sstan4you Loc: the little valley, ca

this is "sharp" for the sig @500mm

tinwhistle

I tend to agree with this comment regarding this lens, although I also have found that the focus point on the image in question is off to the right in the vicinity of the galvanized pipe. My personal summation of this image is: point of focus, pay close attention to your ISO and aperture settings and use a good tripod.

boberic Loc: Quiet Corner, Connecticut. Ex long Islander

As I am coming late to this party, if this has been mentioned before , forgive me. You said that this photo was made with a window beanbag. was the engine running? If so cars vibrate whe the engine is running, so this may be camera shake. Just saying

Madman Loc: Gulf Coast, Florida USA

Do you own or use a Sigma 150-500 lens? I assume that you do not because if you did and you couldn't get better quality photographs than the one shown by the OP with it, something is awfully wrong, either with you equipment or your skills.

I don't have one, but I have a brother that does. Both he and I can easily get extremely sharp, high quality images from it. Other members of this forum use this lens and regularly post excellent photos taken with it.

Your statement only fans the fire, it does nothing to help the OP solve his issue.

chaman

Well said. This is what is needed here!

greg vescuso Loc: Ozark,Mo.

I haven't read everyone's reply to your post so if someone already said this, sorry.
I have this lens and it does need a lot of light so being underexposed doesn't help. But l
Your focus is not really sharp anywhere and since you had the lens on a bag in a window I would bet you had the optical stabilizer switch on and that is why your image isn't sharp.

davidrb Loc: Half way there on the 45th Parallel

You've just about answered your own question. 500mm might be considered a little far for beanbag stability so you upped you shutter? Too fast for f/8 at 1/750 and ISO 400, don't you think? Your background gives that away, it's very blurred. The bird is not really sharp focus but the forward bar on the ladder is more so. On what was your focus? That might be your problem but you really need to get on a more stabilized platform, beanbags don't cut the mustard! If you are serious enough to be using 500mm lenses you should be more serious about on what you mount it. Even using a stable shooting platform you are asking your camera for a lot of luck. You were pressing that luck using those shooting parameters in less than bright sunlight. You were way under exposed when you did not need to be. What was your meter showing?

JCam Loc: MD Eastern Shore

Not sure I fully agree with you even though that is what many photographers preach. I consistently use upwards of 1/1000-1800+ at about 250mm with my Tamron 70-300 mm (perhaps with a higher that my usual ISO on hazy/dull days) when I'm on the boat to offset my and the subject boats both moving. It's the subject boats I want in sharp focus. If the background, boats or shoreline, are blurred so much the better; they are distractions from what I want to show.

Howard5252 Loc: New York / Florida (now)