Just got my Sigma 30mm (focus test inside)

Looks like front focus to me

HTTP response: 404 | Byte size: ZERO

HTTP response: NOT FOUND | MIME changed to 'image/gif' | Redirected to error image by FLICKR

What do "real word shots" look ike?

I just walked around my apartment, I have a few more coming.

It seems like about 1 in 10 shots will hit correct focus

Focus point was center on all of these

HTTP response: NOT FOUND | MIME changed to 'image/gif' | Redirected to error image by FLICKR

HTTP response: NOT FOUND | MIME changed to 'image/gif' | Redirected to error image by FLICKR

HTTP response: NOT FOUND | MIME changed to 'image/gif' | Redirected to error image by FLICKR

HTTP response: NOT FOUND | MIME changed to 'image/gif' | Redirected to error image by FLICKR

can the 40D do MFA?

lens looks like its front focusing....see your jacket is in focus rather than your finger im assuming you were focusing on the finger.

Well I definitely think this lens has a tendency to miss and front focus a bit. But it might be a little bit of user error too.

I just took another set of the hand shot and everything is in focus just fine at f/1.4. Tack sharp a f/2.0.

Its more inconsistent than anything.

I can't tell from these shots, but are you watching the MFD? It's somewhat long for a 30mm.

tkbslc wrote in post #11138291
I can't tell from these shots, but are you watching the MFD? It's somewhat long for a 30mm.

Yeah, I was trying to.

The focus test sheet was like RIGHT at the edge of the MFD. Some of the outdoor shots are also pretty close. Perhaps that doesn't help my issue.

I just took some shots of my remote control at a more standard distance and the focus hit the button every time. Like I said, slight inconsistency and some user error.

May want to give it some more time with real world shooting before making a definite conclusion. Also, f1.4 is not suitable for every shot. Honestly shooting a branch of leaves at f1.4 I would not expect much to be sharp. I shoot my Sigma at f2 more often than f1.4 for DOF reasons alone (plus the lens gets REALLY sharp around f2)

tkbslc wrote in post #11138396
May want to give it some more time with real world shooting before making a definite conclusion. Also, f1.4 is not suitable for every shot. Honestly shooting a branch of leaves at f1.4 I would not expect much to be sharp. I shoot my Sigma at f2 more often than f1.4 for DOF reasons alone (plus the lens gets REALLY sharp around f2)

Yeah, I agree with that. I put it on 1.4 just to test the focusing. But I realize I'm probably pushing the limits.

Yes, at 2.0 this thing is razor sharp

I just got a Sigma 30 myself and was worried from all of the discussion on focus. Took some test shots that were not really sharp -- I have a lot of experience with DOF though and determined it was my techique -- so went back to some of my techniques from my "film Canon F-1/50mm" days and shot a series with great results. I then let a friend who shoots dog agility professionally use it for a weekend -- he had great results and is actually buying a copy for himself. So I'm happy and staying away from the focus charts Hopefully you'll prove that yours is doing fine, from your last post it looks that is likely.

dnauer wrote in post #11138539
I just got a Sigma 30 myself and was worried from all of the discussion on focus. Took some test shots that were not really sharp -- I have a lot of experience with DOF though and determined it was my techique -- so went back to some of my techniques from my "film Canon F-1/50mm" days and shot a series with great results. I then let a friend who shoots dog agility professionally use it for a weekend -- he had great results and is actually buying a copy for himself. So I'm happy and staying away from the focus charts Hopefully you'll prove that yours is doing fine, from your last post it looks that is likely.

Yeah, the more I think about it the more I think I'm jumping the guy from other conversations about issues with this lens.

- this is my first prime
- first time with an aperture wider than 2.8
- first time using my 40D

I think there are a lot of things going on and I need to blame myself. I was also pushing the MFD a little to much.

Just stuck it on a tripod and suck my thumb out well in the focus range and it was super sharp at f1.4 and unbeilevable at f2.0. I'm getting the hang of it. Like said above, I can't always shoot at 1.4 anyways, im pushing the limits.

This is a fantastic lens and a great intro for primes.

Stay away from charts unless you are really "seasoned" at testing. There are just too many variables involved that can result in inaccurate findings. Simply go and shoot hundreds of frames. You will know what's up after a while.

Here's a close crop from my thumb shots. I don't know how to do a 100% crop correctly lol

f/1.4 focused on my first knuckle

I'd still get it calibrated if your keeper rate is low. I shot over a 1000 shots with my 85mm 1.8 before I decided to have it calibrated, oh boy did the keeper rate go up after calibration. My focus chart looked pretty much like yours, it was front focusing. I can't stand it if a fast lens isn't focusing correctly. I get it the AF can pick up on eye lashes etc when shooting people, it's just user error but in the long term it's got to be reliable.

try shooting a flat surface on the wall for instance and check focus compared to live view contrast detection.
here's my unscientific example before calibration