New lens issues
Discussion
Hi
Novice question.
I've only had a DSLR for a couple of years so still very much learning. I got a used Sigma 120-400 before Christmas and I've only used a few times. I took some photos with but I can't seem to get it to focus on the subject. I've set my 70D to P mode so that I can keep the flash off and choose my focus preference - which I set to single point. I took this shot but I don't think any part of it is in focus. I aimed the focus point on the grebe's back - it was at 400mm zoom.
My camera chose F6.3, 1/500 and an ISO of 2500 - this seems high to me. It was on Sunday so the weather was slightly overcast but bright enough (in my view). I would be interested in any feedback as to why the photo looks so out of focus. The lens is the OS version so it has stabilisation - and I was hand-holding. At the time, (leaning against a tree) I thought I'd held the camera very still but maybe . . .
Most of the other pictures I took have similar issues so I'd love to know why.
I've resized the picture to get it onto this site but it was around 7MB.
Thanks.
Novice question.
I've only had a DSLR for a couple of years so still very much learning. I got a used Sigma 120-400 before Christmas and I've only used a few times. I took some photos with but I can't seem to get it to focus on the subject. I've set my 70D to P mode so that I can keep the flash off and choose my focus preference - which I set to single point. I took this shot but I don't think any part of it is in focus. I aimed the focus point on the grebe's back - it was at 400mm zoom.
My camera chose F6.3, 1/500 and an ISO of 2500 - this seems high to me. It was on Sunday so the weather was slightly overcast but bright enough (in my view). I would be interested in any feedback as to why the photo looks so out of focus. The lens is the OS version so it has stabilisation - and I was hand-holding. At the time, (leaning against a tree) I thought I'd held the camera very still but maybe . . .
Most of the other pictures I took have similar issues so I'd love to know why.
I've resized the picture to get it onto this site but it was around 7MB.
Thanks.
It doesn't seem great I agree. I can't see any technique issues and there's nothing else that seems sharper, which would indicate AF inaccuracy (though it's hard to assess the area just in front as it's all water/ripples)
I wonder whether at ISO 2500 the camera is 'smearing' the pixels in an attempt to reduce noise? Other ideas are (1) not a great lens (2) shoot RAW and control sharpening yourself.
Take more photos under more controlled conditions to see what the weak link is.
I wonder whether at ISO 2500 the camera is 'smearing' the pixels in an attempt to reduce noise? Other ideas are (1) not a great lens (2) shoot RAW and control sharpening yourself.
Take more photos under more controlled conditions to see what the weak link is.
Thanks for the replies. The lens does have a filter. I bought the lens second-hand and the bloke left his filter on for me. I would never have thought that would cause a problem - but your experience has made me think again! I'll see what difference taking it off makes. I do agree that it's early days and I need to do some more testing to try and find the cause - if there is one. Using the lens at various zoom levels is a good shout.
I was worried that maybe using P was not the right option. I could use shutter priority and put it on 1/400 or 1/500 manually but I don't suppose the aperture or ISO would change significantly to the P mode settings anyway.
I was worried that maybe using P was not the right option. I could use shutter priority and put it on 1/400 or 1/500 manually but I don't suppose the aperture or ISO would change significantly to the P mode settings anyway.
maccboy said:
I don't suppose the aperture or ISO would change significantly to the P mode settings anyway.
Definitely lose the filter.Exposure per se is not the issue here and your shutter speed is fast enough to avoid camera shake.
If you do take up RAW you can fix white balance too - it looks very blue to me.
With a bit more experience of all the variables and what they do, you'll be able to analyse your photos and work out how to fix them quite quickly.
Am new to all this DSLR stuff having just purchased a 700D and have been experimenting with ISO, aperture and shutter speeds, and have found that high ISO tends to make the image much more grainy, also, if you set a lower f number the lens will let in more light in, so the shutter speed can increase, which will reduce the chance of blur at the expense of depth of field, though I doubt very much you would need to worry about that when photographing a duck at some distance unless you are using a very very expensive zoom lens.
The ISO at 2500 seems a bit high considering it's not dark, I would try setting the ISO upper limit to 400 or 800. Also the shutter speed seems rather high for shooting such a slow moving object. Have you tried using shutter priority and bringing the speed down to 150th or less?
What is the total spec for the zoom lens including the aperture, because from what I can gather, many lenses have a sweet spot, if yours is the Sigma 120-400 4.5-5.6 then perhaps try it at f8 when the zoom is set at 400mm to see if it improves the sharpness, if you post the specs on here I'm sure someone will be able to guide you.
Incidentally, did you take any more photographs of the duck because it's not unknown for some photos to be out of focus for reasons only known to the camera!
I found a review of the Sigma 120-400 4.5-5.6 which might be of interest to you: https://darwinwiggett.wordpress.com/2010/02/23/len...
The ISO at 2500 seems a bit high considering it's not dark, I would try setting the ISO upper limit to 400 or 800. Also the shutter speed seems rather high for shooting such a slow moving object. Have you tried using shutter priority and bringing the speed down to 150th or less?
What is the total spec for the zoom lens including the aperture, because from what I can gather, many lenses have a sweet spot, if yours is the Sigma 120-400 4.5-5.6 then perhaps try it at f8 when the zoom is set at 400mm to see if it improves the sharpness, if you post the specs on here I'm sure someone will be able to guide you.
Incidentally, did you take any more photographs of the duck because it's not unknown for some photos to be out of focus for reasons only known to the camera!
