M51 Binning test

[RobertM]

This was a trial to see how much difference binning would make.  The subs were taken at 2x2 and rescaled to full res before being calibrated and processed.  It's probably lost some resolution but is the setup and conditions good enought for that anyway - I very much doubt it.  I know it's badly framed but I had just finished M63 and all the flats were taken with the image train in that orientation.

http://gallery.orpington-astronomy.org.uk/displayimage-449.html

Thanks for looking

[JohnP]

Wow Robert - for a test that's pretty awesome.. only wish I had a camera with a chip that was big enough so that when I binned 2X2 I still had reasonable resolution.... if I bin mine I end up with 320X240....

That's a cracking shot..

John

[MarkS]

Robert,

That is definitely an excellent image - what an interesting experiment.  So you've performed 2x2 binning but maintained full resolution for the final image.

Mark

[RobertM]

Yes it's strange the way it came out so well considering.  The individual frames did not look like they had that sort of potential but the stars were dancing a bit so I decided to try it out.  It also had the positive effect of shortening the exposure times - 10x2mins + 10x5mins for a total of 70 minutes luminance.  The jpeg does seem to have lost some of the tail from NGC5195 as it goes out to the edge of the frame, I guess that's the conversion algorithm.

[Rocket Pooch]

Very nice, so are you now happy with all the kit or is a 4mpix camera on the way yet?

Chris

[RobertM]

Still have a long way to go with the H9, it really is a great little camera.  If I changed it for the QHY8 then I'd run into an illumination problem with the Celestron at F6.3.

How are you getting on with the FD72 and the 'Advanced Ritchey Chretien' (not sure whether I spelt that one right !)

[Fay]

Robert, what a fantastic image, you must be well pleased.

Fay

[Mike]

The H9 is a great camera. I rarely do darks with mine, though I should do flats as everything is covered in dust (though not quite as bad as the front cell on your Celestron Mark )

[RobertM]

I did sky flats with a white piece of old cotton sheet stretched across the front of the scope with a rubber band.  I think the calibration really needed darks too because of the gradient from a nearby streetlamp across the filter (yes shielded but light still gets through!).  Had also thought of cleaning the corrector on mine but I think it needs a lot of dust/stains/bird droppings to affect the image.

Hey Mike/Chris,  Isn't it about time one of you seasoned imagers posted something or have you given up for now

[Mike]

Robert, to be honest I find it hard to get the time to go out and do stuff apart from on Friday or Saturday nights (if i'm not already out doing something social on those nights) and on the nights I have been free most of them have been cloudy. I do intend on getting out more often so watch this space.

[RobertM]

Mike, I can sympathise as I know the problem only too well.  I'd been travelling every two-three weeks for the last two years and with the social obligations in between it was very difficult to get anything in.  I have more time now so I'm finally starting to get things sorted out but it's a slow process.

Looking forward to your next posting so hope you manage to get out soon.

[Rocket Pooch]

Well I go to wales 3 days a week, how do I feel.  But don't worry, I will get imaging again soon

[MarkS]

Wales has some very dark skies ...

[Fay]

Robert, you could do a short talk on members evening & go thru your processing stages etc of M51

[RobertM]

Hi Fay,

I'm not sure I feel confident enough for that yet.  I'd be more than happy to once I understand exactly what I'm doing however at the moment it's very hit and miss ... twiddle this adjust that etc so I'm a little less than confident of the steps to reach the result.  One of the Imaging evenings would be different where some of the experienced imagers can provide a critique of my crude techniques also I wouldn't mind showing anyone who want's to come around.