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Help trouble-shoot poor sharpness (3 images)
I returned recently from a trip to Tanzania. I was pleased with my photographs in general, but disappointed with the sharpness of the ones I took with a Sigma 70-300mm 1:4-5.6 APO DG lens. (The body is a Pentax *ist DS.) It's the telephoto end that is problematic..

I would like your suggestions of what I might be doing wrong, whether I am simply expecting too much from the equipment (or indeed what is realistically possible without a tripod), or even if you think something might be faulty..

All of the images below were taken hand-held, auto-focus, and represent the better shots. They are all 1:1 crops from near the centre of the frame. They were converted from RAW in Bibble without any post-processing - e.g. no noise reduction or sharpening. They are saved as JPEGs at 85% quality, which to my eye looks the same as the original..

1. 300mm, f5.6, 1/500 sec.

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2. 300mm, f5.6, 1/350 sec.

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3. 300mm, f5.6, 1/500 sec.

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4. 300mm, f5.6, 1/750 sec.

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Comments (30)

You know the rule of thumb, don't shoot at more than 1/focal length ? It was made for 35mm, and you need to convert the focal lenghts taking into account whatever crop factor your camera has .....

Comment #1

I think you are up against the limitations of a relatively cheap lens. I have read many times on this form that the Sigma 70-300 is soft at the long end, especially at maximum aperture. Also (despite the APO designation) there is a little chromatic aberration in the form of faint purple fringing on the zebra's stripes. At 1/500 sec some camera shake is possible considering that the effective focal length is 35mm terms is 450 mm. It looks to me however that the problem is just the 'softness' of this cheap lens at it's worst-performing point (300mm, f/5.6)..

This review might be of interest:.

Http://www.photozone.de/8Reviews/lenses/sigma_70300_456/index.htm.

There have been several threads debating the merits of this lens vs. the similarly-priced Tamron 70-300, which many people say is sharper at the long end. It should be possible to find these threads using the 'search' facility..

Best wishesMike..

Comment #2

Why are you checking the sharpness at a 100% crops? enlearge the image to what you need and print it at a 8x10 then look at the image and see if it objectionable. if you blow up any image enough it is going to be unsharp; it is also unrealistic. also sharpen the image to what is your normal procedure, then check..

What is this thing people have about blowing up images to crazy sizes then saying it is unsharp? pixelpeeping???..

Comment #3

Ian Goldby wrote:.

I returned recently from a trip to Tanzania. I was pleased with myphotographs in general, but disappointed with the sharpness of theones I took with a Sigma 70-300mm 1:4-5.6 APO DG lens. (The body is aPentax *ist DS.) It's the telephoto end that is problematic..

I would like your suggestions of what I might be doing wrong, whetherI am simply expecting too much from the equipment (or indeed what isrealistically possible without a tripod), or even if you thinksomething might be faulty..

All of the images below were taken hand-held, auto-focus, andrepresent the better shots. They are all 1:1 crops from near thecentre of the frame. They were converted from RAW in Bibble withoutany post-processing - e.g. no noise reduction or sharpening. They aresaved as JPEGs at 85% quality, which to my eye looks the same as theoriginal..

1. 300mm, f5.6, 1/500 sechttp://ian.goldby.net/dpreview/crop1.jpg.

2. 300mm, f5.6, 1/350 sechttp://ian.goldby.net/dpreview/crop2.jpg.

3. 300mm, f5.6, 1/500 sechttp://ian.goldby.net/dpreview/crop3.jpg.

4. 300mm, f5.6, 1/750 sechttp://ian.goldby.net/dpreview/crop4.jpg.

Well, on shot #2, you are definitely getting motion blur due to camera shake. For #1 & #3, you are borderline on the shutter speed for hand holding. So if you are not steady, that is a likely reason. The other possibility is that there was a mis-focus. Since I haven't seen the entire photo, it is hard to tell which. While the Sigma is soft wide open (especially at the long end), these shots show more than just softness that is typical for this lens..

For shot #4, well, it looks like typical softness for this lens. Please note that you are a little back focused, and the ears and horns are sharper than the eyes...

Comment #4

Hi Ian,.

