help! stuck aperture blades

was using my sigma 70-200 halfway when the aperture blades got stuck! so now all I see is a dim viewfinder. I tried to set the aperture to the smallest and use the DOF preview button to hopefully make it unstuck but doesnt work. When I release the button, the blades retract but don't open up fully. The extent to which they open to is also different.

Any suggestions to remedy it? Or do I just have to send it to Sigma for repair? If so how much would it cost?

Welcome to sigma quality and value. Simply said I also had the same think happen to my 17-35 HSM EX F2.8 and it was under warranty. I sent it in 5 times to get it fixed correctly then sold it off. I have the canon 17-35 F2.8 L for over 2 years and no problems to date and the lens really gets a work out with my digital cameras. To date non of my canons have ever failed. Did I pay more yes is it worth the price yes it is no problems and some area over 8 years old. Any one with a old sigma need to send in there lenses so they can now work with the new digital body’s what a pain in the #@!&*#. There is no value in sigma lenses they are not as good as canons by far.

I am really getting sick of people talking about how great Canon lenses are versus Sigma lenses. You know some poeple simply cannot afford L glass and also want to have a 2.8 aperture.

Since I, and others, do not have an extra couple grand laying around for lenses we have to use other outlets like Sigma.

Thank God for warranties. I have my 100-400L lens down in Irvine for repairs so L glass is not perfect either. Send it to Sigma. They're a decent company and stand behind their products. In bteween my L glass I still have a 70-300 Sigma and it does a decent job. It does not come close to L glass build and quality, bit it gets the job done.

I hear ya..

Littlebike wrote:
I am really getting sick of people talking about how great Canon lenses are versus Sigma lenses. You know some poeple simply cannot afford L glass and also want to have a 2.8 aperture.

Since I, and others, do not have an extra couple grand laying around for lenses we have to use other outlets like Sigma


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Well said. All I can say is Sigma repaired a dropped out of warranty 170-500 as a coutesy, Canon chahged me $120.00 to repair an in warranty broken 550ex they said I mishandeled.

This sort of thing can happen to ANY manufacturer, whether it be Canon, Sigma, BMW or Kia Motors. It's a mechanical and electronic device for god's sake! They all will break down at some point. Some will go on for years without you even thinking about it.... and sadly some won't. You're just unlucky mate. Sigma is a big big company who ship out thousands of lenses every day. They make a range of quality glass affordable to people who cannot afford marque lenses. I myself have a 70-200 EX 2.8. This is a fabulous, sharp lens. I couldn't afford the Canon version, and wanted a wider aperture than the f4 Canon equivalent. I have just bought and returned a Canon 17-40 f4 L. It was very soft at 17mm at all apertures. I'm waiting for a replacement at the moment. So you see, even the odd one slips past the mighty Canons quality control. P.s...I don't work for Sigma!

I might add that it is highly possible for any lens to fail at any point in time, for reasons that we will never know.

However, it has been my experience that the majority of lens problems can be traced to some type of abuse, even if minor. For example, if rain gets inside the lens, if it gets bounced a little too hard, or if the lens got jerked with respect to the camera body... all of those things can lead to a failure pretty soon.

I had an excellent f/1.4 lens on an excellent body. It got soaked in water, then frozen, and then thawed and left out. The body was history, as you would imagine (unrepairable). The lens came through it fine once it was placed on a new body.

---Bob Gross---

sigma/canon

I'm not an "L" glass junkie, but my experience with Sigma has been poor. My experience with Canon lenses was MUCH better, but I'm still upset with canon on the last repair I had done.

YMMV right?

-Pete

Pardon my ignornace, what does YMMV mean?

Look at the bottom of a new car ad. They will quote the city and highway gas mileage, and then state "your mileage may vary".

In other words, what was just stated is not a guarantee of anything.

---Bob Gross---

before AM GENERAL and US ARMY came up with the acronym for their HMMWV (High Mobility Multi purpose Wheeled Vehicle), the test name was YMMV...

Y our
M ileage
M ay
V ary

Gotta agree, glass snobs suck.

Off topic (good luck on the aperture blades!), but how do you guys like the Sigma 24-70mm f/2.8 EX Aspherical DF? It's definitely cheaper than the Canon L, but the main attraction of the 24-70L is that it's pretty darn sharp right down to f/2.8. Can you say the same about the Sigma? It's pretty tempting. I don't care much about weatherproofing and that fancy red stripe. Just image quality.

I have that lens and really like it a lot, the areas that were in focus are very sharp. My canon has a focusing issue so what I have been aiming at is not neccesarily in focus but stuff just behind of in front was, and was very sharp.

Of course Canon blamed my issue on the lens and I heard a long diatribe about knockoff lenses to which i responded, when you make a 24-70 f2.8 for under $800 I will buy it, untel then, I will not be buying Canon zooms. The lady on the other end of the phone was very upset.

In the end, I did some test shooting with a Canon lense and the problem was even more pronounced.

sorry to go off subject like that.

Very true I have also tried sigma time and time again and have had way to may of them fail in the field. I have stopped buying sigma and the only sigma I have is the 105 F2.8 Macro with is a Razor sharp lens. Mind you this is the only sigma I have ever had witch is this sharp. Also you cannot even compare the canon 24-70 F2.8 L with the sigma in the same focal range at all. They are not even in the same class of optics or quality. Sigma is not a bad brand. It just is not in the canon "L" class of lenses. Why do you see so many pros using "L" glass not because they are snobs? They know what works "L"s can take the abuse of ever day use. If you do not use your gear ever day then sigmas will work for you. But if you are a pro and can not second guess if the lens will cause and error on your high end digital SLR of if it will fail then sigma is not for you. Truth told time is money and most of us cannot afford to miss that all-important shot. I am not a snob just a person who has used sigma’s for the last 10 Years and have had way to many problems and that’s a fact. Good luck to all of you and the 105 F2.8 Macro is a wonderful lens. I love it but the A/F is way slow over my canon 50 MM macro but I can accept that, as I do not need a fast A/F for macro photography. Truth the sigma is sharper than my canon 50MM macro.