Questions about AIP4WIN vs IRIS for DSLR photometry

Affiliation

Astronomical Society of South Australia (ASSAU)

Thu, 01/28/2021 - 12:47

I've been using IRIS on WINE on a Mac (32 bit OS; old machine) for quite awhile but given the recent licensing change for AIP4WIN (which is great), I'm considering switching. It also seems to run just fine under WINE.

I have a few questions though.

IRIS allows creation of a dummy dark for short DSLR exposures. Does AIP4WIN also allow this? The software tutorial is not clear on the matter.
The last part of the AIP4WIN software tutorial shows the align and stack feature. IRIS has these as separate features. Can one just align without stacking in AIP4WIN?
The AIP4WIN tutorial talks about the conversion from raw (e.g. CR2) to Adobe DNG then later from DNG to FITS in a one image by one approach. I'm thinking that going straight from CR2 to FITS via something like https://github.com/eaydin/cr2fits (scripting approach) would be good, rather like IRIS's somewhat more awkward convertraw command. Thoughts?

I could of course just see how far I can get, but I thought I'd ask given the wealth of experience here.

IRIS has a limit of 5 comp stars so a couple of rounds per filter is required. For awhile I've been using a Python notebook I cobbled together to take the calibrated images from IRIS and get instrumental mags somewhat faster that way before the usual spreadsheet approach (https://www.aavso.org/dslr-camera-photometry-guide), although that could be replaced in the notebook with some time and effort too. I suspect it's been done already though too.

Anyway, AIP4WIN does not appear to have that comp star maximum limit, which is cool so I'm keen to give it try.

Thanks.

David

Mark Blackford

Affiliation

Variable Stars South (VSS)

Thu, 01/28/2021 - 21:21

Questions about AIP4WIN vs IRIS for DSLR photometry

Hi David,

It has been a few years since I used AIP4Win to process DSLR images so I'm a little rusty. To answer your questions:

1) You can make a dummy dark in AIP4Win by selecting File/New/Blank image then inputting the appropriate values.

2) I don't know if you can just align in AIP4Win, buy why would you want to? AIP4Win can find the right stars in a series of images even if there is significant drift from one image to the next.

3) Batch conversion direct from CR2 to FITS would make things a lot easier. I haven't tried cr2fits but if it can do the job efficiently and accurately that would be great. Check that FITS header info is correct.

Let us know how you get on.

If you haven't already, you should check out the AIP4Win@groups.io forum.

Cheers,

Mark

spp

Affiliation

American Association of Variable Star Observers (AAVSO)

Thu, 01/28/2021 - 23:20

"Can one just align without stacking in AIP4WIN?"

Yes. It is call the Register Images tool. I think you'll find it in the Multiple Images drop down menu. If you search the installed AIP Help directory you'll find the instructions.

Phil