Sigma 150-500mm soft and/or front focusing?

Hey all,

This lens is new, and tried it out today...these are direct sooc RAW...it seems to be front focusing. I checked my AF point display, and they are on target in every picture.

Not sure what to change on 7D mf.... any ideas? I am not ruling out user error in anyway....

Maybe the DoF is just to small?

IMAGE LINK: http://www.flickr.com/​photos/jersfocus/69875​34626/

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IMAGE LINK: http://www.flickr.com/​photos/jersfocus/69875​35916/

....uploading to flickr with exif intact.

Here are some I hit with and tried to clean up in lightroom...not sure it they should be sharper at 500mm 1/6400

Using spot AF and spot focus...

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IMAGE LINK: http://www.flickr.com/​photos/jersfocus/71336​35789/

IMAGE LINK: http://www.flickr.com/​photos/jersfocus/69875​51312/

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I think some of them looks pretty sharp, the rest may be a user error or just OOF

With the exception of #3, the rest are sharp images of the birds. Not sure what you are complaining about.

cfcRebel wrote in post #14362772
With the exception of #3, the rest are sharp images of the birds. Not sure what you are complaining about.

OK well take these for example... its like they get a bit sharper when I upload to flickr or imgur...lol still though

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the last couple of shots you used ISO800, can't expect too much from the 7D....

Also you don't really need 1/6400 for them. Use ISO100, f8 and 1/2500 is more than plenty...

At the distances you appear to be shooting at I think atmospheric distortion is playing a part, heat haze from the ground also plays a part. As Scottie would say "Ye canna change the laws of physics"

Some of them do seem to be a bit soft so I would suggest you do some controlled test shots to make sure if it's front focussing. Also try stopping it down a bit, mine is sharp wide open at 500mm but is even better when stopped down to f8 - f11. Yours seems quite sharp at 500mm TBH, but you seem to be taking the photos at a large distance, it might be better trying to get closer before shooting.

I got this with a Canon 5DMkIII and Sigma 150-500 OS while it was having a rest. Taken at 1/800, ISO 1000 wide open at f6.3 @ 500mm at around 35ft distance. It's a Jpeg SOOC taken on a rare sunny day in April and is a crop of a crop.

IMAGE LINK: http://www.flickr.com …/67765667@N08/6​986734786/

500mm handheld is always a bit of a gamble, regardless of whether you've got OS. Add to that the ambiguity of the focusing system, movement of the subject and camera setup. Add to that the photographer's experience.

Practice, practice, practice.

Yes, I agree. I think there is nothing wrong with the lens related to front-focusing. This type of photography is difficult and it is hard to get a good percentage of keepers, there are so many variables and things that can go wrong. Keep doing it and use a tripod whenever possible.

With shutter speeds that high, I would turn off the OS. It's not helping, only slowing things down.

JersFocus wrote in post #14362794
OK well take these for example... its like they get a bit sharper when I upload to flickr or imgur...lol still though

Again, as far as focus is concerned, these 3 images still seem fine to me. Others have chimed in on several aspects that are valid, and you should look into that.

Keep the setting simple to begin with. Once you get a hang of it, then only wander off trying fancy settings.
For ducks and geese, start with:

• Av mode
  
• Set aperture to f8 (on sunny day like above)
  
• Spot metering
  
• Center Single AF point only
  
• Set ISO to 800
  
• Set Exposure Compensation to 0 for geese on ground, to +1 for Osprey inflight
  
• Use AI SERVO for moving geese and osprey

your last shots don't look to be good...but i can't tell why...it almost seems like it's a haze, or the fence behind them is where the focus point was...

i think your lens is probably fine based on the other shots...maybe a little under-exposed on the osprey...

Ok thanks for all the advice, great stuff, I love this forum. Knowledgeable posters willing to share information, whats not to love??!!

cfcRebel wrote in post #14366563
Again, as far as focus is concerned, these 3 images still seem fine to me. Others have chimed in on several aspects that are valid, and you should look into that.

Keep the setting simple to begin with. Once you get a hang of it, then only wander off trying fancy settings.
For ducks and geese, start with:

• Av mode
  
• Set aperture to f8 (on sunny day like above)
  
• Spot metering
  
• Center Single AF point only
  
• Set ISO to 800
  
• Set Exposure Compensation to 0 for geese on ground, to +1 for Osprey inflight
  
• Use AI SERVO for moving geese and osprey

I was pretty close to these settings (all but ai servo), I was not using AI SERVO (which I know in retrospect was a bad idea for inflight birds). I will try +1...it was a cloudy day yesterday and yes they came out underexposed.

To counter the light backlit bird, what is a good technique to get around the underexposure on subject without flash? Just boost EC? I tried bracketing which kind of does that..../shrug.