More on Watec Galaxies (+ Camera settings)

[Macavity]

Impressed by Mike B's screenshots of Galaxies, I thought I'd add one of mine, plus a bit on Camera / Software settings - All in the cause of science etc. So, in deference, and with thanks for the incentive...

The main difference: I believe Mike is using a (lovely!) CPC 1100, focal reduced to f/3.3,

whereas I'm using a more "stick & string" TS/GSO 8" - f/4 Photo-Newt.

Aperture-wise, he should get (11" / 8")^2 = 1.89x

F/stop-wise: (4/3)^2 = 1.46x GRAND total = 2.76x !

So, effectively, his "light gathering" is 2.76x that of mine? In other words, over ONE (2.51x) magnitude more.

Superficially not much but, as we know, image-wise, "every little helps"?

Anyway, here's my genuine (Honest, Guv!) effort on M99, from last night. The Watec 120N+ control box was on the "Slow" setting #8 (128x 1/50s frames integrated), Gain was 80% & the Gamma was set to "Lo". In the Gstar4 software, I used "default" camera settings, but (notably) MAXIMISED the contrast slider!

1. Basic SINGLE screenshot in real time:

2. Stacked / processed image of 256 frames:

Conclusion: In real time, with my setup, I am on the threshold of "random noise" with the *fainter* stuff? But it's still possible to see structure in galaxies. No excuses, but it would seem that M99 has a surface brightness of +13, so maybe not the easiest of targets? A "pretty one", but then I don't know my galaxies well yet!

Aside: Whether the antithesis of VIDEO astronomy or not, a bit of stacking and post-processing can be

FUN and productive? But I might need to (Doubtless still can) work on the latter... and Watec "settings"!

Macavity / Chris

P.S. Apologies for the long post! I'd love to hear of others' experiences - "Settings" etc. Still finding VIDEO Astronomy a considerable source of inspiration here... Hopefully more "good nights" in prospect for us ALL!

[mike.brightmore]

Hi Chris

The real test for me is how much more you can see with video enhancement compared to visual. I suffer from light pollution and ageing eyesight so for me the difference is considerable. Without video my range of targets would be massively reduced. Another serious consideration for me is that I still want to be observing after I get the telegram from Her Majesty, so am trying to set things up now for that eventuality - video, remote operation, wheelchair access etc. Well its much more fun than planning stair lifts, bath cranes and raised toilet seats.

Thanks for the info about settings. I still haven't got to grips with them all yet. Have you ever used the Iris setting on the Watec? What software are you using for video grab?

Nothing wrong with your M99. The shape and structure are clear, which is not easy for face-on galaxies. Last night wasn't very transparant either - I tried for M95 and it was rubbish.

I think that video astronomy still has a long way to go and a lot more potential to realise. I wrote a letter about it to the Sky at Night mag three years ago (and got a lovely box full of books for the letter of the month) and even that short while ago hardly anyone had heard of it. Come to think of it I don't think anyone has written a book on video astronomy yet but correct me if I'm wrong.

[Macavity]

Hi Mike - Thanks for the reply.

It's certainly great to apply two (or more!) heads to these questions. Getting ready for "another go" tonight, hopefully. But meanwhile, in brief...

A genuinely good book is:

Deep-Sky Video Astronomy Patrick Moore's Practical Astronomy Series: Amazon.co.uk: Steve Massey, Steve Quirk: Books

Up to date, and orientated to relevant (Watec etc.) hardware + software.

The "Iris" switch is to enable auto-iris control of C-thread security camera lenses etc., via the socket on the side of the Watec. A random website illustrating the cabling?

DeepSpacePlace - Meteor Camera

For VIDEO Capture etc., I use a generic "EasyCap" USB dongle:

EasyCAP USB 2.0 Video and Audio Capture Card: Amazon.co.uk: Computers & Accessories

Mixed reviews, but seems to work for me!

Personally, I use the "Gstar4" capture software:

GSTAR - EX Deep Sky Planetary CCD Camera

Their camera is functionally the same as the Watec?

Looks like we have similar goals re. our "dotage"! LOL. Revisited your obsy. pics too. Great setup. More anon, if anything else occurs to me?

Chris/Macavity

[mike.brightmore]

Some really useful information there Chris. Thanks. Because the Watec has always done what I got it for I've never properly tried to get more out of it. Will let you know how I get on.

Mike