50mm f/1.4 shooting advice

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danski

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So I've bought the Sigma 50mm f/1.4 lens, now I'm struggling to get good shots with it. :help: I have no doubt that user error is probably more to blame than the lens (despite nearly everyone thinking they've got a bad one!), so looking for some shooting advice/tips please.

I have already micro adjusted it on my 7D (needs -5) and seem to get consistently in focus shots if I shoot static objects using a tripod, but I struggle when shooting other more interesting objects, whether it be nature or portraits, with them mostly being out of focus.

Now I appreciate that f/1.4 will give a very small DoF and if the object of focus moves, then chances are it won't be in focus, even if I use AF Servo rather than One Shot for focussing. I have found that stopping down to f/2.8 I get better results, but that's not the point of having an f/1.4 lens and I do want to get the creamy bokeh from shooting wide open.

I have also found that sometimes I get random forward/backward focusing - unfortunately I've deleted any pics where I had this, so can't upload one. I can however remember one where I was taking a pic of a mate (who was stood still) from about 10m away (probably f/1.4) - centre focus point was on him, but the trees approx 10m behind him came out in focus when I downloaded the photo - he was clearly out of focus. Think this was before I had micro-adjusted, but surely it wouldn't have been that far out? On the same day I took about another 200 pics with the same lens (I was at a wedding) and well over 60% of the others came out OK - some OOF ones were clearly down to alcohol consumption! :bonk:

So is it user error at fault? If so, please give me some shooting tips (other than "stand still and make sure your subject is still!"). If it's the lens at fault, then the Sigma warranty should sort it. My guess is the former. :amstupid:

thanks as always
 
When you say out of focus..... :shrug:

It can look horrendous viewed at 100% and still produce a really sharp looking A3 print.
Assuming the softness you refer to is when viewed at 100% you need a tripod, mirror lock up, cable release and manual focus for consistently sharp images viewed at 100%.
Print at A3 and see how it looks - it's probably going to be fine.
 
Sounds like user error. And alcohol abuse.. ;) Even the shot of your mate is very unlikely to be the lens - it's just that you've let the AF point slip on to the background.

If it's any consolation, shooting anything that moves at f/1.4 is very difficult at the best of times. Use all the tricks, single-point AF, servo, beware of focus-recompose issues which in really close shooting situations is guaranteed to throw the focus out (google that one). Practise lots, shoot loads to increase your hit rate, and be prepared to bin plenty.

Need to post a pic for specific advice, but it sounds like your lens is fine :) .
 
I have this lens, it's a great lens IMVHO.

I only use centre spot or manual and have no real problems but you do have to watch your shutter speed and not let it fall too low. I try to keep it towards if not into three figures.

Also when shooting subjects that are closer at wide apertures it's important not to nod or sway even ever so slightly forward or back as you take the shot and also make sure that you're focusing on a subject that actually has enough detail for the camera to lock on to especially in lower light.
 
I've got the Canon version, and can safely say it's one of the trickiest lens to get spot on shots straight away.

But when you do....

:love:
 
Remember this lens is not tack sharp throughout the frame when wide open, so I usually stop down by a stop or so to improve IQ and give a little bit more DoF to play with, unless it's really low light levels and I have no choice. You can still get good bokeh at f2 :-)

Remember to nail the focus on those eyes as well.
 
I usually dont even bother with 1.4 on my canon 50mm its just to shallow DoF, focus recompose slightly and its lost.

I find 2.0 plus is generally better but if your after 1.4 shots i would recommend tripod and manual focus/live view if you're not to good at manual and use the 5x/10x zoom.
 
minky_monkey said:
I've got the Canon version, and can safely say it's one of the trickiest lens to get spot on shots straight away.

But when you do....

:love:
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I don't know, but for me it works extremely reliably so far. I stop it down to f/2.0 + to get more contrast, and it's nearly always spot on. If it isn't there is something wrong somewhere - AF, calibration, or lens itself. At this point you should look for centering defects (sides and edges may appear inequivalent in various ways, good centre is only part of the game) - and if you find - back it goes.

Canon is built like a toy, and Sigma is just problematic. I'd really love to mount Nikon glass with full AF.
 
Cheers for that, I'll go back and have another go. I must admit, I haven't played with the micro adjustment yet either.
 
danski said:
I have also found that sometimes I get random forward/backward focusing -
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If the lens was faulty you'd get one, or the other but not both. It sounds more like you're just expecting too much from the lens.

As other posters have said, due to the wafer-thin dof at f/1.4 any movement be it either the subject or the shooter, can render a shot oof and the fact you're experiencing both front and rear focussing suggests this is far more likely to be the cause than any fault with the lens....
 
daugirdas said:
At this point you should look for centering defects (sides and edges may appear inequivalent in various ways, good centre is only part of the game) - and if you find - back it goes.
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not sure what you mean by this - what exactly should I be looking for?
 
Flash In The Pan said:
If the lens was faulty you'd get one, or the other but not both. It sounds more like you're just expecting too much from the lens.

As other posters have said, due to the wafer-thin dof at f/1.4 any movement be it either the subject or the shooter, can render a shot oof and the fact you're experiencing both front and rear focussing suggests this is far more likely to be the cause than any fault with the lens....
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I'd say that there is more of a tendency to back focus than front focus. My biggest concern was that the focus point was on my mate (who wasn't really moving & 10m away from me) but it was the trees were in focus a good 10m back from him. Surely micro-focus adjustment is just that - micro-focus. What could cause it to focus 10m behind a subject 10m away? Don't think that was user error, although difficult to confirm as the shot went in the bin, so I can't check focus point with DPP
 
It really sounds like you've focused on the background. Unless the lens is MASSIVELY out, I can't see how you could do that. I've got the Sigma 50mm1.4 and used it on a 30D and a 60D, and I've seen that happen when I've moved slightly as it's got the focus on a darker area and it's hunted a bit, then refocused.

