are you using? Are you shooting RAW or JPG and are you doing any post processing?

EXIF data says it is a D610 with 24-70 @f/2.8. There is some softness in the left part of the image. I'm not sure if this is the lens, or perhaps the chart was not all in focus. It might be that it wasn't perpendicular to the camera. I'd suggest shooting a few more pictures to be sure. Also, go outside and take a landscape photo, see if everything is sharp.

I have downloaded it

100%

Horoscope Fish said:

I'm looking at what you've uploaded but I'm not sure what I"m seeing. Is that the actual image file out of the camera? What camera are you shooting with and what settings are you using? Are you shooting RAW or JPG and are you doing any post processing?

Click to expand...

Setting are: 70mm - f2.8 - ISO 100 - 1/5 sec - on tripod with remote control mirror lock up. It is the images out of the camera with no processing, only converted from RAW to JPEG from LR....

Thanks!

Gah... Now that I've *downloaded* the file (durrr) I can see what's going on. That's what I get for posting at this hour before my first cup of coffee...

In looking at the photo at 100% it *definitely* looks soft to me. Could be the lens is just soft wide open; try stopping it down two stops and repeat the test. It could also be the lens is front/back focusing and that can be adjusted for in the menus. It's an unsharpened RAW so maybe that has something to do with it, but it does look soft to me at 100%

....

I just checked DxO marks and the Sigma on the D7 scores 8 at optical sharpness while the Nikon scores 15 on the D610. The Sigma scores 16 there. On the D610 both lenses should be fairly similar but that it is identical or worse than the Sigma on the Canon would be strange.

The softness disappears when sharpening some in LR.

Thanks, you should never attempt anything before coffee!!

It's pretty good above f4 and really sharp at f8 and f11. I'd read reviews of the lens before buying and it was suggested that it was just as sharp at f2.8... not sure about it's a focussing issue because I've tried manually focussing with live view and can't get it any sharper....

Hi J-see,

Yeah, I checked out the DxO scores before buying and expected the lens to be much better...

GRT said:

Thanks, you should never attempt anything before coffee!!

It's pretty good above f4 and really sharp at f8 and f11. I'd read reviews of the lens before buying and it was suggested that it was just as sharp at f2.8... not sure about it's a focussing issue because I've tried manually focussing with live view and can't get it any sharper....

Click to expand...

Considering the scores J-see posted from DXO Mark (which are not all that impressive, really... I mean they're not "bad" but...), and the fact things look so much better at f/4 and above, I think it may simply be the lens does not perform well when shooting it wide open. I would certainly expect to see better sharpness overall from a D610. I too am finding the shot cleans up well in post processing, though, so that may be your saving grace when shooting this lens wider than f/4.

...

Two words - Focus Calibration

You could have a touch of minor front/back focusing going on. Get that locked in first. It doesn't look bad and I suspect that might do you.

BackdoorHippie said:

Two words - Focus Calibration

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My advice as well. I've calibrated every lens to each camera body, and the improvement is substantial. FWIW, I use the FocusTune system from Michael Tapes Design.