Actually, it appears as others have said that there is a mix of out of focus and motion blur. The out of focus is probably not either the lens or camera but the combination. The motion blur could be caused by either camera movement or subject movement, but since you have it in so many images probably camera movement..

After checking the last image I find it out of focus by about seven pixels which is about five pixels too many for a sharp image. You will need to experiment by placing your camera on a tripod and shooting targets such as printed material. A newspaper usually works well if you can do it out of the wind. Once you determine if you have an issue with the 70-300 and your camera you can proceed from there to remedy the situation..

But obviously this doesn't help with all the photos you have taken and that's the real issue at hand. There is a solution for improving most of them to the point where you probably won't notice the out of focus or motion blur in a print. It's a software solution called "deconvolution". The least expensive way is to purchase an inexpensive software such as "Focus Magic". Focus Magic allows you to correct for both out of focus and motion blur and helps you determine which one to correct for. It's not perfect - far from it, but it will salvage many otherwise lost images.



Http://www.focusmagic.com/.

I took the liberty of applying it to your last crop below:.

Best regards,.

Lin.

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Comment #5

I wonder if you lens is at fault here I have the Sigma 70-300 APO macro (non DG) and I get much sharper pictures..

Some of your shutter speeds are definitely to slow and depending on you all of them maybe to slow. I know when I first got my lens I had trouble getting a sharp picture at 1/800th at 300mm because I was so used to a P&S I had no idea how to steady myself. With practice I can now hand hold at 1/x the focal length and occasionally get away with a about 1/3-2/3 a stop less so say 1/400th or 1/320 instead of 1/500th that I need at the 300mm range, now half the time when I try those slow shutter speeds I am leaning up against something to steady myself and even then I need to take a number of shots to make sure I get a keeper..

I have attached some 100% samples straight from my camera no PP exif is embeded..

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One thing that would be helpfull is if you could resize the original photo and post a full view. It may be an issue with your focus point and the crops you have show being out of the DOF while something else in frame is sharp in the DOF..

Hope this helps..

Mr. Fixitx..

Comment #6

I'm very grateful for the replies so far - and I'm impressed by Mr Fixit's photos, which demonstrate that the lens should be capable of much more than I have achieved with it. I find that encouraging..

Camera shake: Well, looking at the crop of the zebra's eye, it does look like the blurring is all in the same direction. However, there is much less, or no, obvious directionality to the blurring in the other photos, at least to my eye. Should I expect this?.

I took the photos from a safari vehicle. The engine was off and my elbow was braced against the roof hatch, with that arm's hand supporting the lens at the very front. That gave me a problem with the front element rotating when the camera focussed, but I rested the lens hood on a V between my thumb and index finger so that it was free to rotate. Is there a better way? Generally I reckon I have a fairly steady hand. At 17mm I can comfortably hand-hold at 1/30 sec, and get acceptable results (much sharper than the samples here) at 1/15 sec..

As far as focus is concerned, looking again at the full images, the detail a little behind the area I was intending to focus seems to be sharper. Does this mean that the lens is badly calibrated? Is there anything I can do about this? I will try making some test shots using a tripod during the week to see if this is a systematic error..

Are there any generally useful techniques for getting the best results from the camera's autofocus? I know about making sure that the camera chooses the correct focusing point - the *istDS shows a red light over the point it is using for focus. Is there anything else I should know about?.

I've uploaded the full-frame images: here they are:http://ian.goldby.net/dpreview/full1.jpg (1.9MB)http://ian.goldby.net/dpreview/full2.jpg (2.2MB)http://ian.goldby.net/dpreview/full3.jpg (2.7MB)http://ian.goldby.net/dpreview/full4.jpg (1.8MB).

I thought that would be better than resizing them to fit since virtually anything will look acceptably sharp at 480px width!.

Lin - I appreciate your help on improving the images. I have to say though that at least at the 1:1 size the 'cure' looks to me worse than the original image. Maybe that's a matter of personal taste though. I'm sure my photos could benefit from a little post-processing. The trouble is, I find that the sharpening filter in Bibble only seems to work on photos that are already reasonably sharp. Can anyone suggest settings that I should be trying?..

Comment #7

You're doing some over-thinking here..

As a general rules, telephoto zoom lenses are at their worst at maximum zoom. They're at their worst wide open. Your pcitures qualify for both these problems..

