P65+ Noie issue @ 800 ISO please help

[Paul2660]

The other thing to remember, is that CCD backs, really don't have a "high ISO" like CMOS, you are just changing the metadata, it's not doing anything on the chip.  This is one little issue that have never really been explained in great depth, but CCD MF backs, are really just base ISO, whatever that is anything else is risk you are not changing anything on the chip by increasing ISO.  The only thing that really does is Sensor plus, where you get 4:1 and the high ISO is quite acceptable due to the fact that 4x the amount of light has now been used, however at the cost of overall resolution. 

Net, if want to push your exposure by increasing the ISO, not exposure the end result will have a lot of noise, i.e 1/30 of a sec at ISO800 vs 1/8 of a sec or 1/4 of a sec at ISO 50. 

Exception to this was the IQ260, which does offer a true higher ISO setting for long exposures @ ISO 140, but that back suffers the same as the P65+ much past ISO400, at least mine did.  There is NO gain however is use of the long exposure mode LE on the IQ260 to attempt to get a cleaner high ISO, (nothing is gained by using LE mode ISO400, 800 over non LE mode ISO 400/800), believe me I tried to make it work for several years.

Paul Caldwell

[TonyVentourisPhotography]

Your post  reminds me of a review of the P45 from a while ago.  It was shown that it really only had an ISO of 50 or 100.  Everything else was just the same as raising the exposure in post processing.

The quality of light sometimes has a part in the image too.  I've seen spectacular images from my back in good light, and some absolutely horrendous noise and color in poor lighting.  Even with a decent exposure. 

[Paul2660]

Hello Tony,

I fully agree, that in the right conditions, the CCD backs can produce amazing images.  It just has always bothered me how many people are led to believe (and I was one of them) that the CCD technology has the same ISO stepping that CMOS allows and it's just not true.  There is basically no amplification possible as I understand it.  Dalsa and P1 did a lot with the sensor plus (but that is still not amplification just binning) and then P1 and Dalsa tried again with the IQ260, and the LE mode (which IMO was a failure past 10 minutes). 

That being said, what could be achieved with the P45+ at 45 minutes to 1 hour at base ISO of 50 was close to amazing and IMO still outdoes a lot of current CMOS cameras in those exposure ranges (which is why I always stack)

Paul Caldwell

[eronald]

Your post  reminds me of a review of the P45 from a while ago.  It was shown that it really only had an ISO of 50 or 100.  Everything else was just the same as raising the exposure in post processing.

The quality of light sometimes has a part in the image too.  I've seen spectacular images from my back in good light, and some absolutely horrendous noise and color in poor lighting.  Even with a decent exposure.

All true, but the op's back is drifting over time; this is a hardware issue with that sample.

Edmund

[Rob_Strovich]

Hello,

I had the same issue some times ago. Send the back to P1, it came back with the same issue again and I refused to pay for the so called "recalibration" of the back. In the end after several email from my dealer and P1 they said there was a problem with C1 making an overcorrection of my files (I was with C1 8 if I correctly remember... ). One solution they gave to me was to put a string after the name of my folder so C1 will stop to overcorrect those files (if your folder was "raw" you called it instead "raw P1#1024-OFF#"). Weird ah? At the moment my back works good, I have tried a 800iso shot in C1 10, no traces of patterns on the CCD unions, just a bit of color blobs, but that's the reality with CCD backs. I can use it for my taste until 200iso or 400iso for BW portraits, in which grain is good in my opinion, not the same for the colors.

I send you a link to a 800iso image, so you can see what my back is doing... https://we.tl/YoLoROVN5F

Good luck!

Rob

www.pastrovicchio.com

[wellcome86]

Hello,

I had the same issue some times ago. Send the back to P1, it came back with the same issue again and I refused to pay for the so called "recalibration" of the back. In the end after several email from my dealer and P1 they said there was a problem with C1 making an overcorrection of my files (I was with C1 8 if I correctly remember... ). One solution they gave to me was to put a string after the name of my folder so C1 will stop to overcorrect those files (if your folder was "raw" you called it instead "raw P1#1024-OFF#"). Weird ah? At the moment my back works good, I have tried a 800iso shot in C1 10, no traces of patterns on the CCD unions, just a bit of color blobs, but that's the reality with CCD backs. I can use it for my taste until 200iso or 400iso for BW portraits, in which grain is good in my opinion, not the same for the colors.

I send you a link to a 800iso image, so you can see what my back is doing... https://we.tl/YoLoROVN5F

Good luck!

Rob

www.pastrovicchio.com

Hi Rob,

Could you describe exactly how you have been disabling the auto correction? Do I have to rename the file or the folder?
thx

[Rob_Strovich]

Hi,

just add a space and the string P1#1024-OFF#. the folder "Capture" becomes "Capture P1#1024-OFF#".

Then you open C1 and try if it works...

Rob

[Rob_Strovich]

You have to rename the folder which contains the raw files only, not the single files...