Looking for some advice and possibly some tips regarding zoom lens and focusing at distance. As usual nothing is ever straightforward. I was kindly given a damaged lens(Sigma 170-500mm 1:5-6.3APO DG) with the instructions ‘if you can fix it you can keep it’. The lens mount was hanging off the lens and the internal switch to change from manual to auto focus was, and still is broken. I managed to set the switch to auto focus and secure the lens mount back on. The lens now works fine but on auto focus only. I have had great results when shooting garden birds at relatively short distances (where auto focus is advantageous due to the rapid movements of the small birds), but cannot seem to get sharp pictures when trying for more distant subjects. Even on bright days with high shutter speeds and using self-timer, I am getting good exposures but always lacking sharpness. I realise that this lens is more at the budget end of the market for such things and was not expecting spectacular results, but was hoping for decent images at distances of 100m or so. Has anyone had similar problems like this and would any of the following make any great difference?
Camera used is a Canon EOS500D.
I would very much appreciate any tips or advice anyone might have regarding this.
Many thanks in advance
Paul
My bird photos HERE
Thanks Alan. Didn't realise I would lose autofocus with converter.
What aperture are you using the lens at? The 170-500 is probably not going to give you brilliant results wide open at the longest focal length: try stopping it down a bit and see what it's like. You may also need some help from a solid tripod. You might try some specific experiments to see if it's ok - f/8 or f/11 maybe, a shutter speed of at least 1/1000 sec, a static subject and try a few shots. If they still look bad, try dropping the focal length to 400mm and see what that looks like.
it's possible of course that the lens has some misaligned elements that are causing the problem - it certainly sounds like it was bounced! I wouldn't bother with a teleconverter - it'll likely make a bad pic worse I'm afraid. Some camera bodies have AF micro adjust that may be an answer too, but I don't think the 500 does....
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There are tricks like taping the pins on Canon converters, but they're hit and miss at best. AF needs light and not enough means AF can struggle. It's partly the reason the Sigma lenses aren't always brilliant at the long end - f/6.3 is smaller then the minimum Canon like for reliable AF (the lens fibs somewhat to get it to AF at all!).
If you do the test Bob mentions, you may be able to spot if the lens is front or back focussing (ie the subject is out of focus but the fore or background is sharp). If nothing looks sharp, either you're shaking or the lens is just naff at full stretch :-)
Many thanks guys. You've given me a lot to think about. Checked the data on my photos and yes, the aperture is almost always very wide. You're correct that the 500 doesn't have AF micro adjust. I do use a tripod but admit that it isn't the heaviest one around. There isn't an image stabilisation switch on the lens to switch off and I don't think the body has it built in? There are no marks on the body of the lens and I suspect the camera body was being held, the weight of the lens causing them to part company. Will certainly follow your advice and carry out a series of test shots (and hang a weight from my tripod) to try to work out what's going on. Once again many thanks. Sound advice that is very much appreciated.
Can you post a picture with the Exif still attached, Paul!
Jim
My Pictures
My Fbook Group
I agree Bob. Was talking to a chap at Vane Farm Loch Leven on Sunday who was armed with a high end Canon 500mm + 1x4 converter. Asked him about about his set up and he told me that it's never enough. If in the end I get decent photo's of my garden birds with this lens I'll consider myself fortunate a be very happy indeed. Once again many thanks for advice. Will post how it goes once tests have been done.
Hi James. Apologies, but not sure what 'Exif still attached' means.
EXIF stands for ‘Exchangeable Image File’ data and it is the information that your camera stores with you image file that tells you about it.
This is the Exif from one of my pictures.File Name IMG_9609.CR2Camera Model Canon EOS 7DFirmware Firmware Version 2.0.3Shooting Date/Time 10/10/2013 13:35:24Author **********Copyright Notice **************Owner's Name Shooting Mode Aperture-Priority AETv(Shutter Speed) 1/2000Av(Aperture Value) 5.6Metering Mode Spot MeteringAE lock ONExposure Compensation -1/3ISO Speed 400Auto ISO Speed OFFLens EF400mm f/5.6L USMFocal Length 400.0mmImage Size 5184x3456Image Quality RAWFlash OffFE lock OFFWhite Balance Mode AutoAF Mode AI Servo AFTracking sensitivity 1AF area select mode AF Point expansionPicture Style NeutralSharpness 0Contrast 1Saturation 1Color tone 0Color Space sRGBLong exposure noise reduction 0:OffHigh ISO speed noise reduction 3:DisableHighlight tone priority 0:DisableAuto Lighting Optimizer DisablePeripheral illumination correction EnableDust Delete Data NoFile Size 28123KBDrive Mode High-speed continuous shootingLive View Shooting OFFSatellite signal status Date/Time(UTC) Latitude Longitude Altitude Geographic coordinate system Camera Body No. 2481221880Comment
Hi folks. Can't thank everyone enough for help and advice on this and all other things since joining this community. I'm of the opinion that without the top notch expensive gear we would all be deprived of spectacular detailed images of the world around us and be very much the worse off for it. On the other hand I'd much rather see 'far from perfect' images than no images at all. After all, watching the birds without any optical aid at all is how we all fell in love with them in the first place.!!
An update on my progress in trying out the suggestions and help given to me on this thread.
The first thing I did was to attach a weight to my tripod to help stabilise it. I then got permission from Mrs A to use her favourite doorstop as a test subject and set it up at bottom of the garden approximately 25 yards away. I set up the camera and took a series of shots using a 10 second self timer. With the lens at 500mm I set the camera to aperture priority and took shots from f/6.3 to f/16 allowing the camera to calculate ISO and shutter speed. It was very dull and showery here today so the camera set ISO at 1600 and shutter speeds from 1/400 to 1/40. As expected, the cropped images were quite grainy due to ISO speed but I was happy to see that the focusing was much better than I had been achieving before. I tried the same test but this time set the ISO at 400 and got the same focusing results, but with the expected change in shutter speeds. The best results seem to be from f/8 to f/11 as was suggested to me earlier in this thread. I also took a series of shots with lens at 400mm and 300mm. These also showed a similar result, i.e. the lens focuses better with a smaller aperture. This I hope will help me to get better results than I have been getting. The conclusions reached are: I have been thinking too much about getting maximum light in and using high shutter speeds to freeze motion..!! Instead of just firing off shots I should try a few test shots and base my settings on the results of these..!! My next investment should be a sturdy tripod..!! Shots posted were all taken in raw format and are at ISO 400. They were taken straight from camera raw without any editing other than cropping before saving as jpegs. Photos are still grainy and far from perfect but they seem to be sharper at the aperture settings mentioned and are a huge improvement on all my other efforts at this magnification. Many things were learned today. Once again thanks to all for good advice, help and encouragement. It is very much appreciated.
Image at 500mm before cropping.
f/6.3
f/7.1
f/8
f/9
f/10
f/11
f/13
f/14
f/16
Weighted tripod. Not exactly practical for carrying around..!!
One more question if I may. I was asked by James to post a photo with Exif still attached. How would I go about doing this? Can they be embedded in the image file or do I need to copy them separately. My images are processed using Photoshop.
ps. No doorstoppers were harmed during this test. Mr Tiddles is safely back in his usual place by the sitting room door.!!