And there's no getting around shutter speeds. Bracing is bettr than nothing, but does not solve all problems..

So, you comb ined three problems..

All that said, do you have nice looking 4x6 and 5x7 prints to remember your trip?.

And next time, try to get one more aperture, one more shutter speed, and pull the zoom back to about 250mm..

BAK..

Comment #8

Ian Goldby wrote:.

I'm very grateful for the replies so far - and I'm impressed by MrFixit's photos, which demonstrate that the lens should be capable ofmuch more than I have achieved with it. I find that encouraging..

Camera shake: Well, looking at the crop of the zebra's eye, it doeslook like the blurring is all in the same direction. However, thereis much less, or no, obvious directionality to the blurring in the.

The acid test is really the print, not the appearance on screen. The convolution correction and contrast border enhancement looks bad on screen, but remember you are looking at what a huge print - much larger than you would want to print this - would look like. Try printing the original and the deconvoluted print and I think you will see how it helps..

Obviously there is no way to move seven pixels without inducing some artifacts which is what this has done, but these artifacts "shouldn't" be visible in a print, but the increase in true sharpness (as opposed to only edge boundary contrast differentiation) "should"..

Best regards,.

Lin.

Other photos, at least to my eye. Should I expect this?.

I took the photos from a safari vehicle. The engine was off and myelbow was braced against the roof hatch, with that arm's handsupporting the lens at the very front. That gave me a problem withthe front element rotating when the camera focussed, but I rested thelens hood on a V between my thumb and index finger so that it wasfree to rotate. Is there a better way? Generally I reckon I have afairly steady hand. At 17mm I can comfortably hand-hold at 1/30 sec,and get acceptable results (much sharper than the samples here) at1/15 sec..

As far as focus is concerned, looking again at the full images, thedetail a little behind the area I was intending to focus seems to besharper. Does this mean that the lens is badly calibrated? Is thereanything I can do about this? I will try making some test shots usinga tripod during the week to see if this is a systematic error..

Are there any generally useful techniques for getting the bestresults from the camera's autofocus? I know about making sure thatthe camera chooses the correct focusing point - the *istDS shows ared light over the point it is using for focus. Is there anythingelse I should know about?.

I've uploaded the full-frame images: here they are:http://ian.goldby.net/dpreview/full1.jpg (1.9MB)http://ian.goldby.net/dpreview/full2.jpg (2.2MB)http://ian.goldby.net/dpreview/full3.jpg (2.7MB)http://ian.goldby.net/dpreview/full4.jpg (1.8MB)I thought that would be better than resizing them to fit sincevirtually anything will look acceptably sharp at 480px width!.

Lin - I appreciate your help on improving the images. I have to saythough that at least at the 1:1 size the 'cure' looks to me worsethan the original image. Maybe that's a matter of personal tastethough. I'm sure my photos could benefit from a littlepost-processing. The trouble is, I find that the sharpening filter inBibble only seems to work on photos that are already reasonablysharp. Can anyone suggest settings that I should be trying?..

Comment #9

The full image. This is a three pixel shift which brings it closer to focus for screen display, but still short of what you would want for print:.

Http://www.lin-evans.net/dpreview/crop4.jpg.

Best regards,.

Lin.

Ian Goldby wrote:.

I'm very grateful for the replies so far - and I'm impressed by MrFixit's photos, which demonstrate that the lens should be capable ofmuch more than I have achieved with it. I find that encouraging..

Camera shake: Well, looking at the crop of the zebra's eye, it doeslook like the blurring is all in the same direction. However, thereis much less, or no, obvious directionality to the blurring in theother photos, at least to my eye. Should I expect this?.

I took the photos from a safari vehicle. The engine was off and myelbow was braced against the roof hatch, with that arm's handsupporting the lens at the very front. That gave me a problem withthe front element rotating when the camera focussed, but I rested thelens hood on a V between my thumb and index finger so that it wasfree to rotate. Is there a better way? Generally I reckon I have afairly steady hand. At 17mm I can comfortably hand-hold at 1/30 sec,and get acceptable results (much sharper than the samples here) at1/15 sec..