I found a review of the Sigma 120-400 4.5-5.6 which might be of interest to you: https://darwinwiggett.wordpress.com/2010/02/23/len...
It is the 4.5-5.6 lens. Regarding shutter speed, I was told that to avoid shake, if handheld, you should use a slowest speed of your lens length. So 1/400 for a 400mm. I don't know if that's a good guide in all scenarios but it's what I try to use.
I did take quite a few photos of the grebe and other birds but wasn't really knocked out with the focus on any of them!
I did take quite a few photos of the grebe and other birds but wasn't really knocked out with the focus on any of them!
maccboy said:
It is the 4.5-5.6 lens. Regarding shutter speed, I was told that to avoid shake, if handheld, you should use a slowest speed of your lens length. So 1/400 for a 400mm. I don't know if that's a good guide in all scenarios but it's what I try to use.
I did take quite a few photos of the grebe and other birds but wasn't really knocked out with the focus on any of them!
For that rule of thumb you need to consider the crop factor of the sensor too. The 70D has an APS-C sized sensor so you need to multiply the focal length of your lens by 1.6 to get the slowest shutter speed recommended for handholding.I did take quite a few photos of the grebe and other birds but wasn't really knocked out with the focus on any of them!
Having said all of that, you have a stabilised lens so you can probably safely drop that by at least a couple of stops and still be OK on stationary or slow moving objects.
I would definitely lose the filter, get into RAW mode and see what you can see after more testing.
I own that lens and have shot many thousands of images with it...
At f/6.3 and 400mm, thats pretty much what you would expect. The lens is not the sharpest, combined with an average AF means many shots look similar to that. Some a little sharper, some not.
I try never to use the lens with an aperture wider then f/8.0 Its a good bit sharper from there onward.
Its is a capable enough lens...
IMG_1324 by jimmyb156, on Flickr
But it certainly has its limitations.
At f/6.3 and 400mm, thats pretty much what you would expect. The lens is not the sharpest, combined with an average AF means many shots look similar to that. Some a little sharper, some not.
I try never to use the lens with an aperture wider then f/8.0 Its a good bit sharper from there onward.
Its is a capable enough lens...
IMG_1324 by jimmyb156, on FlickrBut it certainly has its limitations.
Edited by jimmy156 on Tuesday 12th January 19:51
jimmy156 said:
I own that lens and have shot many thousands of images with it...
At f/6.3 and 400mm, thats pretty much what you would expect. The lens is not the sharpest, combined with an average AF means many shots look similar to that. Some a little sharper, some not.
I try never to use the lens with an aperture wider then f/8.0 Its a good bit sharper from there onward.
Its is a capable enough lens...
IMG_1324 by jimmyb156, on Flickr
But it certainly has its limitations.
You say the lens might have a few limitations, but have just taken a quick look at some of your pics on Flickr and quite a few of them are quite outstanding, I think I need to try out the 55-250mm lens I have lurking around somewhere At f/6.3 and 400mm, thats pretty much what you would expect. The lens is not the sharpest, combined with an average AF means many shots look similar to that. Some a little sharper, some not.
I try never to use the lens with an aperture wider then f/8.0 Its a good bit sharper from there onward.
Its is a capable enough lens...
IMG_1324 by jimmyb156, on FlickrBut it certainly has its limitations.
Edited by jimmy156 on Tuesday 12th January 19:51
Ahh, grebes.
A favourite subject of mine. Bloody hard work though. For a start their plumage has the same frequency as the water they live in, although the colours are slightly different. Then they have this white plumage which blows to white easily, so you need to expose for the white and bring the darker colours up in the RAW file, which again hurts the colour and noise in the dark areas. They also have lovely gem like red eyes with an orange center that glow when the light is right. You will find it is very hard to take a good picture without filling the frame and then downsampling. Rewarding when you get it right though.
I would - watch them for a while, and figure out if there is a good place where they fish and with the sun behind me, put that sigma on a tripod, hunker down so I don't appear threatening and wait for the grebe to come close to me. I would also focus on the eye and let the body go a little out of focus. This time of year look out for the Male to make a start on his mating display, he will flare his neck feathers and put his wings in a distinctive V shape.
A few of mine with a Nikon 500mm F4 P lens.
Grebe_Babies_Riding_3 by Nature Ist, on Flickr
Grebe_Portrait by Nature Ist, on Flickr
Grebe_Fishing by Nature Ist, on Flickr
A favourite subject of mine. Bloody hard work though. For a start their plumage has the same frequency as the water they live in, although the colours are slightly different. Then they have this white plumage which blows to white easily, so you need to expose for the white and bring the darker colours up in the RAW file, which again hurts the colour and noise in the dark areas. They also have lovely gem like red eyes with an orange center that glow when the light is right. You will find it is very hard to take a good picture without filling the frame and then downsampling. Rewarding when you get it right though.
I would - watch them for a while, and figure out if there is a good place where they fish and with the sun behind me, put that sigma on a tripod, hunker down so I don't appear threatening and wait for the grebe to come close to me. I would also focus on the eye and let the body go a little out of focus. This time of year look out for the Male to make a start on his mating display, he will flare his neck feathers and put his wings in a distinctive V shape.
A few of mine with a Nikon 500mm F4 P lens.
Grebe_Babies_Riding_3 by Nature Ist, on FlickrGrebe_Portrait by Nature Ist, on FlickrGrebe_Fishing by Nature Ist, on FlickrGassing Station | Photography & Video | Top of Page | What's New | My Stuff