Focus test and noticed something

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forceofnature

Guest
Was just checking focus area on lens. When I changed this to PNG image from RAW you can see a black speck on the touch pad. I thought my lens or sensor had a spot but looked at the RAW image and it was clean. I was using GIMP to convert, so I wonder if it is a compression artifact or error. Just trying GIMP again with my Linux hard drive.

Anyone see anything like this before

1200689838_eftB8-L.png
 
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DEEKAYPEE8569

DEEKAYPEE8569

Well-Known Member
forceofnature said:
Was just checking focus area on lens. When I changed this to PNG image from RAW you can see a black speck on the touch pad. I thought my lens or sensor had a spot but looked at the RAW image and it was clean. I was using GIMP to convert, so I wonder if it is a compression artifact or error. Just trying GIMP again with my Linux hard drive.

Anyone see anything like this before

1200689838_eftB8-L.png
Click to expand...

Thie pic looks dark; as if it was taken without flash. I didn't notice the black speck you mention. Perhaps the black speck is a product of the camera trying to compensate for there being no discernable flash by pixelating what it could not focus on? :shrug:
 
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J

JimD_K10D

Pentaxian
Not familiar with GIMP but its either one of two things:

1. An error - its too far off surrounding colors to be a normal compression artifact.

2. If it has a "paint" feature you accidentally painted a black dot on it.
 
F

forceofnature

Guest
JimD_K10D said:
Not familiar with GIMP but its either one of two things:


2. If it has a "paint" feature you accidentally painted a black dot on it.
Click to expand...

Actually this might be the answer. I make have tapped the touch pad in that area and not noticed.

Yes it was taken without flash in a dark room. I was just testing low light focusing and accuracy.
 
F

FMarquart

New Member
forceofnature said:
Actually this might be the answer. I make have tapped the touch pad in that area and not noticed.

Yes it was taken without flash in a dark room. I was just testing low light focusing and accuracy.
Click to expand...

I took a look at the original and compared them to the photo of your wife, orange, and light shade that you shot with the 1D Mark III and it doesn't show up there, so it indicate it's NOT a burned out pixal, because its not showing up on the other photos...

Frank
 
F

forceofnature

Guest
FMarquart said:
I took a look at the original and compared them to the photo of your wife, orange, and light shade that you shot with the 1D Mark III and it doesn't show up there, so it indicate it's NOT a burned out pixal, because its not showing up on the other photos...

Frank
Click to expand...

Yes I looked there too. I also compressed the others in jpg.

Anyway its fun learning the new camera. I am just glad I think the focus is getting nailed down and now I need to start learning the other features on it for multi exposures etc. This f/1.2 lens is frustrating as it needs micro adjusting wide open by -4 then at f/2.8 0 adjustment.
 
jbr13

jbr13

www.jbr.smugmug.com
forceofnature said:
Yes I looked there too. I also compressed the others in jpg.

Anyway its fun learning the new camera. I am just glad I think the focus is getting nailed down and now I need to start learning the other features on it for multi exposures etc. This f/1.2 lens is frustrating as it needs micro adjusting wide open by -4 then at f/2.8 0 adjustment.
Click to expand...

Force, what kind of setup are you using to test and adjust your autofocus?
 
F

forceofnature

Guest
jbr13 said:
Force, what kind of setup are you using to test and adjust your autofocus?
Click to expand...

I printed out a similar image Jim mentioned in the previous message. If you have something better I am interested.
 
jbr13

jbr13

www.jbr.smugmug.com
Force, Doing a calibration with the method you have used is not really a prefered method. Here is a link that you can rent a very good adjustment tool. It works great and you can be much more confident in your calibration.


LensAlign Pro Focus Calibration System


Good luck,
 
jbr13

jbr13

www.jbr.smugmug.com
Yeah, a buddy of mine rented it for a week. It works great and between the two of us, we did three camera and about 10-13 lenses. It does take a little time to set everything up, but we did all our gear in about 5-6 hours.


I have two new lenses and will probably rent one again in a few months!
 
F

FMarquart

New Member
jbr13 said:
Yeah, a buddy of mine rented it for a week. It works great and between the two of us, we did three camera and about 10-13 lenses. It does take a little time to set everything up, but we did all our gear in about 5-6 hours.


I have two new lenses and will probably rent one again in a few months!
Click to expand...

Jason,

Don't rent one I have it...Let me know if you need to borrow it...

Frank
 
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