As far as focus is concerned, looking again at the full images, thedetail a little behind the area I was intending to focus seems to besharper. Does this mean that the lens is badly calibrated? Is thereanything I can do about this? I will try making some test shots usinga tripod during the week to see if this is a systematic error..

Are there any generally useful techniques for getting the bestresults from the camera's autofocus? I know about making sure thatthe camera chooses the correct focusing point - the *istDS shows ared light over the point it is using for focus. Is there anythingelse I should know about?.

I've uploaded the full-frame images: here they are:http://ian.goldby.net/dpreview/full1.jpg (1.9MB)http://ian.goldby.net/dpreview/full2.jpg (2.2MB)http://ian.goldby.net/dpreview/full3.jpg (2.7MB)http://ian.goldby.net/dpreview/full4.jpg (1.8MB)I thought that would be better than resizing them to fit sincevirtually anything will look acceptably sharp at 480px width!.

Lin - I appreciate your help on improving the images. I have to saythough that at least at the 1:1 size the 'cure' looks to me worsethan the original image. Maybe that's a matter of personal tastethough. I'm sure my photos could benefit from a littlepost-processing. The trouble is, I find that the sharpening filter inBibble only seems to work on photos that are already reasonablysharp. Can anyone suggest settings that I should be trying?..

Comment #10

Ian Goldby wrote:.

I'm very grateful for the replies so far - and I'm impressed by MrFixit's photos, which demonstrate that the lens should be capable ofmuch more than I have achieved with it. I find that encouraging..

Camera shake: Well, looking at the crop of the zebra's eye, it doeslook like the blurring is all in the same direction. However, thereis much less, or no, obvious directionality to the blurring in theother photos, at least to my eye. Should I expect this?.

I took the photos from a safari vehicle. The engine was off and myelbow was braced against the roof hatch, with that arm's handsupporting the lens at the very front. That gave me a problem withthe front element rotating when the camera focussed, but I rested thelens hood on a V between my thumb and index finger so that it wasfree to rotate. Is there a better way? Generally I reckon I have afairly steady hand. At 17mm I can comfortably hand-hold at 1/30 sec,and get acceptable results (much sharper than the samples here) at1/15 sec..

As far as focus is concerned, looking again at the full images, thedetail a little behind the area I was intending to focus seems to besharper. Does this mean that the lens is badly calibrated? Is thereanything I can do about this? I will try making some test shots usinga tripod during the week to see if this is a systematic error..

Are there any generally useful techniques for getting the bestresults from the camera's autofocus? I know about making sure thatthe camera chooses the correct focusing point - the *istDS shows ared light over the point it is using for focus. Is there anythingelse I should know about?.

I've uploaded the full-frame images: here they are:http://ian.goldby.net/dpreview/full1.jpg (1.9MB)http://ian.goldby.net/dpreview/full2.jpg (2.2MB)http://ian.goldby.net/dpreview/full3.jpg (2.7MB)http://ian.goldby.net/dpreview/full4.jpg (1.8MB)I thought that would be better than resizing them to fit sincevirtually anything will look acceptably sharp at 480px width!.

Lin - I appreciate your help on improving the images. I have to saythough that at least at the 1:1 size the 'cure' looks to me worsethan the original image. Maybe that's a matter of personal tastethough. I'm sure my photos could benefit from a littlepost-processing. The trouble is, I find that the sharpening filter inBibble only seems to work on photos that are already reasonablysharp. Can anyone suggest settings that I should be trying?.

Don't over think all this, I think you are going through what I've been learning to over come. Two things, the first is breathing and tripping the shutter release. I've found I don't need to work as hard at being a human tripod if I am exhaling as I trip the shutter. As well, I get excited when I think I am about to get a great shot (wild animals are the worst because I don't want to loose the opportunity in front of me) ... It causes me to slam down the shutter release button... Exhaling helps calm this action on my part also..

The second thing that plagued me was how I setup the auto focus and was metering my focus. Until I found settings that worked for me I thought I had a back focus problem..

...Dennis..

Comment #11

5D DjD wrote:.

The second thing that plagued me was how I setup the auto focus andwas metering my focus. Until I found settings that worked for me Ithought I had a back focus problem..

This may be exactly what I need to solve. Can you elaborate? (What does 'metering my focus' mean? What settings work for you?)..

Comment #12

Lin Evans wrote:.

