Sigma 17-35 exposure problems

[davealan]

Help!

I have a new Sigma 17-35. I am having exposure peculiarities.

First, let me say that my S2 with a Tamron 24-135 has performed flawlessly. Exposures are accurate and consentient, over 1800 frames shot.

Taking a few test shots with the new Sigma, I find overexposure and exposure inconsistency (some over exposed, some properly exposed, same basic scenes). Also exposure inconsistency between same exposure, but different f-stop/speed combinations.

Questions: Is the exposure metering based on the full 35mm frame as the N80 body “sees” it, and the sensor only records the “cropped” image? Could that explain the overexposure? How can a given lens fool a TTL metering system?????

I looked at a Sigma 15-30 and Sigma 17-35 in a store and took some test shots. The 17-35 shots looked brighter - that’s one reason I chose it. Now my outdoor shots (different lens, same model) look overexposed. Hmmmm …

I am quite disappointed in this wide angle as compared to the results from my Tamron 24-135. I need ideas as to possible reasons, or is this common with an ultra-wide on a dSLR.

Yes, I checked for all exposure compensation turned off and all other camera settings are as I usually set them. S2 histograms and PS7 histograms also agree.

Dave

[lightwrangler]

I own this lens too. I found the same results when I used matrix metering. Now I use center weighted metering and find the lens to be more accurate. I know that the lens isn't out because I used a handheld meter and found that it was the camera that was giving me the different exposures.

That being said, I feel that Sigma may not have the same quality control as Nikon or Tamron. (leaving me to wonder about their SD9 camera) While it's true that you pay considerably less for this lens than the Nikon model, it also seems not as well made. I tried 3 Sigma 17-35 lenses in the store before taking mine home. There was a noticable difference in sharpness between them. One of the lenses I tried got an "ERR" message every so often when I zoomed. I guess you get what you pay for.

[Tom Nolle]

I have the 24-70EX and the 70-200 EX, and the only thing I've noticed with the wider angle is that the inclusion of a lot more surroundings can trick the matrix metering. Wide-angle shots often have more dynamic range because they include a lot more subjects in the picture, and it might be that this is fooling the matrix metering. Do a test; set the camera up on a tripod and shoot a neutral subject with spot metering and both your lenses to see if the exposures match. First, check to see if both lenses meter the scene the same, then see if they look the same.

Some lenses can have a defect that changes how f-stop is set or reported to the camera; it may be the lens as well. As far as I know, the S2 only meters on what you see.

Tom

[jeffinkansas]

I just bought the 14mm sigma. I love it!!! It was much cheaper than the nikon equivilent. I have heard the edges are bad, but as this is not a FF camera so what! If anyone would like to have their wide angle back, this is not a bad option.

[Tom V]

Last August, when shopping for a wide angle, I tried a Sigma 15-30 on my S2 and my Nikon F100 cameras. The lens worked fine on the F-100, but gave an error message when mounted on the S2. I could get it to work when I gave the lens a little extra twist in the mount, but it soon would revert to non-functioning. Somewhere in the mix, a specification was not adhered to exactly, and it caused problems on my particular camera/lens combination.

Perhaps Dave's wild exposures are caused by an barely-functioning lens-to-camera interface? It might be the particular individual lens (or camera) that is making a 99% contact and getting the exposure computation wrong.

Other S2 users own the model lens and report no problems at all. I have a new Sigma 14mm and a 10+ year old Sigma 70-210 ƒ2.8 Apo zoom, that work very well. The only lens I ever had to repair was a Nikkon 20mm, so I can't say that buying only Nikkor lenses will guarantee perfect function.

An advantage of going to a camera store and buying a lens from a person face to face is that you can test a lens - and with a digital camera - see the results right away.