The only way to be absolutely certain you're not doing that is to use it manually. When the subject is in focus, you're set, if it does the same again, either you moved or there's something odd going on with the lens.
 
I use to find the 1.4 lenses so difficult to get good shots on when first buying them, but now I never seem to have a problem. I love my 50mm f1.4. The Sigma is sharper than the Canon at f1.4
 
Most of these 50mm f1.4 lenses are quiet soft at 1.4 particularly away from the center of the image. If you pick a focus point thats away from the center it may have trouble focusing accurately. This coupled with the narrow depth of field makes for a low success rate.
 
I've the Nikon flavour of the Sigma 50mm f/1.4 and it works beautifully on my D700.

As with any lens, you do have to look out for tricky lighting conditions which may make it difficult to autofocus e.g. extreme conditions, very bright/dark, low contrast, sun facing, etc. Also, if you're on some form of continuous focus then you might find that some of your autofocus points cover enough area on your frame to to and fro between different features at different distances.

Make sure you use a lens hood to help prevent unwanted, stray light from hitting the glass.
 
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My depth of field calc give you around 6 feet of total depth of field at around 30 feet shooting 50mm at f1.4.

I don't have an issue with my Canon one, use it quite a lot at gigs and generally it nails it everytime. You really do just have to watch shutter speed and depth of field.
 
I actually now use single shot AF with my 30mm f1.4. I found that the servo mode was a little too unreliable at such shallow depths of field. I just take my time when shooting and make sure I am steady. However, even the slightest movement will knacker your focus! ;) I have ended up also mostly shootinig at at least F1.8 to f2 as f1.4 has a stupidly narrow depth of field and only use it when the light really needs it.
 
Lots of good advice above (I like the tip about shooting bursts, and I typically try to rock back and forth slightly when doing this). I very carefully calibrated one of my (telephoto) lenses until it was spot on using tripod, mirror lock and three different techniques, took it to a game and every shot was OOF. I reset the calibration to zero and it works fine. I'm not saying that's always going to be the case but it might be worth trying it with microadjustment off but with your normal shooting style.
 
getting slightly confused - is One Shot or AF Servo better for focussing for portraits as this is what I like to use my 50mm for? I guess One Shot is good if the subject (and me!) is still, but AF Servo might be better if snapping my 5 year old son (who is rarely still!) - but there's the risk that AF Servo searches for a different focus point (not sure if this will happen though as I tend to shoot single & centre focus point)

Also, am I better stepping back and cropping the photo rather than taking close up as this will give me a little more DoF and therefore some room for error?

I love the lens, just would love to be able to shoot better with it!
 
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Or don't step back and use a smaller aperture. It will increase your sharpness and save cropping. :)
 
Do you focus and recompose? If so, then I would suggest one shot as the AF can easily slip otherwise. If you don't recompose then I can see servo appealing, but I rarely use it for portrait work.

Expanding your dof by standing back is kind of negating the value of the 1.4. I think this is a technique issue (unless you have one of those notorious dodgy copies...) and once it clicks you will love the lens.
 
ianmarsh said:
Do you focus and recompose? If so, then I would suggest one shot as the AF can easily slip otherwise. If you don't recompose then I can see servo appealing, but I rarely use it for portrait work.

Expanding your dof by standing back is kind of negating the value of the 1.4. I think this is a technique issue (unless you have one of those notorious dodgy copies...) and once it clicks you will love the lens.
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i tend to compose, then focus and shoot in quick succession - think it might be down to moving subject as I'm fairly steady in my shooting

I'm going to practice at f/2 or f/2.8 to see if I'm getting sharper and more in focus shots, this should help to determine if it's me or the lens.

Out of curiosity, what's the best way to tell if it is the lens? Are there any 'standard' tests I can carry out to figure this out?
 
I've seen people use a Cereal box for the focus point then place a ruler at a 45 degree angle next to the box. Focus on some of the bold writing which is easy for the camera then look across at the ruler.
 
foggy4ever said:
I've seen people use a Cereal box for the focus point then place a ruler at a 45 degree angle next to the box. Focus on some of the bold writing which is easy for the camera then look across at the ruler.
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done that - that's what I did for my micro focus adjustment - mounted on a tripod and shooting many shots, they were all in focus. I didn't shoot at 100x focal length though - I would have been at about 40-50x f/l away from the cereal box
 
I've been using a 30mm F1.4 over the past couple of weeks and I find the best way to take portrate images is to use one shot, focus on the eye, and then recompose. AI servo can make the shot out of focus. Using F2 or F2.8 will only increase depth of field, it will not prove or disprove lens focus problems or user error.
 
4140133391_2319ca7e99.jpg


Shamelessly stolen from someones flickr.
 
SamP said:
4140133391_2319ca7e99.jpg


Shamelessly stolen from someones flickr.
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But you don't HAVE to take pictures like that:

Taken on a 350D using the "Nifty Fifty".
19_Sept_2009_-_1563.jpg

Taken on a 450D also using the "Nifty Fifty"
Chloe21.jpg

.
 
I've just bought the Sigma 50mm 1.4.
The first one went back because it was front focussing, & the second one I had to MA to +19. And its still a bit squiffy untill you got to about f2.2.

Still unsure as to keep this lens.:shake:
Could really do with comparing it to a sharp one!!

BTW. I rang Sigam Uk, who told me that they will calibrate it to my camera foc.
As long as I pay the postage to send both lens & camera. (take approx 2 weeks):bang:

Spence
 
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