New 50mm, Bad Copy. Return or Warranty?

I just got my new Sigma 50mm f/1.4 in the mail. I took over 100 test shots, and was underwhelmed with the performance. It is softer than my nifty, even at f/1.8 on both. (I looked at f/1.4-> f/8 on the siggy) Additionally, I notice heavy CA on any highlights (green or purple, depending on position relative to the focal plane), as well as ghosting on anything bright / high contrast. I took all my test shots indoors, and compared them with results from my nifty as a sanity check. I looked at handheld, tripod mounted, live view focused, focus microadjusted, etc. on my 50D.

I love the build and feel of the lens, I just want one to give me the results that I have been hearing about.

Now I am trying to decide...return it to B&H for a refund/exchange, or send it in to Sigma for warranty work. Third option, tell me I'm crazy and that an f/1.4 lens is a different animal and that I should expect a learning curve.

I feel like the B&H route might be faster, but expose me to another "bad copy" while the warranty route might be a bit less expensive (is shipping cost covered under warranty?) and might give me a better chance at getting a lens back that is performing well, but it might take longer. Any thoughts?

How are you testing focus? Indoors, you already said. Shutter speeds? ISO? It's 2/3 stop faster than the nifty, so yes, there is a learning curve.

It's supposed to be a good lens, if you get a good copy. If you don't, it can be the "send it to Sigma, hope it's good when it gets back, send it out again because it isn't" dance.

I've had one Sigma, my 10-20, and it's a sharp copy, but it isn't complained about like the 50/1.4.

Just save up for a 50L.

Brett wrote in post #7553275
Just save up for a 50L.

This.

Make sure you are using a high enough shutter speed and Single Shot AF. Use Tripod + MLU + timer on a hard surface with a good tripod etc and shot a focus chart.

I was fairly happy with the focus of mine on people in real life situations. Just a bit soft but I wasn't happy as I was expecting more. I have sent mine in to Sigma for focus calibration (I have a 1015xxx serial lens) as the focus chart showed consistent backfocus. They now get back to me saying that they need to replace the main CBA (I'm guesing Circuit Board Assembly) for it to focus correctly! It will take 4 weeks or so they say as they are waiting on the parts. I am assuming something changed between the time my lens was made and now or the damn thing is already broken (Though it does seem to work well).

Brett wrote in post #7553275
How are you testing focus? Indoors, you already said. Shutter speeds? ISO? It's 2/3 stop faster than the nifty, so yes, there is a learning curve.

It's supposed to be a good lens, if you get a good copy. If you don't, it can be the "send it to Sigma, hope it's good when it gets back, send it out again because it isn't" dance.

I've had one Sigma, my 10-20, and it's a sharp copy, but it isn't complained about like the 50/1.4.

Just save up for a 50L.

I am using liveview, on a tripod, both using the contrast detect focus and manually focusing at 10x magnification. Shooting lights, for example the clock on my stove, I am finding that I have to stop down to f/2.8 or so to avoid blooming. My focus tests for shutter speeds have been 1/100 or faster, and using ISOs of 400 and lower.

As for the 50L, my first thought was "I wish". There are plenty of other L's on my shopping list, too! (I keep telling my wife that a $10k gift card to B&H would get me "about 70% there." So far, no $10k gift card, but I'll keep dropping hints.

Brett wrote in post #7553275
How are you testing focus? Indoors, you already said. Shutter speeds? ISO? It's 2/3 stop faster than the nifty, so yes, there is a learning curve.

It's supposed to be a good lens, if you get a good copy. If you don't, it can be the "send it to Sigma, hope it's good when it gets back, send it out again because it isn't" dance.

I've had one Sigma, my 10-20, and it's a sharp copy, but it isn't complained about like the 50/1.4.

Just save up for a 50L.

JAcosta wrote in post #7553286
This.

MadTony wrote in post #7553480
I am using liveview, on a tripod, both using the contrast detect focus and manually focusing at 10x magnification. Shooting lights, for example the clock on my stove, I am finding that I have to stop down to f/2.8 or so to avoid blooming. My focus tests for shutter speeds have been 1/100 or faster, and using ISOs of 400 and lower.

As for the 50L, my first thought was "I wish". There are plenty of other L's on my shopping list, too! (I keep telling my wife that a $10k gift card to B&H would get me "about 70% there." So far, no $10k gift card, but I'll keep dropping hints.

Why would you want to do that, the 50L has a design flaw meaning it will always have a focus issue. Search these forums for more details.

Pictures of the test shots with EXIF or it did not happen.

I haven't been satisfied with my 50 1.4 USM and I proceeded to buy the EX 1.4 after reading so may positive reviews.

First copy was really bad that nothing below f/2.8 was usable. Brought it back to the shop and they gave me another brand new copy. It was slightly better than the first one but still performed badly compared to the 1.4 USM.

Ended up returning it again and this time I'm going for 85mm 1.8. The shop had heard some complaints about the green glow/fringe issue when used wide open ... Apart from that my copies had AF problem as well .. and it sounds so awful when you use AI Servo .. i think Sigma didn't design for this lens for continuous focus ..

