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1min exposure with IQ160 ?

archivue

Active member
Hi everyone !

Can someone show crops from 1min exposure with an iq160 back ?

how does it perform at 1min vs P45+ ?

thanks
 

dougpeterson

Workshop Member
At ISO 50 you can barely pull off 60 seconds from an iq160 at room temperature.

I'd put the practical limit for high quality at more like 40 seconds.

Whereas the p45+ is barely breaking a sweat at 1 min and can very easily go much longer.
 

Paul2660

Well-known member
Having owned both the 45+ and 160, the 160 will be pretty much gone past 35 seconds. If you can shoot in outdoor temps below 60 degree F you might get bit longer from the 160.

What I would like to see are more longer exposures from the IQ260.

Too warm here to do any testing.

Paul
 

Ken_R

New member
I put the limit on my IQ160 at 20 seconds in temps 55F and above. I have not used it in lower temps. The file starts to get noisier and noisier after that. IMHO its best to keep exposures to 10-15s max.
 

torger

Active member
Not tested the IQ160 but as a note from someone that sometimes shoots at temperatures as low as -30C (-22F) I can say that temperature does make a large difference in how noisy the file becomes, as the noise is heat-related. In the winter the longer exposures get substantially cleaner :)
 

GrahamWelland

Subscriber & Workshop Member
One minute with the IQ160 at room temperature will have lots of hot pixels. I could use it but typically only with long exposures converted to b&w and aggressive noise reduction. When I had my 160 I also purchased a P25+ specifically for those long multi-minute exposures.
 

marktomaras

New member
I just shot some 20 and 30 second exposures with my IQ160, on a warm Miami evening outdoors, this was before I saw this thread. The photos were absolutely showing a loss of pixel-peeping detail. I was quite disappointed. The shot was an ordinary, post card plain, city skyline with water in the foreground. The buildings were quite distant, so when you zoom in to 100%, the windows remain small enough that one cannot really see inside them. Now that you can imagine the shot, the issue I have is that the edges of the windows, which should have a sharp edge, get a mushy, splotchy look. It is not up to standards for me. I suppose I will have to shoot at faster speeds.

Does anyone know if heat buildup causes noise and detail loss to set in at faster speeds too? If I shoot 50 exposures at 5 seconds each in warm weather, will the heat hurt the latter exposures in the series?
 

dougpeterson

Workshop Member
I just shot some 20 and 30 second exposures with my IQ160, on a warm Miami evening outdoors, this was before I saw this thread. The photos were absolutely showing a loss of pixel-peeping detail. I was quite disappointed. The shot was an ordinary, post card plain, city skyline with water in the foreground. The buildings were quite distant, so when you zoom in to 100%, the windows remain small enough that one cannot really see inside them. Now that you can imagine the shot, the issue I have is that the edges of the windows, which should have a sharp edge, get a mushy, splotchy look. It is not up to standards for me. I suppose I will have to shoot at faster speeds.

Does anyone know if heat buildup causes noise and detail loss to set in at faster speeds too? If I shoot 50 exposures at 5 seconds each in warm weather, will the heat hurt the latter exposures in the series?
Check your noise reduction settings in c1; turn them down and detail will come back (along with increased grain).

Yes, anytime the sensor is exposing it is warming up. In your example the last frame will be noisier than the first. Not much time is required to dissapate that heat though.

For any long exposure work it's important to avoid zero latency mode.
 

Paul2660

Well-known member
I just shot some 20 and 30 second exposures with my IQ160, on a warm Miami evening outdoors, this was before I saw this thread. The photos were absolutely showing a loss of pixel-peeping detail. I was quite disappointed. The shot was an ordinary, post card plain, city skyline with water in the foreground. The buildings were quite distant, so when you zoom in to 100%, the windows remain small enough that one cannot really see inside them. Now that you can imagine the shot, the issue I have is that the edges of the windows, which should have a sharp edge, get a mushy, splotchy look. It is not up to standards for me. I suppose I will have to shoot at faster speeds.

Does anyone know if heat buildup causes noise and detail loss to set in at faster speeds too? If I shoot 50 exposures at 5 seconds each in warm weather, will the heat hurt the latter exposures in the series?
The single biggest issue the 160 will have in your environment is the outside humidity/temp in Miami. I work in Arkansas and in the summer, longer exposures with a CCD back really won't work. The heat build up on the back is extreme, and you can feel the heat on the case of the IQ.

The one thing I have learned to do any time I shooting 1 sec to 10 sec is to clear the registers of the back, I do this by taking a 1/500 sec shot. For some reason this seems to allow the 260 to have a cleaner file the next time. You waste a shot of course but with CCD you just don't have a lot of options.

You can always look to the P45+, as it's going to give the best long exposure of any CCD back out there, including the "260" which can't come close. The P45+ in temps of 69 degree F or lower can do a great 1 hour exposure, really still the top in the lineup. With the 260, in the same conditions, you may get 15 minutes of a file after that the noise is really extreme along with stuck pixels. The other option is the CMOS solution, but it has its own set of issues. The bigger issue with the CCD is the mediatory dark frame which you have to shoot or the noise will be really terrible. This can cut into your shooting time quite a bit. With the CMOS backs, you can shoot in "aerial" mode and this kills the dark frame.

Also as Doug mentioned don't use zero latency as that keeps the back on 100% and it will heat up quickly.

Another rule of thumb, if the top plate is hot, then don't try a long exposure, turn it off of a while and then try again. Heat = noise with CCD.

Paul
 
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