[EarlVonTapia]

(This rant is kind of long, but it comes about because I got a new lens that I wanted to use, but ended up not being able to use it because of quality control issues.)

Earlier this month B&H had a sale for the Sigma 30 1.4 - $349 new. I've always wanted a "normal prime", and the Sigma 30 was close enough to what I felt is a good normal focal length for me (24-28 would be ideal, but there are no good cheap AF options in that range). I pulled the trigger as a Christmas gift to myself.

The lens arrived this past Thursday, just in time for a holiday weekend getaway. There wasn't much time to do any real testing of it at home aside from a brief mechanical inspection and a few fun shots, but I figured that a weekend of (careful) regular use would let me know if it was a keeper.

One of the first things I notice about the lens is that one of the aperture blades has a spot on it. At first I thought it was a piece of dust, but upon closer inspection it looks more like it's some sort of permanent "pock mark" or bubble. The blades still open and close smoothly so I don't think it will have any effect on the mechanics or picture quality, but it suggests to me that if the quality control person missed this then there might be other mechanical/optical things they missed. Also, I think the aperture blemish will hurt the resale value of this lens in the future.

On to the testing. I started taking lots of pictures early on of anything and everything. I own a Pentax F 50 1.7, purchased a few weeks ago second hand off of Craigslist, and it's razor sharp wide open and ninja-sword sharp at smaller apertures. Having read reviews of the Sigma 30 1.4 here on the forums and on other sites that use fancy testing machines, and after seeing pictures taken with it, and combined with my experience with the F 50 1.7 (a somewhat similar lens), I felt that I had a reasonable expectation of how sharp the Sigma 30 1.4 should be.

That expectation was not met. The Sigma 30 1.4 did not deliver in the sharpness department. The pictures I took seemed a bit fuzzy when I zoomed into them on my LCD. They certainly did not seem as sharp as pictures I normally see with my other sharp and fast prime. I thought that it might be a focus problem, but I played around a bit with the K30's focus adjustment and could not come up with a fix, and I did not want to be spending chunks of holiday time trying to fix it. It also seemed to have trouble focusing at infinity. The Sigma also performed poorly in low light, as slightly fuzzy pictures combined with increased ISO noise created some barely usable photos. The next morning I just put the Sigma away so it wouldn't get damaged, and so I wouldn't ruin anymore shots from the weekend. Disappointing. I went back to my kit lens and got some decent shots from that.

So the final "test" for the Sigma to save itself was a head to head with my F 50 1.7 when I got back home. This meant taking a variety of pictures with both the 50 and the Sigma 30 and comparing them. Sadly, the Sigma was slaughtered by the F 50. The Sigma went back into its plastic bags, back into its pouch, and back into the Sigma box and then into the box the package was shipped in.

The only time I bought a lens from a store (I usually buy used online), I asked to see two copies, gave each of them some brief camera time, and picked the one that I liked the best. I don't want to be "that guy" who tries out 6 or 7 copies of a lens at a store before picking one, only to return the next day and asking to see even more copies because their test charts at home revealed some flaw in the lens. That being said, even taking into account my limited time in the photography world, I think I know enough to judge when there's something wrong with a lens.

I am aware of Sigma's infamous quality control problems. These forums are littered with posts about bad Sigma lenses with all sorts of issues, and even professional review sites make mention of when they get these bad lenses. Of course, this is not just a Sigma thing, but I perceive it to be more common with Sigma than with other brands. But now, I have a real life experience to back up my perception.

This was my first new Sigma lens purchase, and I think it might be my last, because I don't want to deal with the increased hassle of making sure I get a "good copy" of something I'm spending hundreds of dollars on, whether its by going through multiple copies, or by sending it into some place that will calibrate my camera and lens (keeping me away from my camera for a number of days/weeks). Maybe if there's a lens I really need (like a 70-200 2.8), and I find a good condition used copy that has already been put to use by someone else and therefore any QC issues it had were discovered and fixed, then I'll give Sigma lenses a look. For now, no. Sigma claims to have revamped their QC processes with their new developing "art-contemporary-sports" lens lineups, but I'll wait until the reviews roll in and judge for myself.

So I guess I'll go with my original plan of saving up for the FA 31.

[vrrattko]

Maybe you should give a Sigma some more testing - try focusing via Live View....one of the reasons why Sigma seems to be unsharp may be bad focusing. Also try microadjust AF, try photos with various apertures. This Sigma is supposed to be sharper than FA31 in the image centre. If I were in your shoes I would make photos with various apertures and focused to various distances. For example if you focus precisely with Live view, stop down the lens to lets say 5.6 and the photos are still unsharp, then you really have a bad copy.
But to warn you, I had FA31 and until I microadjusted AF it acted exactly like your Sigma, it just wasnt sharp.....after adjustment whole world of difference ...

