Sigma 50-500 expecting to much?
Discussion
I have had the sigma for a little while now and cant shake a nagging feeling that shots aren't as sharp as I would like, but then is it too much to expect to have clear close up crop images of birds when your at 500 zoom and haven't paid £10k for the lense. So what do you guys think is this an expected result from a sigma 50-500 at Focal length 500, F8, shutter 1/500, iso 200 on a canon t2i(550d)?
Is it me doing it wrong, expecting too much or do I have a duff one?
thanks
overall pic to show scale etc
Close up
Is it me doing it wrong, expecting too much or do I have a duff one?
thanks
overall pic to show scale etc
Close up
I'd suggest you start by trying to shoot a static target on a tripod and see how you go from there.
It's possible to have a large print made from a shot from a 400mm lens (I've done that a few times, although the official Canon lens) at 400mm, but I'd start with static fixed images and go from there.
It's possible to have a large print made from a shot from a 400mm lens (I've done that a few times, although the official Canon lens) at 400mm, but I'd start with static fixed images and go from there.
Could you show us some other crops of other parts of the bird?
Does it look like you missed focus on the bird's head and got it elsewhere on the body?
I agree about the shutter speed. I would be wanting a shutter speed of at least 1/1000 for a moving subject at that focal length (I am not an expert).
Does it look like you missed focus on the bird's head and got it elsewhere on the body?
I agree about the shutter speed. I would be wanting a shutter speed of at least 1/1000 for a moving subject at that focal length (I am not an expert).
There is a rough rule of thumb that says focal length should ideally be x2 focal length and that the minimum should be x1 focal length. This originates from film cameras, i.e. 35mm. Some will tell you that for the minimum you should multiply out the crop factor - this means you should be at 1/800th for that image as a minimum.
It all gets hazy past that - I think people have interpreted it their own way and have made their own rules, for example some say IS means you can take 2/3/4 stops off the "ideal".
Of course rules are there to be broken but I'd agree that shutter speed was probably a bit low - 500mm is a long way!
I've got a 100-400 and have had similar problems when I've dropped shutter too low. Drop aperture and/or up the ISO. If you expose to the right the noise from increased ISO shouldn't be a major problem.
The other possibility is missed focus, what focus mode were you in ?
It all gets hazy past that - I think people have interpreted it their own way and have made their own rules, for example some say IS means you can take 2/3/4 stops off the "ideal".
Of course rules are there to be broken but I'd agree that shutter speed was probably a bit low - 500mm is a long way!
I've got a 100-400 and have had similar problems when I've dropped shutter too low. Drop aperture and/or up the ISO. If you expose to the right the noise from increased ISO shouldn't be a major problem.
The other possibility is missed focus, what focus mode were you in ?
Crafty_ said:
It all gets hazy past that - I think people have interpreted it their own way and have made their own rules, for example some say IS means you can take 2/3/4 stops off the "ideal".
IS helps when photographing static objects, and to a very small extent panning if the lens has a panning mode, but I wouldn't rely on it to shorten shutter speeds on moving subjects like birds in flight.Thanks, I'm happy for it to be me as I can hopefully change that, I'll try some of the suggestions above later as the light here isn't the best at the moment.
I had been going with the 1/focal length rule, but I guess that is the minimum, and was trying to avoid a wide open aperture as I had read that can be a problem with the sigma also.
I had been going with the 1/focal length rule, but I guess that is the minimum, and was trying to avoid a wide open aperture as I had read that can be a problem with the sigma also.
Agreed Mark, I think some lenses need to be static for a few seconds for IS to even work properly, so if you are panning there is no chance.
OP, as above if you look at other crops of the bird and nothing is sharp can you check the EXIF for the focus mode ?
If it was in one-shot what happened is that the camera focussed on the bird, but in the tiny amount of time between the AF locking on and the shutter opening the bird moved relative to the camera, which meant the AF lock was now invalid and a blurry picture results. You need to be in AI Servo for this sort of shot and pan with the subject during AF lock through to taking the shot and afterwards.
OP, as above if you look at other crops of the bird and nothing is sharp can you check the EXIF for the focus mode ?
If it was in one-shot what happened is that the camera focussed on the bird, but in the tiny amount of time between the AF locking on and the shutter opening the bird moved relative to the camera, which meant the AF lock was now invalid and a blurry picture results. You need to be in AI Servo for this sort of shot and pan with the subject during AF lock through to taking the shot and afterwards.
Crafty_ said:
Agreed Mark, I think some lenses need to be static for a few seconds for IS to even work properly, so if you are panning there is no chance.
OP, as above if you look at other crops of the bird and nothing is sharp can you check the EXIF for the focus mode ?
If it was in one-shot what happened is that the camera focussed on the bird, but in the tiny amount of time between the AF locking on and the shutter opening the bird moved relative to the camera, which meant the AF lock was now invalid and a blurry picture results. You need to be in AI Servo for this sort of shot and pan with the subject during AF lock through to taking the shot and afterwards.
Focus was in one shot, so will try with AI servo, thanksOP, as above if you look at other crops of the bird and nothing is sharp can you check the EXIF for the focus mode ?
If it was in one-shot what happened is that the camera focussed on the bird, but in the tiny amount of time between the AF locking on and the shutter opening the bird moved relative to the camera, which meant the AF lock was now invalid and a blurry picture results. You need to be in AI Servo for this sort of shot and pan with the subject during AF lock through to taking the shot and afterwards.
I'd start with securely tripod mounting that combination and taking shots at vertical text at, say, about 36' away (that being a distance you might expect to take bird images and get good sharp results. It's also what is often recommended for checking lens clarity i.e. around 25 x the focal length). Zoom those in to 100% crop. Are they sharp? If yes, then your technique needs some work. Even for a slow flying bird such as a Pelican I'd want to start at 1/1000 sec for 500mm and probably go faster if conditions allowed.
markmullen said:
Crafty_ said:
It all gets hazy past that - I think people have interpreted it their own way and have made their own rules, for example some say IS means you can take 2/3/4 stops off the "ideal".