The full image. This is a three pixel shift which brings it closer tofocus for screen display, but still short of what you would want forprint:.

Http://www.lin-evans.net/dpreview/crop4.jpg.

That one looks much more natural to me. But as you say, it is how they look when printed that is important..

Cheers...

Comment #13

Hi Lin.

How is it possible to determine that an image is "out-of-focus" by X pixels ? .

ThanksMike..

Comment #14

Ian Goldby wrote:.

5D DjD wrote:.

The second thing that plagued me was how I setup the auto focus andwas metering my focus. Until I found settings that worked for me Ithought I had a back focus problem..

This may be exactly what I need to solve. Can you elaborate? (Whatdoes 'metering my focus' mean? What settings work for you?).

On my KM 5D I have 3 AF selections, Currently I have been relying on Wide Area and getting good results. The other choices are Spot and Focus Area. I also have a control for Auto Focus, the choices are Single shot AF, Direct Manual, Automatic AF and Continous AF. I've been using single shot and even with a continuous burst of several shot it stays fairly well focused..

I've also been using Multi segment metering as opposed to my other choices of Center weighted and Spot..

Another thing I'm finding out is each lens I have has a sweet spot. The Tamron 28-300 I have really likes F9 so I try to stay there or just either side of it and have adjusted the ISO to keep me shooting around there with good results..

There really is a lot to all this picture taking and I grasp a little at a time so I may not be using my equipment to it's fullest. I do like to play and that is a big plus in the digital age......Dennis..

Comment #15

Let's assume that the lens isn't the best quality at 300mm. In addition to that, I see other things that tend to hurt sharpness..

1. Very contrasty scene - extreme contrast causes a bunch of problems, such as chromatic abberation and general loss of sharpness..

2. You are shooting wide open. Try stopping down. Lenses are never their sharpest wide open.

3. Distance from subject. This is especially so for the bird shot, but also applies to the first shot to a lesser extent. The bird is simply too small in the frame - to maximize sharpness you need to fill up the viewfinder as much as possible with your subject when shooting telephoto. Nowadays I don't even take shots where the subject is such a small part of the image..

4. Glare... by that I mean glare of the sun. Judging by the shadows, the sun was somewhat in front of you. It may have been high in the sky, but it was still in front of you - it doesn't take much. That will kill image quality all the time. Had you turned around 180 degrees and fired some shots you would have seen better image quality..

Comment #16

Ian Goldby wrote:.

I returned recently from a trip to Tanzania. I was pleased with myphotographs in general, but disappointed with the sharpness of theones I took with a Sigma 70-300mm 1:4-5.6 APO DG lens. (The body is aPentax *ist DS.) It's the telephoto end that is problematic..

All of the images below were taken hand-held,.

You were trying to get sharp pics with a handheld lens at 300mm?...Thats virtually impossible!.

You should have used a camera support such as a monopod, a tripod, the side of your 4x4 (if you were in one?) or even a handy tree branch to eliminate motion blur..

DSG.

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Http://sigmasd10.fotopic.net/..

Comment #17

DaSigmaGuy wrote:.

Ian Goldby wrote:.

I returned recently from a trip to Tanzania. I was pleased with myphotographs in general, but disappointed with the sharpness of theones I took with a Sigma 70-300mm 1:4-5.6 APO DG lens. (The body is aPentax *ist DS.) It's the telephoto end that is problematic..

All of the images below were taken hand-held,.

You were trying to get sharp pics with a handheld lens at300mm?...Thats virtually impossible!You should have used a camera support such as a monopod, a tripod,the side of your 4x4 (if you were in one?) or even a handy treebranch to eliminate motion blur..

DSG.

Image control:Zoom outZoom 100%Zoom inExpand AllOpen in new window.

Http://sigmasd10.fotopic.net/.

Take a trip through the forums here, there are guys hand holding 500mm with great results....Dennis..

Comment #18

You are handholding a 300mm lens on a 1.5crop dslr that is 450mm. no way. you can of course make 4x6 prints of the images, but hey simply are not sharp enough for enlarging..

I think for the kind if trip you took to africa you would want enlarged mountable shots. for that you need what is called critical sharpness. this means that the image is sharp enough to be able to withstand enlargeing to any extent necessary to acheive the blowup required. all this without ANY excuses as to final result..

