Do I have a lens problem?
Dec 21, 2014 09:54:01 #
Jolly Roger wrote:
Let me throw an alternative theory into the mix:
If there is a gentle breeze coming from the deer's left and the deer exhales warm air on a cool day, there would be some heat haze coming up from the mouth and passing in front of its right eye.
On zooming in, on the download I suspect that is what the problem is.
If there is a gentle breeze coming from the deer's left and the deer exhales warm air on a cool day, there would be some heat haze coming up from the mouth and passing in front of its right eye.
On zooming in, on the download I suspect that is what the problem is.
Or the AI Servo picked up on the gently moving grass in front of the deer's nose and focused on that ... since that is where the focus point is at.
Dec 23, 2014 17:31:22 #
romanticf16
Loc: Commerce Twp, MI
Nightski wrote:
I do not know what front focussed is. Is it something that can be fixed?
It appears your camera focused on the grass in front of the deer rather than on the animal itself. Were you using multiple points of focus or spot focus? The multiple setting is more easily "distracted" by whatever appears in its sensors first, not necessarily the subject you wanted in sharp focus.
Dec 23, 2014 17:34:45 #
romanticf16
Loc: Commerce Twp, MI
oldtigger wrote:
we may be flogging a dead horse, at f 7.1 your camera/lens is diiffraction limited. you won't get a really sharp image no matter what you do.
You're kidding. The grass in the foreground is razor sharp. The multiple focus points just chose the wrong point of interest.
Dec 23, 2014 18:31:05 #
romanticf16 wrote:
You're kidding. The grass in the foreground is razor sharp. The multiple focus points just chose the wrong point of interest.
Yes ... we did figure this out .. I was in AI Servo .. focusing on a perfectly still deer with moving grasses all about. :wink:
Dec 31, 2014 23:31:52 #
Jan 8, 2015 11:43:33 #
Nightski wrote:
I shot this with my Sigma 150-500mm F/5.0-6.3 I po... (show quote)
Might be aperture. Every lens has a sweet spot where your focus will be right on. Other times not. Find the spot with the lens. Great shot.
Jan 10, 2015 07:19:54 #
dardan
Loc: Victoria
Nightski wrote:
This might sound like a silly question, but does this only happen in auto focus?
Back and front focus means that the camera/body combination focuses behind or in front of the point on which you are wishing to focus. This happens as a result of a mis-calibrated auto-focus system. In manual you get what you see.
Jan 10, 2015 07:27:07 #
dardan
Loc: Victoria
Nightski wrote:
I shot this with my Sigma 150-500mm F/5.0-6.3 I po... (show quote)
I don't think you have to worry, there is nothing wrong with the lens, you were simply not focused on the deer. The other shot is much better but both are a little overexposed and because the deer is in shadow the white balance is out.
Jan 18, 2015 12:00:53 #
Nightski wrote:
This might sound like a silly question, but does this only happen in auto focus?
The effect is front/back focusing problems. The cause would be the camera in auto (it looks for the best contrast, so if it errs...), your eye in manual (you look for the clearest image).
Jan 18, 2015 23:47:17 #
Wendy2 wrote:
I don't think it is a silly question, but I have no idea. I always shoot in auto focus because I can't trust my eyes to get it right.
My 70d makes the 'focus beep' when in manual mode, so maybe if you think it's front focused then turn the focus just a bit more while in manual? I'm not sure..
Jan 20, 2015 17:54:55 #
Nightski wrote:
I shot this with my Sigma 150-500mm F/5.0-6.3 I po... (show quote)
The vertical parallel blades of grass are causing an optical illusion. The deer's left eye appears to be brighter, clearer, and therefore sharper. The light source is from that side and is aiding in the affect.
Jan 20, 2015 18:52:43 #
davidrb wrote:
The vertical parallel blades of grass are causing an optical illusion. The deer's left eye appears to be brighter, clearer, and therefore sharper. The light source is from that side and is aiding in the affect.
Yes, I believe that's true and it's also true that my camera was focuse on a blade of grass just below the deer's nose on it's left side, thus the reason for the slightly oof right eye. My DOF didn't reach that far. As we discovered on page 2 by looking at my exif data, I was in AI Servo, thus the reason for the missed focus. The camera refocussed on the moving grass as that's what happens when the camera is in AI Servo .. it follows movement. So .. I learned something. Don't have my camera in Servo when focusing on a stationary animal on a windy day.
Jan 20, 2015 22:27:27 #
Nightski wrote:
Yes, I believe that's true and it's also true that... (show quote)
Glass is half full/ half empty! On the plus side, if the deer bolts you have it locked in focus! You might want to check the ops manual and see at what point the focus is going to switch from stationary focus to locking on motion. On some Canons that point is adjustable. You might be surprised to find your focus "problem" wasn't the cause of the image issue.
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