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Finally - Dark Calibration for IQ3 Phase Backs can be switched off !

Stefan Steib

Active member
Just one Info that may be very interesting for People like me doing crazy stuff with cameras:

after drilling them on the last Phase Demo in Munich, they showed me the "aerial" setting of the New IQ3 on a XF camera , that essentially does what
I asked for maybe 20 years now: The dark calibration can now be switched off !!!

Hosianna !

Good things sometimes take a bit longer.....:thumbup:

Greetings from Germany
Stefan
 

dougpeterson

Workshop Member
Indeed it is old news.

And it's still not recommended as it will lower the quality of the end result.

The reason it's marked aerial is because it ensures consistent and fast shooting, which is mission critical for aerial (if it skips a single capture you need to loop the plane around again or even start the entire mapping over again).
 

voidshatter

New member
Indeed it is old news.

And it's still not recommended as it will lower the quality of the end result.

The reason it's marked aerial is because it ensures consistent and fast shooting, which is mission critical for aerial (if it skips a single capture you need to loop the plane around again or even start the entire mapping over again).
For IMX161 CMOS backs (e.g. IQ250) it will not lower the quality if you slide "Single Pixel" to 1 (out of 100) in Capture One - at least barely noticeable.

For CCD backs yes it may make the image unusable.
 

Wayne Fox

Workshop Member
Indeed it is old news.

And it's still not recommended as it will lower the quality of the end result.

The reason it's marked aerial is because it ensures consistent and fast shooting, which is mission critical for aerial (if it skips a single capture you need to loop the plane around again or even start the entire mapping over again).
seems like if the exposure is that long shooting an aerial the image would blurry, but i've never done aerial. Is it pretty normal for aerial shots to be long enough to trigger a dark frame subtraction? Irregardless, seems it doesn't need to be an "aerial" setting, and could be moved and labeled "turn of dark frame" setting - the aerial guys could certainly find it.

Also, can't a person shoot their own dark frame and subtract in post? I think this is where many of us would apply this ... doing a series of late light images, or for example doing continuous exposures to capture star trails. Does the camera do a better job? I realize the dark frame taken several minutes after several exposures have been made might not be quite the same for the early exposures because the sensor may be warmer and create more noise, but at least it allows you to capture the images you need to. A slight quality loss for some may be acceptable because at least you were able to get the shots. There are many cases where I'm shooting 30 sec to 1 min exposures in very early or late light, and I have a 3 or 4 minute window.
 

Paul2660

Well-known member
And I believe it really only matters on the IQ150, 250, and 350 i.e. CMOS backs. Turn it off on a CCD back, and pay the price in spades, with both excessive noise and stuck pixels. I have used my 260 up to 10 in this mode and after about the 3 exposure the noise starts to kick in. So I just leave it on as the overall quality of the image is vastly improved.

Paul C
 

Stefan Steib

Active member
Well for me that was new.

I just wonder - when Astronomy (maybe the better name for that setting) Photographers use premade dark calibration tables for certain exposures and temperatures
it works pretty well. Why not for the other people shooting that stuff ?

And a question for Doug - if that is all well known and old: where is the setting in Capture One to apply custom made dark tables ?

TIA
Stefan
 

yaya

Active member
seems like if the exposure is that long shooting an aerial the image would blurry, but i've never done aerial. Is it pretty normal for aerial shots to be long enough to trigger a dark frame subtraction?
Our aerial cameras can be set to adjust the shutter speed, aperture or ISO automatically, based on exposure evaluation in the camera and in iX Capture and you can set the lower and upper limits, just like on the XF. Think about doing a 3 hour run with an image taken every 3 seconds and the sun going in/ out etc. so being able to turn Dark Calibration off is a must.

BR
Yair
 

voidshatter

New member
Our aerial cameras can be set to adjust the shutter speed, aperture or ISO automatically, based on exposure evaluation in the camera and in iX Capture and you can set the lower and upper limits, just like on the XF. Think about doing a 3 hour run with an image taken every 3 seconds and the sun going in/ out etc. so being able to turn Dark Calibration off is a must.

BR
Yair
Can you confirm whether the Credo 50 can disable darkframe NR by any means please? From what I heard it looks impossible, forcing me to recommend IQ150 as minimum to my friends.
 

dougpeterson

Workshop Member
seems like if the exposure is that long shooting an aerial the image would blurry, but i've never done aerial. Is it pretty normal for aerial shots to be long enough to trigger a dark frame subtraction?
A dark frame is always triggered, unless the conditions of capture (shutter speed and temperature of the sensor) are close enough to the previous that it can be reused. Even at a fast speed like 1/1600th it will do a dark frame; it just isn't easy to notice since it only lasts 1/1600th of a second.
 

Wayne Fox

Workshop Member
A dark frame is always triggered, unless the conditions of capture (shutter speed and temperature of the sensor) are close enough to the previous that it can be reused. Even at a fast speed like 1/1600th it will do a dark frame; it just isn't easy to notice since it only lasts 1/1600th of a second.
I didn't know that. I assumed dark frame only kicked in at longer shutter speeds like most dSLR's.
 

Stefan Steib

Active member
Our aerial cameras can be set to adjust the shutter speed, aperture or ISO automatically, based on exposure evaluation in the camera and in iX Capture and you can set the lower and upper limits, just like on the XF. Think about doing a 3 hour run with an image taken every 3 seconds and the sun going in/ out etc. so being able to turn Dark Calibration off is a must.

BR
Yair
Thank you Yair for that Info - I didn´t even know that application exists. I see there is a download, can it be tested also for 30 days ?

Greetings from Germany
Stefan
 

yaya

Active member
Thank you Yair for that Info - I didn´t even know that application exists. I see there is a download, can it be tested also for 30 days ?

Greetings from Germany
Stefan
iX Capture is free but it only works with our aerial/ industrial cameras
 

ondebanks

Member
A dark frame is always triggered, unless the conditions of capture (shutter speed and temperature of the sensor) are close enough to the previous that it can be reused. Even at a fast speed like 1/1600th it will do a dark frame; it just isn't easy to notice since it only lasts 1/1600th of a second.
At a fast speed like 1/1600th sec, it's really a bias frame. It should not be called a dark frame when there has not been sufficient time for dark current to accumulate.

Anyway it's good to know that it can be switched off in the IQ3 backs.

It really should have been just as optional in the Phase One P+ backs. Contemporary backs from Kodak, Mamiya, Mosaic etc. all made this a crucial menu option.

I'm curious - did nobody ever use a P+ back for aerial photography? Would they not have faced the same issues?

Ray
 
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