The GetDPI Photography Forum

Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!

Shooting the Aurora with MF

markymarkrb

New member
I went out here in North Dakota last night to shoot the Aurora. It went ok using a 645DF/IQ180 with the 80mm LS. Most of my shots were at F2.8/ISO 200/8-10 seconds. The shots are ok but that is just it "ok" when it comes to IQ. Very grainy overall and all sorts of purple/brown lines and color casts. Has anyone else had any success getting some high quality shots using a similar setup? Right now I am thinking the IQ180 might just not be up for the task.

Mark
 

dougpeterson

Workshop Member
With the IQ series and other Dalsa-sensor backs you MUST use base ISO for long exposures to get good results.

The max 2 min exposure limit on this back applies to ISO35 at 68F. At higher ISOs or in warmer temperature the limit is much lower.

Also, Capture One v7 will do a much better job with the speckled single pixels that are produced from hitting the wall of long exposure limitations. It will also do a better job of rendering subtle color variations when Color NR is turned high. So if you haven't already, then try the single pixel noise reduction slider and other controls in v7 (make sure to upgrade the engine used on the image to v7 or you wont see any difference from v6). And just in case you or someone else reading this is tempted to try - ACR will do a horrid job on long exposure files compared to C1v6 or C1v7.

In either v6 or v7 you may find switching your color profile provides better color - in these situations where you are not in a traditional light source like outdoor daylite or tungsten there is no "correct" answer and switching between them may provide some different/better coloring.

In either v6 or v7 I prefer the rendering of long exposure files when luminance NR is turned down to 10-15 rather than the defaults. I also find adding a bit of grain (10-30 points) helps a lot with the overall atheistic, but this is a very subjective choice.

Also make sure NOT to use zero latency in this situation as it keeps the sensor active full-time which will build heat up which does nothing good for long exposures.

Also for best results when you are at the cusp of what the system can do it's best to provide a short break between shots in order for the heat on the sensor to dissipate. In other words if you shoot three one-minute shots right in a row the third shot will look like a 3-minute exposure. The heat will dissipate very quickly, so waiting 10-20 seconds will do a lot to minimize build up.

Also make sure to check the firmware of your back is up to date. Some progress has been made from the earliest firmware regarding power management and long exposure. Nothing huge, but worth checking (especially since there are several other large improvements to the UI and feature set with the current firmware versus earliest firmware).

Since you're on an open platform you can also rent, beg, borrow, steal, buy a P45+ which would be the best back (I'd argue best camera period, but I guess this is subjective) for photographing in this situation. It will work on any body an IQ180 would work on. We have several customers with an IQ and a P25+, P30+ or P45+ (all known for their great long exposures, especially the P45+) for just this reason.

If you do try a P45+ or if you were using v6 and now try v7 I'm sure we'd all love to see a post comparing the results.
 

dougpeterson

Workshop Member
Also, there is a 80/1.9 lens. It's not very sharp wide open, so I don't think it would be a good solution to this problem, but it's a fun/interesting/dirt-cheap lens so might be worth taking a shot at using this on a shot or two next time you have a chance. It would give you a natural gain in light gathering.
 
Top