blue glow on whites

andy owen

andy owen

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Name
Andy
Edit My Images
Yes
what cause this? I took some pics of a hunt today. Really good daylight. Used my 70-200 f2.8 is and 50D.
when i reviewed them on pc i noticed this annoying blue glow around the white areas.

Also the images werent as pin sharp as I would have liked.

I used Aperture priority mode at f2.8, iso 200, white balance set to sunlight or cloud depending on conditions.



Please help.
Andy
 
i,ll leave this to one of the experts but i think it,s called fringing/ loss of detail

not sure if it,s the lens that causes it :shrug: thats it ca,s :agree:
 
How big a crop is it? It looks like, and I know this is going to be spelled incorrectly.... chromatic abberation, often red/purple fringing, caused by areas of high contrast:

edit: Looky here http://en.wikipedia.org/wiki/Chromatic_aberration

To be honest I wouldn't have expected it on an L series lens, but if there's a lot of contrast (and it's usually more apparent wide open), this MAY be the case. Never seen it blue before though, so it might be something else?
 
CA is an option but as has been pointed out, unlikely on L glass.

I'd suggest it's a slight blur from running in aperture priority and the camera slowing the shutter down to a speed below that recommended for the focal length you're using. This also fits with the images lacking sharpness.

Can you pick the shutter speed out of the exif? Think I'd have picked shutter priority for 1/250 or greater and bumped the ISO if necessary.
 
If you are shooting RAW this can be corrected in DPP.

David
 
AndWhyNot said:
CA is an option but as has been pointed out, unlikely on L glass.

I'd suggest it's a slight blur from running in aperture priority and the camera slowing the shutter down to a speed below that recommended for the focal length you're using. This also fits with the images lacking sharpness.

Can you pick the shutter speed out of the exif? Think I'd have picked shutter priority for 1/250 or greater and bumped the ISO if necessary.
Click to expand...

no mention of L glass in his profile i did look first :shrug:
 
AndWhyNot said:
I'd suggest it's a slight blur from running in aperture priority and the camera slowing the shutter down to a speed below that recommended for the focal length you're using. This also fits with the images lacking sharpness.
Click to expand...

I considered that too, but the shutter speed was 1/200, so I'd have though camera shake wouldn't have been too much of an issue (especially with IS), unless the subject was also moving pretty quickly.

Maybe the OP could have a look at other shots in similar situations and see if it's present there?
 
chris321 said:
I considered that too, but the shutter speed was 1/200, so I'd have though camera shake wouldn't have been too much of an issue (especially with IS), unless the subject was also moving pretty quickly.

Maybe the OP could have a look at other shots in similar situations and see if it's present there?
Click to expand...

he mentioned it was at a hunt so was this person on a horse even with( is) you,d need a pretty fast shutter speed to stop action/movement

nice to see the op has gone offline :clap:
 
AndWhyNot said:
CA is an option but as has been pointed out, unlikely on L glass.
Click to expand...

It is CA, L glass isn't immune to it, especially in a shot such as the one shown.
 


ok this is the original image for those who wanted to see it. the light was shining on him, he was standing still, I was in aperture priority and the settings were as follows:

F-Stop f/2.8
Exposure time 1/200
ISO 200
Exposure bias 0step
focal length 200mm
Metering mode Pattern

Im really confused on this one. I agree that in Aperture mode the shutter speed may have been a tad slow, which would explain the loss of detail, but the blue glow has got me stumped. The lens IS L glass by the way. Ive had this before when i took a shot of my house name sign (see below)



This is driving me nuts and i have to sort it as i have my 1st wedding this year.

Any suggestions will be greatfully recieved

Cheers guys
Andy
 
Willid1 said:
If you are shooting RAW this can be corrected in DPP.

David
Click to expand...

It's in the lens design, some situations will make it worse, software and PP are the only solution.

David
 
That house sign example looks like classic CA ( 'kin 'ell cottage??? ).

Cheers for posting the original and exif - the lack of sharpness is apparent. Since my last post a bit of googling has shown that another symptom of CA is a lack of sharpness. There you go.
 
so how do i improve the sharpness? maybe increase shutter speed? and bump up ISO? shoot in RAW?

Also, the settings on my 70-200 baffle me. What are the differences between stabiliser modes 1 and 2?
 
Chaz Photos said:
its all been said its CA the ACR will fix it and it will be sharper then One question I thought hunting had been banned
Click to expand...

Hunting foxes in this example has been banned. They hunt a synthetic (I believe) scent trail now instead.
 
Chaz Photos said:
its all been said its CA the ACR will fix it and it will be sharper then One question I thought hunting had been banned
Click to expand...

So has heroin and cocaine.
 
Classic CA - not because of the lens, but the sensor - areas of high contrast cause this - it's why the really expensive cameras are really expensive...

You don't get so much of this on the Pro-bodies, but I see it all the time from P&S, Bridge cameras and lower-spec DSLRs... (we have to sift all the rubbishy images from the Battlegroups before releasing them to the Press - sometimes a whole day can be spent looking at appalling OOF cheesy-snaps sent in by some Captain with a Coolpix).
 
Arkady said:
Classic CA - not because of the lens, but the sensor - areas of high contrast cause this - it's why the really expensive cameras are really expensive...

You don't get so much of this on the Pro-bodies, but I see it all the time from P&S, Bridge cameras and lower-spec DSLRs... (we have to sift all the rubbishy images from the Battlegroups before releasing them to the Press - sometimes a whole day can be spent looking at appalling OOF cheesy-snaps sent in by some Captain with a Coolpix).
Click to expand...

i disagree,
buy a tamron 70-300mm and you will get ca on any camera,
In optics, chromatic aberration (also called achromatism or chromatic distortion) is the failure of a lens to focus all colors to the same point. It occurs because lenses have a different refractive index for different wavelengths of light (the dispersion of the lens). The refractive index decreases with increasing wavelength.
http://en.wikipedia.org/wiki/Chromatic_aberration
 
scottthehat said:
i disagree,
buy a tamron 70-300mm and you will get ca on any camera,
In optics, chromatic aberration (also called achromatism or chromatic distortion) is the failure of a lens to focus all colors to the same point. It occurs because lenses have a different refractive index for different wavelengths of light (the dispersion of the lens). The refractive index decreases with increasing wavelength.
http://en.wikipedia.org/wiki/Chromatic_aberration
Click to expand...

Thanks - I know what it is and what it's caused by - I've been doing this for 35 years.
In this instance, I don't think it's caused by the lens, but by the sensor's inability to process the information correctly.
 
I was going to say sensor bloom in #21 but posted the link as it states "Image bloom from overexposure of CCD sensor (not applied to CMOS)" and the OP's camera has a CMOS sensor.
 
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