Would it be possible to program the camera with two MFA adjustments for the lens, one to be activated under studio lights and another for outdoors? Seems like there should be a way to do that.
Because honestly, it does not seem like a lens "issue" per-say... Just a trait with its compatibility with the Canon bodies. I am sure with Sigma bodies, or even Nikon possibly, that my lens would not have this "trait".
I use my Canon 35 1.4 wide open all the time and I have to use +3ma for one shot mode and -3ma for servo mode. Because of the really wide aperature the small ma adjustment makes a big difference in capturing the proper elements within the focus plane. It's a pain, but the lens has been back to Canon a couple of times and it's very good as long as you use these two ma settings. Like the song says, "Getting to know you" definitely applies to our lenses. I've had this 35 1.4 for four years and because of learning curves and other technical problems I am just now able to get exceptionally good, consistent results with it. I would not want to start this process over again with a Canon product or any other brand. I'm happy for all of the people who get a 35 1.4 and get great results with it straight from the box. You don't know what you're missing!
For what it's worth I'm returning the Sigma 35 (#2) and I've purchased a 35 L.
I'm quite sure the Sigma is sharper wide open, but IMO if you have front/back focus issues it's just not worth it for me.
I'd rather just use the Canon at F/2 and get arguably better colors and bokeh with more accurate focusing. I picked up a 35L for under $1k.
Jan 13, 2013 at 07:10 PM
Lars Johnsson Offline • • • • • • • Upload & Sell: Off
I have mine boxed up already with my camera and dropping it off tomorrow afternoon at the post office to be sent to the sigma service center in NY. Anybody know what the turnaround times are like for lens calibration?
RogerC11 wrote:
I have mine boxed up already with my camera and dropping it off tomorrow afternoon at the post office to be sent to the sigma service center in NY. Anybody know what the turnaround times are like for lens calibration?
I have no idea, but please update the board on how this goes...
trenchmonkey wrote: Lars is a great photographer...and doesn't blame his equipment. Just sayin'
That's completely uncalled for. No one was saying Lars wasn't a good photographer, nor was I blaming one single lens for any problems I've had in photography. 25% of the poll does state there are issues with this lens. Are you saying a quarter of us who have reported problems are merely "blaming it on the equipment"?
Also, I cannot vote again in this poll for copy #2, so is this completely accurate?
My 135 L, 85 1.8, 70-200 F/4 and 24-105 aren't giving me front/backfocus issues.
trenchmonkey wrote: Lars is a great photographer...and doesn't blame his equipment. Just sayin'
The AF problems are real. However, unlike some of the people in this thread, I'm taking proactive steps to getting the issue resolved. Like I stated already, the lens and camera are heading off to sigma tomorrow for calibration. I really do like everything about the lens and it could only be better if the AF works. Yes it works on YOUR camera body and that's great. I'm truly happy for you. Unfortunately this isn't the case for everybody and especially in my case since my camera doesnt have the MA feature for tweaking AF. But please don't downplay the reality of it with snarky unhelpful remarks.
RogerC11 wrote:
The AF problems are real. However, unlike some of the people in this thread, I'm taking proactive steps to getting the issue resolved. Like I stated already, the lens and camera are heading off to sigma tomorrow for calibration. I really do like everything about the lens and it could only be better if the AF works. Yes it works on YOUR camera body and that's great. I'm truly happy for you. Unfortunately this isn't the case for everybody and especially in my case since my camera doesnt have the MA feature for tweaking AF. But please don't downplay the reality of it with snarky unhelpful remarks. ...Show more →
Yes AF problems are real. But every lens will have AF problems in a poll like this. And it's also a combination of lens and camera. And even with the perfect combination of lens and body, you will never get perfect AF on every shot you make. Just like you will never get perfect exposure on every shot you make. but people don't complain about the exposure at all. (not talking about you) but many people here belive that they should have 100% or close to that with perfect focus when they aim the camera and AF point on something. Every camera and lens has their strong and weak points. And the most important thin is to learn about the equipment. And then use the weak and strong points to your advantage. No lens will give you 100% in focus shots every time you use it
Lars Johnsson wrote:
Yes AF problems are real. But every lens will have AF problems in a poll like this. And it's also a combination of lens and camera. And even with the perfect combination of lens and body, you will never get perfect AF on every shot you make. Just like you will never get perfect exposure on every shot you make. but people don't complain about the exposure at all.
Who's complaining?
Jan 13, 2013 at 10:14 PM
Lars Johnsson Offline • • • • • • • Upload & Sell: Off
Lars Johnsson wrote:
Where did I write that someone is complaining
From your ORIGINAL post it seems that you were sarcastically referring to someone in the thread just as trench monkey was but I also see that instead of editing his post or apologizing, he just deleted. I completely understand that theses are just machines and no machine will be perfect but they are built to perform to a certain specification and when those specifications arent met, some kind of correction must be made whether it be MA or lens calibration by the manufacturer. Im not blaming Sigma as a lot of people like to do, I'm also not a canon fanboy so instead of preaching off bad sigma qc or canon superiority, I'm sticking with it until it gets fixed because I love the lens. Keep in mind Im still under BHphoto return period and could just as well have "exchanged for another copy" or refunded to but a 35L instead. I've had the 35L before and quite frankly, this sigma is the better lens.
Here is some more information about my artificial light front focus issue... Much like what Roger has stated... The Sigma just may not be well corrected for this with the Canon AF system and would happen with every single Sigma 35... Not copy variation. But due to the different AF systems, it may or may not affect certain bodies I would think... But this would explain why taking an identical picture in the same room at the same distance changes MA value when it is natural light vs compact fluorescent lighting.
New in the Canon EOS 7D is a feature that tweaks the behavior of the AF system based on color information from the new color-sensitive exposure sensor, reducing AF problems often encountered when shooting under artificial illumination. Canon staff told us that back-focus errors can relatively common under artificial lighting, particularly in stadiums or other sporting venues. Canon didn't go into details of why this might be the case, or what specifically they did to correct it, but it's not too hard to figure out: Without special correction, a lens system will bring different wavelengths of light into focus on different planes. High-quality camera lenses are usually well-corrected apochromats, so this isn't a problem at the image sensor. The relatively simple optics (lenses and prisms) in AF systems are another matter, though, so it's very likely that long (red) wavelength light would produce a different focus point than would short (blue) wavelength illumination. By taking the color of the light source into account, the camera can compensate for this tendency, in much the same way that it can handle micro focus adjustments for different lenses.
Lars Johnsson wrote:
Yes AF problems are real. But every lens will have AF problems in a poll like this. And it's also a combination of lens and camera. And even with the perfect combination of lens and body, you will never get perfect AF on every shot you make. Just like you will never get perfect exposure on every shot you make. but people don't complain about the exposure at all. (not talking about you) but many people here belive that they should have 100% or close to that with perfect focus when they aim the camera and AF point on something. Every camera and lens has their strong and weak points. And the most important thin is to learn about the equipment. And then use the weak and strong points to your advantage. No lens will give you 100% in focus shots every time you use it...Show more →
These types of posts...I don't know what to say. Please don't talk to me like this is my first camera. You can't really think we don't already KNOW that every shot isn't going to be 100% in focus, or that we'll get perfect exposure every time.
But I should be able to set up a static object indoors and out, and with a tripod + remote release and 5 tests shots get at least 1/5 in focus right?
Lars is a great photographer...and doesn't blame his equipment. Just sayin'
And the same have been the case for most people here