Assuming you have been getting good results with the 50/1.8, I doubt it is human error. If you are getting ghosting/blooming then have it repaired.

I am of the opinion that a lens actually fixed/calibrated individually should guarantee that it is working as best as the lens can, as opposed to coming off a shelf and, maybe being, 90%.

I had a similar issue with my Tamron 28-75. It was extremely sharp wide open at all apertures, except for inconsistent focusing and blooming at 75/2.8. I decided to send it in to Tamron rather than having it replaced, in case I got a replacement that focused well, didn't bloom but was not quite as sharp. I made the right decision. Very happy with the results after Tamron worked on it.

I sent mine into Sigma for repair and I had it back in less than 1 week (minus transit time for shipping).

My lens front focused enough that i couldn't microadjust to fix it. The new one still front focuses at the MFD that can be overcome with microadjust now however if I adjust for the MFD, at longer distances, the lens tends to backfocus (due to the microadjustment).

I love the 50. I get green fringing at f/1.4 but only when shooting white objects against dark objects.

KarlosDaJackal wrote in post #7554052
Why would you want to do that, the 50L has a design flaw meaning it will always have a focus issue. Search these forums for more details.

Pictures of the test shots with EXIF or it did not happen.

Yeah, I know. It was a play on those who constantly recommend L primes to people who are looking at a $500 lens.

The other thing is, I want a 35L/50L/85L/135L/200L lineup...someday.

I sometimes disagree using tripods. The reason is you will NOT be running around taking photos with a tripod in real life. Use the tripod for supplemental testing to accurately see if theres front/back focus. Thing is if your taking photos of a child/person as a test subject one of the variable moves

Take many photos as "usual" and do your testing.

I feel its a gamble sometimes taking a copy and sending it to sigma. Try your absolute best to get the great copy straight out of the box. Easier said than done.

Wideopen performance is obviously important but I find for sharpness/resolution f/1.8 to f/2 is great (canon 50 f/1.4) . With the 5d if the eyes are off the plane you'll just get a "single eye focus shot".

I just dont dare to buy the sigma 50mm just yet. The copy I had was barely acceptable at f/2.8.

KarlosDaJackal wrote in post #7554052
Why would you want to do that, the 50L has a design flaw meaning it will always have a focus issue. Search these forums for more details.

Pictures of the test shots with EXIF or it did not happen.

Have you owned the lens or are you just going by the complaints on this board which represent .1% of the total owners out of the lens?

I dont have a focus shift issue, and there are others who dont either.

The 50L has the same blooming on super high contrast transitions at really wide apertures, so you won't get any improvement there, and the green/magenta longitudinal CA is actually worse on the 50L. If you get a good focusing copy of the Sigma, it's at least equal to the 50L in image quality, and I find mine far better than the canon 50 f/1.4, especially in the bokeh deparment.

JAcosta wrote in post #7555622
Have you owned the lens or are you just going by the complaints on this board which represent .1% of the total owners out of the lens?

I dont have a focus shift issue, and there are others who dont either.

Congratulations to you and them!

Used yes briefly, owned nope, unfortunatly for Canon, I try before I buy and am not blinded by red rings The one I used had an issue the owner was unaware off. I didn't point it out to him as ignorance would appear to be bliss and I have no need to rain on his parade, maybe you are the same as him and I'm cool with that. Local stores don't carry it "anymore" and will only order one if I am buying in blind fate and give a deposit.

The complaints here are valid, most have had many copies and decided to "settle" on one that also had the issue to some extent. I dispute the made up .1% figure and instead will include the lensrentals.com 13.3% calibration issues figure. Thats more issues than the notorious Sigma 30mm f/1.4 for Canon's flagship standard prime! Ouch. You can't ignore that even if your copy works for you.

Roger from lensrentals did a write up on the page for the 50 1.2 L and I think he probably has access to more copies than anybody. I'll paste the quote here for convienence
"

• If you’re not used to working with very narrow depth of field (f1.2 close up is NARROW) this lens will take some practice. Use one autofocus point only or it will focus where it pleases, not where you want.
  
• The plane of focus is not flat, its slightly curved. Focus-recomposing will guarantee you an out of focus shot. Just don’t do it.
  
• The 50 f1.2 exhibits focus-shift for near distance shots, meaning that shooting objects a few feet away between f2 and f4 the lens will probably not autofocus accurately. At f1.2 its accurate, and by f5.6 the depth of field is wide enough that you won’t see the effect.
  
• The 50 L is camera specific: that is a copy that is wonderful on one camera may backfocus on another. Its best used, for that reason, on cameras with focus adjustment like the 1D series or the 50D."

I guess the Sigma is really the least of the evil of the bokeh machines. Bokeh is great with high potential of focus issues. If the sigma 50 f/1.4 had rock solid AF that would be the death of the 50L to a high percentage of people that do not require such fast glass. F/1.4 seems plenty fast for my purposes if not its still too thin DOF for my application.

The Canon 50 f/1.4 is the consumer grade lens that is still hard to beat for versatility of f/1.4. My nifty was phenominally sharp at f/2 to f/2.2 with not so desireable bokeh.

Sigma......please fix your problems!!!