[JohnBee]

... So I guess I'll go with my original plan of saving up for the FA 31.

Try getting a focusing chart.
If you can't afford one, download one of those printable/foldable ones and go with that.
The most important thing to do at this point is to identify the problem.

[beachboy2]

I'm impressed with all my Sigma EX lenses, including a 30mm F1.4. First step is to check the focus adjustment as suggested above. You don't even need a focus chart. Just an A4 page of text. Highlight the middle line and then take photos at a 45 degree angle to the page and see if there is FF or BF. Adjust in camera and you will probaly have the problem solved. Good luck and
cheers
bb2

[JinDesu]

Or just liveview it.. if it's not sharp when using liveview, then it's just not sharp.

[EarlVonTapia]

Thanks for the replies. I have a bit of a cooler head now. I will give the Sigma one more try. That page test sounds simple and effective.

I will add that I'm not going to compromise on this. I bought this lens because I wanted something that can go as fast as F1.4, provide serviceable pictures at that speed, have autofucus, and allow me to use my viewfinder. If I have to compromise on one of these things, it goes back, and Sigma QC can suck up the lost sale now and forever. I'm in Vancouver, and sending things back and forth to the East Coast for exchange/repair/calibration is a poor option because of the shipping cost and the time delay (it took weeks for the lens to get here in the first place).

Also, that spot on the aperture blade still really bugs me. Did they just reuse these parts?

[IchabodCrane]

Have you tried shooting at the same aperture setting as the other two primes? If you have a slight FF or BF problem, it's going to be more accentuated by the F/1.4 aperture. As mentioned earlier, the best test to determine whether you have an unsharp lens or a FF/BF problem (whether in the camera or in the lens) is to shoot in Live View to see how sharp the images are.

[EarlVonTapia]

Thanks again for the replies everyone. I have decided to keep the lens.

Sharpness was perhaps the wrong word to use when describing what I thought was wrong with the lens. After doing the "page of text" test (brilliant test btw, I'm going to use it in the future), the Sigma was able to perform as well as my F 50 1.7 in the sharpness department. The problem is that the focusing is a little more weird on this lens because of the super narrow depth of field.

Also, I think the minimum focusing distance of 40cm caused me to inaccurately judge how the Sigma was focusing. Live view with focus peaking helped me identify how the focusing was behaving at close distances, which helped me when doing the testing. The Sigma still doesn't focus well at infinity for some reason, and the focus ends up hunting a bit more in general, but it's nothing that I can't get used to.

I guess I was more upset at the fact the new lens I bought was sitting in my bag on my holiday because I didn't have time to properly test it and get used to it. As such I will make sure the Sigma gets its fair shake and perhaps use it for a monthly challenge to force me to really get to know it in and out. In the worst case scenario that I can't get it to work for me, I'll just resell it at a small loss to another member.

[Na Horuk]

Well hey, no worries, we just all hope our equipment will be stellar and are upset when it isn't. Finding out how to use it better and adapt to its limitations is usually the best and cheapest way to go Happy shooting and enjoy your triangular bokeh

[Paunel]

My experience with Sigma lenses? From about 1/2 year the marvel, Sigma 17-70mm/f2.8-4 HSM non OS is a perfect one lens (I had post my good impressions about at its place, immediate followed by 2 bad impressions for lowering the score (yes, this is a Penty place, don-t lower this marvel )). My second impression is with Sigma 30mm/f1,4 for Penty (K5, ehehe- Silver but with pearls on the sensor ). This one need +2 fine focus adjustment to be a perfect one from f1.4. But this perfection is erratic, about 15-25% of photos had spurious focus, not in zones of my expectations. Hellas, I want-t to send it back! But I-m not a pro and this perfection blur and sharp from f1.4 and exquisite from f2.0 make me hesitate. And I re-discover Live View and this made from this lens, a perfect one, and I don-t need FA 31mm. But retain, I have the marvel FA 77mm/f1,8 and this one is not more sharp (only more contrast-but this can be improved in p.p.) at f1.8 face to Sigma 30mm at f1.4. The ratio quality/price is unbeatable on this lens and the new (superficial=cosmetic) line of Sigma lenses had one single intention: the rise of prices. I give up to Pentax lenses (new, but now even the old ones have a new up-price) and I have migrated to this Sigma lenses. Now, by-by, all Penty and Sigma lenses. My Sigma 17-70mm and Penty 55-300mm covers all my daily needs. And for the cat eyes I have Voigtlander 58mm/f1.4(manual focus) , Sigma 30mm/f1.4 and Penty FA 77mm/f1,8. There is enough subjects to explore with this technologies in an entire life. If this toys can leave with me, but I don-t think so.