When you are talking that kind of sharpness you need every kind of break you can think of and use. and handholding does not cut it..

You should be talking tripod, monopod, beanbag on vechicle roof, or the taut rope that you stand on trick(go to hardware store buy eye that screws into tripod mount 1/4inchX20thread get 6ft nylon rope tie to eye put other end under one foot pull taut sharpness improved..

Also do not brace against the vechicle if engine is still running the vibration will come through. ask driver to turn engine off..

Remember that a 500mm lens has to have 10 times the steadyness of a 50mm just to get the same result. if you thinking of sr/vr/is do not a 500mm lens is really 750mm on a pentan or nikon dslr. that means that you have to shoot at 1/750 minus 2 stops. or about 1/190. that is just to get back to where the 50mm is shot at. at that point you do not have critical sharpness for enlargements.

If you look at m reichman's web site he states and does take almost all his really good shots on a tripod...

Comment #19

5D DjD wrote:.

DaSigmaGuy wrote:.

Ian Goldby wrote:.

I returned recently from a trip to Tanzania. I was pleased with myphotographs in general, but disappointed with the sharpness of theones I took with a Sigma 70-300mm 1:4-5.6 APO DG lens. (The body is aPentax *ist DS.) It's the telephoto end that is problematic..

All of the images below were taken hand-held,.

You were trying to get sharp pics with a handheld lens at300mm?...Thats virtually impossible!You should have used a camera support such as a monopod, a tripod,the side of your 4x4 (if you were in one?) or even a handy treebranch to eliminate motion blur..

DSG.

Image control:Zoom outZoom 100%Zoom inExpand AllOpen in new window.

Http://sigmasd10.fotopic.net/.

Take a trip through the forums here, there are guys hand holding500mm with great results..

But only because those lenses have IS/VR or the camera does..

There is currently only one Sigma lens that has IS (The 80-400mm EX OS) and he was'nt using one of those and his camera does'nt have IS either so in this case it would have been essential for him to use a camera support of some kind..

DSG.

Image control:Zoom outZoom 100%Zoom inExpand AllOpen in new window.

Http://sigmasd10.fotopic.net/..

Comment #20

DaSigmaGuy wrote:.

You were trying to get sharp pics with a handheld lens at300mm?...Thats virtually impossible!.

Hand held shots at 300mm are not impossible. You just need a fast enough shutterspeed. Here are handheld zoo shots at 400mm on a 1.6x crop camera..

These are 100% crops, no PP, JPEG straight from the camera..

Canon XT, 400mm, f5.6, 1/800, ISO400 (Av mode).

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Here are the same full resized photos:.

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Comment #21

Those are awesome shots. If I could get close to that sharpness I'd be happy...

Comment #22

Hi folks. Thanks again for the advice offered. I thought it would be a good idea for me to post this follow-up. I've just done some tests with the lens to see whether there is anything wrong with the lens itself (Sigma 70-300 f4-5.6 APO DG), and how I get best sharpness with it..

All of the tests were done with the camera mounted on a tripod and with the mirror locked up, to minimise camera shake. Of course this alone makes the tests totally unrepresentative of real-world conditions for me, since in situations where I would be using this lens I would never be able to use a tripod....

Anyway, here are the results. (As always, no noise reduction or sharpening):.

1. 300mm, f5.6 ISO800 1/45sec.

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2. 300mm, f8.0 ISO800 1/30sec.

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3. 300mm, f16.0 ISO800 1/6sec.

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4. 200mm, f5.6 ISO800 1/45sec.

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5. 200mm, f8.0 ISO800 1/30sec.

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What I conclude from this is the following:.

1. Sharpness at f5.6 is quite poor. Stopping down to f8.0 improves it considerably, and stopping down further to f16.0 gives a further small improvement..

2. The lens is no sharper at 200mm. So limiting myself to 200mm and cropping the final picture will result in *worse* sharpness than taking the picture at 300mm..

3. The gross unsharpness in the pictures I originally posted is not present in these test shots, so I can be pretty confident that it was operator error (camera shake and poor focusing) not a fault with the lens..

Finally, here is a shot of a ruler taken at an oblique angle to test the focusing..

