IR filter failures

Vitalii · 08-01-2014, 08:24 AM

Dear IR photography gurus. It is very hard to find some really bad and blown up IR pictures on internet. I really don`t know why, because I have plenty on my own.
I`m getting these ugly blue stripes from IR filter at longer shutter speed or higher ISO. These are not reflections, they are appearing independent of illumination.
Have somebody had same issues, or is there something wrong with me?

and the second question -
Why are the IR raw pictures double as big as the normal ones? Does it comes from much denser color gradation?

shooting with pentax k-x, 50mm 1.4, 28mm 2.8(Hotspot), adapt all Thamron 28mm 2.8, etc....

Last edited by Vitalii; 10-16-2014 at 01:50 PM.

VisualDarkness · 08-01-2014, 09:04 AM

Light from the viewfinder?

Vitalii · 08-01-2014, 09:59 AM

nope, allready tested. and sometimes there are less reflections in direct sunlight.

**jbondo** · 08-01-2014, 06:35 PM

How about if you intentionally rotate the filter 90 degrees? Also, have you tried taking the photo in an editor and blacking the red and green channels and cranking up the blue to see if you can make out an image/pattern? Shoot a featureless object (white wall, etc) and examine the pattern then.

adwb · 08-02-2014, 05:28 AM

Distant memory from a photo show where I was going to buy a IR filter at a stand the salesman told me it won't work properly with some pentax bodies

Vitalii · 08-03-2014, 10:24 AM

And the problem waaaaas... ... ... Light from viewfinder - VisualDarkness was totaly right.
Funny thing is, that I´ve already tested it ones, and it doesn´t help, but i tried it ones more to be sure and it helped. next buy will be a propper viewfindercap, though my hat is doing it just fine.

and the second part why are the IR pictures heavier?
Tried today some macros with Reversed Schneider Kreuznach Edixa-xenon 50mm f1.9 Raw file size, completly same composition.
out of focus 13,9MB
focus 10,5MB
IR 15,3MB
seems that the OOF Picture is much noisier than the focused one - more noise - more complex information. something same with IR. other thoughts?

**jbinpg** · 08-04-2014, 07:33 PM

Yes, viewfinders can be leaky with long exposures. My tests with my K-3 are detailed in this thread:

https://www.pentaxforums.com/forums/29-welcomes-introductions/268543-hello-lo...profiling.html

08-01-2014, 08:24 AM	#1
Vitalii Senior Member Join Date: May 2014 Posts: 115	IR filter failures Dear IR photography gurus. It is very hard to find some really bad and blown up IR pictures on internet. I really don`t know why, because I have plenty on my own. I`m getting these ugly blue stripes from IR filter at longer shutter speed or higher ISO. These are not reflections, they are appearing independent of illumination. Have somebody had same issues, or is there something wrong with me? and the second question - Why are the IR raw pictures double as big as the normal ones? Does it comes from much denser color gradation? shooting with pentax k-x, 50mm 1.4, 28mm 2.8(Hotspot), adapt all Thamron 28mm 2.8, etc.... Last edited by Vitalii; 10-16-2014 at 01:50 PM.

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08-01-2014, 09:04 AM	#2
VisualDarkness Veteran Member Join Date: Nov 2011 Location: Uppsala, Sweden Photos: Gallery Posts: 4,439	Light from the viewfinder?

08-01-2014, 09:59 AM	#3
Vitalii Senior Member Join Date: May 2014 Posts: 115 Original Poster	nope, allready tested. and sometimes there are less reflections in direct sunlight.

08-01-2014, 06:35 PM	#4
jbondo Loyal Site Supportaxian Join Date: Sep 2013 Location: Texas Photos: Albums Posts: 503	How about if you intentionally rotate the filter 90 degrees? Also, have you tried taking the photo in an editor and blacking the red and green channels and cranking up the blue to see if you can make out an image/pattern? Shoot a featureless object (white wall, etc) and examine the pattern then.

08-02-2014, 05:28 AM	#5
adwb Veteran Member Join Date: Sep 2009 Location: Bristol UK Photos: Gallery Posts: 1,636	Distant memory from a photo show where I was going to buy a IR filter at a stand the salesman told me it won't work properly with some pentax bodies

08-03-2014, 10:24 AM	#6
Vitalii Senior Member Join Date: May 2014 Posts: 115 Original Poster	And the problem waaaaas... ... ... Light from viewfinder - VisualDarkness was totaly right. Funny thing is, that I´ve already tested it ones, and it doesn´t help, but i tried it ones more to be sure and it helped. next buy will be a propper viewfindercap, though my hat is doing it just fine. and the second part why are the IR pictures heavier? Tried today some macros with Reversed Schneider Kreuznach Edixa-xenon 50mm f1.9 Raw file size, completly same composition. out of focus 13,9MB focus 10,5MB IR 15,3MB seems that the OOF Picture is much noisier than the focused one - more noise - more complex information. something same with IR. other thoughts?

08-04-2014, 07:33 PM	#7
jbinpg Site Supporter Join Date: Mar 2008 Location: Prince George, BC Photos: Gallery \| Albums Posts: 3,546	Yes, viewfinders can be leaky with long exposures. My tests with my K-3 are detailed in this thread: https://www.pentaxforums.com/forums/29-welcomes-introductions/268543-hello-lo...profiling.html