New Altair GPCAM First Light on a couple of DSOs

[Davesellars]

This is a great little camera - I bought the mono version thanks to Tring astro who were great about changing the first one quickly as it arrived with a large crack in the protective glass.  I'm primarily interested in DSOs and confess I'm just starting out with AP - i've had a go before with a DSLR  but wanted a dedicated little cam to start that I could use for auto-guiding duties with the DSLR and also on its own no guiding for smaller DSOs and trying out some black and white narrow-band imaging (just using a visual Astronomik UHC filter at the moment), but will get a H-alpha filter soon.

I had an opportunity on Saturday night while is was clear for a short while and picked up M11 and M16 both with a single 2 minute exposure and UHC filter using AltairCapture with its automatic dark frame integration.  Using the demo of Nebulosity 4 to post-process a little (don't really know what i'm doing in this department though I must confess!)

So, I've got a lot to learn but the results look reasonably promising especially if I do darks properly and stack multiple subs I'm sure I can get some decent results....

Taken with the Skywatcher 80ED (no focal reducer)

[Astrosurf]

I assume that you'll be using this for guiding only? Your DSLR will produce much better images with this cam doing the guiding. Try the cam just for solar system.

Let us know how you get on.

Alexxx

[Davesellars]

Depends on the object I think.  For smaller objects and starting to do some H-alpha narrow-band this camera otherwise using it to guide the DSLR for the larger stuff or where it would be really beneficial for much longer exposures.

[Astrosurf]

Good luck. Let us know how you get on.

[Twiggles]

Bought the colour version of this camera a short while back. While waiting for the planets to rise at a more social hour I also tried it out on a couple of DSO's. Had trouble with focusing a little and trying to find them, plus tracking issue with my EQ2 mount (yes I know, but its fine for planets!). I was quite impressed at its sensitivity but couldn't get any shots due to exposure times and the tracking issues with my mount. Still, I look forward to more practice with it and it was at least a useful excercise to try out the altair capture software, which I also found quite easy and intuitive to use.

[Davesellars]

HI Twiggles,

For one shot images bump up the gain and take some darks for automatic integration using AltairCapture first before capturing images.  You should get something worthwhile on a brighter object like some of the brighter globular clusters so i'd give these a go first.  A 30 second exposure generally showed quite a bit of detail on M2 for example with the gain at 700, your EQ2 with the tracking motor should be capable of at least that once it's properly polar aligned.  It would be interesting to see the difference between the colour and mono regarding the output.  Oh yes and for DSOs always shoot in 12 bit mode!

For focusing, yes I found this difficult and will be more-so given a shorter focal length.  I have yet to invest in one but a Bahtinov mask is really necessary.  For the setitngs of exposure and gain when focusing I captured 5 second images at a gain of 150 on a bright star (say magnitude 2 to 3 is a reasonably choice)  If you set the gain much higher the star will be bloated so you won't know if it's focused or not...  I need that Bahtinov mask to be perfect otherwise it is just guesswork!   Then, once you're focused lock it and go to the object you want to image...

Regards,

David

[Twiggles]

David,

late reply, finally got a chance to get out again. My alignment still isn't great but steadily getting better, the below shot was taken on the 26th September at 2200 with a rather bright moon! Exposure time was only five seconds due to mount alignment, and being an EQ2 it is very prone to vibration. Telescope used was a skywatcher 130 with 900mm focal length.

[Twiggles]

Image didn't load, second try, apologies.

[tomato]

Just ordered one principally for guiding but will definitely give it a try on some smaller DSOs.