IS helps when photographing static objects, and to a very small extent panning if the lens has a panning mode, but I wouldn't rely on it to shorten shutter speeds on moving subjects like birds in flight.Another thing to mention is that AFAIU, the 1/focal length rule also needs to take into account the crop factor of the camera (1.6 on a 550d). So the actual rule would be 1/(focal length * 1.6) meaning a minimum shutter speed at 500mm of 1/800.
If you want to keep f8 you should try upping your ISO by one stop to 400 and dropping your shutter speed by one stop to 1/1000 and see how you get on. Shooting some static stuff from a solid tripod is also a good idea to ensure that the lens is OK.
If you want to keep f8 you should try upping your ISO by one stop to 400 and dropping your shutter speed by one stop to 1/1000 and see how you get on. Shooting some static stuff from a solid tripod is also a good idea to ensure that the lens is OK.
f8 should give you a reasonable DOF; I think camera/subject movement is some of the issue and perhaps processing too. I'd have raised ISO and gone to 1/1000th, and looked at sharpening manually afterwards (whether RAW or JPG).
And as you say, it's not top glass so you may not be too far off the best anyway.
And as you say, it's not top glass so you may not be too far off the best anyway.
Personally I think you are expecting too much from that crop.
The camera is 18 M Pixels, thats 5184 across, you have a crop thats approx 1/14th of the total image blown up there, so you have at most 370 pixels to play with across the image. Add to that uncertain technique, one shot vs ai servo, and some unknowns like - did you have a filter on the lens? How good is that filter? Certain lenses hate filters like the 100-400mm canon.
As mentioned, try taking pictures of static items first, get the technique improved, but sometimes things are just too far away to have real detail if you crop too small.
The camera is 18 M Pixels, thats 5184 across, you have a crop thats approx 1/14th of the total image blown up there, so you have at most 370 pixels to play with across the image. Add to that uncertain technique, one shot vs ai servo, and some unknowns like - did you have a filter on the lens? How good is that filter? Certain lenses hate filters like the 100-400mm canon.
As mentioned, try taking pictures of static items first, get the technique improved, but sometimes things are just too far away to have real detail if you crop too small.
Had a closer look at the original bird and the whole thing is in a similar focus, I realise the crop above is a bit extreme to show the point but a crop of the whole bird whilst clearly ok and you can see what it is etc. still leaves me a little disappointed.
Taking on board some of the suggestions though here is a more static and less exciting object taken from a tripod and remote release 1/800 F6.3 Iso 800
and whilst the pelicans weren't as willing to participate so much in this test and seemed to prefer to fish at the other end of the beach to posing for the nut with the massive lens I did manage this one @ 1/1000 f10 iso 200 AI servo and I does show improvement.
and these little guys are a bit closer and easier to track as they run around and gave much better results @ 1/1000 F11 ISO 400
So I guess overall I haven't wasted my money on a dud lens, but just need to up my game on the technique front. Thanks for the help guys.
Taking on board some of the suggestions though here is a more static and less exciting object taken from a tripod and remote release 1/800 F6.3 Iso 800
and whilst the pelicans weren't as willing to participate so much in this test and seemed to prefer to fish at the other end of the beach to posing for the nut with the massive lens I did manage this one @ 1/1000 f10 iso 200 AI servo and I does show improvement.
and these little guys are a bit closer and easier to track as they run around and gave much better results @ 1/1000 F11 ISO 400
So I guess overall I haven't wasted my money on a dud lens, but just need to up my game on the technique front. Thanks for the help guys.
Simpo Two said:
And you have to ask yourself if you really need to zoom in that much. Digital makes it easy to go in more and more until something isn't perfect.
No probably not, but the original photo didn't satisfy with a sensible crop of just the bird, ok you could tell what it was and see the features but just left me still a little dissatisfied, The extreme crops here are more to show the detail or lack there of. Are you shooting RAW?
If not I think I would do some comparisons between RAW and JPG with post processing applied. The problem with birds if that to look really good at crop level you often need something that can extract some very fine detail and it doesn't take much movement or slight mis-focus or non-advantageous light conditions to lose that level of precision. Add in movement and a camera/lens combo probably working at or near the limits of AF operation against a target that may not always give a good contrast at the point you want in focus and, well, it's easy for things to be a tad off.
If not I think I would do some comparisons between RAW and JPG with post processing applied. The problem with birds if that to look really good at crop level you often need something that can extract some very fine detail and it doesn't take much movement or slight mis-focus or non-advantageous light conditions to lose that level of precision. Add in movement and a camera/lens combo probably working at or near the limits of AF operation against a target that may not always give a good contrast at the point you want in focus and, well, it's easy for things to be a tad off.
I was in the disappointed camp too Dave. I've got a Sony 70-400mm and until just recently was ready to send it back!
I'm getting better by practice. So that means I'm giving up, for now, trying to see into the soles of flying Blue Tits and I'm pulling back from the subject and the results are improving greatly. Also light conditions play a big part as well as getting the focus bang on. I would also suggest that the folk displaying incredible long lens photos are discarding loads whilst us new to the lens are studying every image.
Keep at it.
I'm getting better by practice. So that means I'm giving up, for now, trying to see into the soles of flying Blue Tits and I'm pulling back from the subject and the results are improving greatly. Also light conditions play a big part as well as getting the focus bang on. I would also suggest that the folk displaying incredible long lens photos are discarding loads whilst us new to the lens are studying every image.
Keep at it.
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