What is this artifact?

Started Jan 26, 2013 | Questions
Spazmedia
Regular MemberPosts: 173Gear list
Like?
What is this artifact?
Jan 26, 2013

Just got a Sony NEX-6 which I have been enjoying. The image quality is top notch though the menus are terrible. (At least coming from Nikon and Canon).

One odd thing though came out in a picture taken of my daughter. There some strange artifact on the green part of the shirt. Is this moire? Hopefully you can see it from this crop and the image is not being re-sized by dpreview site.



 Spazmedia's gear list:Spazmedia's gear list
Nikon D100 Canon EOS 7D Sony Alpha NEX-6 Canon EF 50mm f/1.4 USM Canon EF-S 18-200mm f/3.5-5.6 IS +6 more
ANSWER:
uhligfd
Senior MemberPosts: 1,354
Like?
Re: What is this artifact?
In reply to Spazmedia, Jan 26, 2013

Have a look at the shirt, maybe it is of a ribbed cotton material and that is what you are seeing.

Reply   Reply with quote   Complain
Lightshow
Senior MemberPosts: 2,656Gear list
Like?
Re: What is this artifact?
In reply to Spazmedia, Jan 26, 2013

Yes that's what it is, it happens when fine details and the pixel structure have lines/mm that are close, 1:1 - 2:1

A little local blurring where the effect shows will tone it down, the same effect the alias filter does, or is supposed to do as in this case.

 Lightshow's gear list:Lightshow's gear list
Sony Alpha NEX-7 Sony Alpha 7R +1 more
selected answer This post was selected as the answer by the original poster.
Reply   Reply with quote   Complain
Green_Thark
Contributing MemberPosts: 988
Like?
Re: What is this artifact?
In reply to Spazmedia, Jan 26, 2013

Was this jpeg or RAW if RAW what did you use to convert?

Looks like the demosaicing has gone a bit squiffy. might just be the thread pattern on the shirt, but I'd keep an eye on it, if you see this pattern often it might be a fault.

-- hide signature --

Always keep your words soft and sweet, just in case you have to eat them

Reply   Reply with quote   Complain
Spazmedia
Regular MemberPosts: 173Gear list
Like?
Re: What is this artifact?
In reply to uhligfd, Jan 26, 2013

uhligfd wrote:

Have a look at the shirt, maybe it is of a ribbed cotton material and that is what you are seeing.

That's what I thought at first but its just regular old cotton weave. Thanks anyways for the suggestion.

 Spazmedia's gear list:Spazmedia's gear list
Nikon D100 Canon EOS 7D Sony Alpha NEX-6 Canon EF 50mm f/1.4 USM Canon EF-S 18-200mm f/3.5-5.6 IS +6 more
Reply   Reply with quote   Complain
Spazmedia
Regular MemberPosts: 173Gear list
Like?
Re: What is this artifact?
In reply to Lightshow, Jan 26, 2013

Lightshow wrote:

Yes that's what it is, it happens when fine details and the pixel structure have lines/mm that are close, 1:1 - 2:1

A little local blurring where the effect shows will tone it down, the same effect the alias filter does, or is supposed to do as in this case.

That's surprising (amazing almost!) given I was shooting handheld and the ISO was at 1000. I guess this supposedly not so sharp lens is quite sharp! Thanks for the help.

 Spazmedia's gear list:Spazmedia's gear list
Nikon D100 Canon EOS 7D Sony Alpha NEX-6 Canon EF 50mm f/1.4 USM Canon EF-S 18-200mm f/3.5-5.6 IS +6 more
Reply   Reply with quote   Complain
Spazmedia
Regular MemberPosts: 173Gear list
Like?
Re: What is this artifact?
In reply to Green_Thark, Jan 26, 2013

Green_Thark wrote:

Was this jpeg or RAW if RAW what did you use to convert?

Looks like the demosaicing has gone a bit squiffy. might just be the thread pattern on the shirt, but I'd keep an eye on it, if you see this pattern often it might be a fault.

-- hide signature --

Always keep your words soft and sweet, just in case you have to eat them

Shooting JPG. Thanks for the info!

 Spazmedia's gear list:Spazmedia's gear list
Nikon D100 Canon EOS 7D Sony Alpha NEX-6 Canon EF 50mm f/1.4 USM Canon EF-S 18-200mm f/3.5-5.6 IS +6 more
Reply   Reply with quote   Complain
ZhanMInG12
Forum MemberPosts: 56Gear list
Like?
Re: What is this artifact?
In reply to Spazmedia, Jan 27, 2013

I think that might be the in camera noise reduction at work in an unpleasant way.

Better to shoot raw and then use software to control the amount of reduction

-- hide signature --

too lazy for DSLRs:-)

 ZhanMInG12's gear list:ZhanMInG12's gear list
Fujifilm FinePix X100 Canon EOS 7D Canon EOS 600D Sony Alpha NEX-7 Sony Alpha 7R +7 more
Reply   Reply with quote   Complain
Keyboard shortcuts:
FForum MMy threads