How much should I worry about Sigma quality control?

[acrummey]

I use a Sigma 24-135mm f2.8-4.5 lens regularly on my Pentax DSLR, but only because I was lucky. Over half of the members of another forum who purchased this lens (for Pentax) found that it caused electronic issues which included no menu display on the camera (I saw this happen once on my DS). The optical performance of this lens is quite good, but as I said, I got lucky. I have switched back to the Tamron sourced FA 28-80mm lens as my walk about lens since the Sigma is also very large and heavy.

 

A great lens for covering events like weddings however (the PJ style, not the posed stuff where primes are so much nicer). But I will not be rushing out to buy Sigma lenses. BTW I got this lens for $75 brand new with warranty from a Sigma dealer (shows that there may have been some issues here with that pricing).

[michael_kuhne]

It was for me reassuring to read Godfrey's experience with the Pentax 12-24mm, which I also own, as not having a significant CA problem in actual use. I have not used mine enough to see how often I might encounter any. I bought this lens because of the rebate savings and its otherwise superb rated performance in a wide zoom. If it does average in the neighborhood of a dozen or more out of 100 shots, that might sometimes be bothersome to me. We shall see. My use also usually includes a film camera, so I often have the option of switching to that for wide angle use with my inexpensive but fine Tokina 19-35mm.

 

I have frequently read of CA's being "easy" to correct. Certainly, light falloff issues are harder to deal with when that is visible. But this "easy" procedure does not appear "easy" to someone like me. Most of the programs I do have, pro Adobe PS, etc, etc sit in disuse because I find them far to troublesome and time-consuming to bother with. "Easy" to me in effecting CA correction would be clicking a "CA ERASE" button, and done.

[michael_kuhne]

Say Ira, I have the Sigma 24-135 as well and so far, no problems. If that "no menu" does arise, however, it sounds like a lens contact problem to me. Perhaps a simple cleaning of the contacts may be the answer.

[godfrey]

Michael,

 

If you have been using the DA12-24 and you haven't seen much of a CA problem, then

you don't have one. ;-)

 

"Easy to correct CA" works like this:

 

- Capture in RAW format.

 

- Open file in Photoshop CSx + Camera Raw or Lightroom.

 

- In Camera Raw, click on the Lens tab. Set the view to 100% and scroll to an edge where

you can see the CA. Hold the Option or Alt key down when you click on the Red/Green

adjustment slider. The view will change to show you JUST the Red and Green channels.

Slide slider back and forth until the colored fringe disappears. Do the same for the

Blue/Yellow slider.

 

- In Lightroom, go to the Develop module and open the Lens Correction panel. Do the

same as above.

 

That's it.

 

CA varies by lens, aperture and focal length setting if it's a zoom. The corrections don't

change once you've found the right settings for a given lens. Soon as you find the

combinations that you use a lot and the situations that you need to correct for CA a lot,

you set up a correction preset and just apply it. I have presets like that for just one lens, a

lens which I've since sold, but any time I open files up that were made with that lens I just

apply the preset and continue with the rest of the image adjustment processing. ;-)

 

Godfrey

[acrummey]

Michael, I use the Sigma 24-135mm for much of my "commercial" photography (the one or two weddings per year that I do for friends). I have found the lens to be very good except for lens flare which is not as well controlled as in the SMC lenses.

 

Ira