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The autofocus spot was aligned with the 150 mark, so actually the lens/camera combination is focusing slightly in front of the target. I repeated this result several times, so any systematic error is in the opposite direction to the problems in the pictures I originally posted..

Final conclusions:.

1. It's OK to use the full zoom range of the lens..

2. Stick to shutter speeds of 1/1000 sec and faster, and apertures of f8.0 and smaller..

It's this last conclusion that is going to be a problem of course. Looks like I'm going to use higher ISO speeds and accept the increase in sensor noise..

Well, this has been useful. Thanks everyone...

Comment #23

This has been an interesting thread. Your conclusions agree exactly with the conclusions I came to a while ago when I was disappointed with some of the first shots from my Pentax DA 50-200 and did similar tests: (i) I don't use it wide open unless it's essential (better to increase the ISO one stop); and (ii) it's a lot easier to get camera shake than I had reaslised, even at quite high shutter speeds. Hardly revolutionary of course but working it out for oneself gives it more impact than just reading it in a book!.

Best wishesMike..

Comment #24

Mike & all, I'm just following along with interest...just wanted to say that I agree about keeping your shutterspeeds high as possible, but I'm concerned that you guys are going to blame being "wide open" for the lack of sharpness. The difference between 5.6 and f8 in the pics posted is dramatic to my eyes, too much so. Is something wrong with the lens? F5.6 is already stopped down a little isn't it? It's a shame that the lens doesn't perform better wide-open, because it's a joy to shoot with low apertures I think..

Http://www.flickr.com/photos/jcovert..

Comment #25

Jizzer wrote:.

Mike & all, I'm just following along with interest...just wanted tosay that I agree about keeping your shutterspeeds high as possible,but I'm concerned that you guys are going to blame being "wide open"for the lack of sharpness. The difference between 5.6 and f8 in thepics posted is dramatic to my eyes, too much so. Is something wrongwith the lens? F5.6 is already stopped down a little isn't it? It's ashame that the lens doesn't perform better wide-open, because it's ajoy to shoot with low apertures I think..

At 300mm, f5.6 is wide open for that lens. Nothing wrong with the lens, that's just they way it is with a consumer lens. The sweet spot will be around f8 for lenses. The more expensive (professional type) lenses will not only be faster, but allow shooting wide open without much loss of sharpness and contrast...

Comment #26

Jizzer wrote:.

The difference between 5.6 and f8 in the pics posted is dramaticto my eyes, too much so. Is something wrong with the lens?.

I agree that the sharpness difference between f5.6 and f8.0 is more than I would have expected for just one stop, but that is nothing compared to the difference it seems it will make if I can avoid camera shake and focus accurately. In fact it may be that when constrained by light it is still better to shoot wide-open at a higher shutter speed than to shoot stopped down to the lens' optimum aperture and risk camera shake. Ideally there would always be enough light to get a good exposure at 1/1000 sec f8.0, but how often do we really get such bright conditions?.

Also, don't forget that these test shots were with a tripod and the mirror locked up, so in that sense they are not representative of real-world conditions...

Comment #27

DaSigmaGuy wrote:.

You were trying to get sharp pics with a handheld lens at300mm?...Thats virtually impossible!.

Wanna bet? .

You should have used a camera support such as a monopod, a tripod,the side of your 4x4 (if you were in one?) or even a handy treebranch to eliminate motion blur..

Take a trip through the forums here, there are guys hand holding500mm with great results..

But only because those lenses have IS/VR or the camera does.There is currently only one Sigma lens that has IS (The 80-400mm EXOS) and he was'nt using one of those and his camera does'nt have ISeither so in this case it would have been essential for him to use acamera support of some kind..

Nope, because the guys use good handhelding technique and fast shutter speeds..

To my eye, those images don't look blurry due to camera shake, but to the lens OR focus error...

Comment #28

How is it the 300mm and 200mm shots came out the same size?...Dennis..

Comment #29

5D DjD wrote:.

How is it the 300mm and 200mm shots came out the same size?.

I moved the camera closer..

In the real world I would have had to blow the image up x1.5, but here I was just trying to do a 'best case' comparison...

Comment #30

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This question was taken from a support group/message board and re-posted here so others can learn from it.

 

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