M81 with dust bunnies! and now without!

[Rocket Pooch]

I also need to clean my filters.

VC200L 11x5 minute images, CLS Filter HX916 Binned 2x2.

[JohnP]

Hi Chris,

First image in a while & very nice it is to. I think M81 is quite difficult to capture well & you have done a good job - Shame about the dust though... Is it possible to layer images to stop the core from burning out...? I like the scale of this- it fits nicely on the chip - I will give it a try with the SC3 sometime soon...

Cheers,  John

[Fay]

Really nice, Chris. It is a nice galaxy for a closeup.

Fay

[Rocket Pooch]

ok you will see from above John persuaded me to go back out in the garden today and take some flat frames and subtract them from the images the other night, it looks better now, shame it was not in focus nor did it have enough subs, maybe I'll have another go soon.

Also to create the flat on the Vixen I bough some clear white plastic from the Sign shop in new eltham and just put it on top of the scope in the daylight, simple, not light box needed.

[JohnP]

Cool... Much improved - The flat really worked... Had you left the camera etc. in the scope (did you have to make sure it was the correct orientation etc.) I'm impressed - Image looks excellent now - You should do some RGB next time you are out.

Cheers,  John.

PS - I need to borrow some of your white plastic & get you to show me how to do the flats....

[Fay]

Chris, that is really good. Although I could not see the dust bunnies on the original, not like the ones on my M51 which were really obvious.

I must get some clear white plastic!

Fay

[JohnP]

Hi Fay,

Have you checked the calibration of your monitor - the dust bunny  was so obvious on my laptop with the original....

Cheers,  John

[Fay]

John, I dare not touch my monitor! I was doing something with it a month ago & ever since all the writing has been in German & I can't get the English back!!!


Fay

[Fay]

Chris,
I am also interested in if you had to have the same settings for the flat frame & how many did you take. Could you see thru the plastic?
Did you hold it right up against the front of the scope?

Fay

[Whitters]

Hi Fay,
The white plastic is usually called milk bottle white, it is opaque and you will want to check that there are no obvious blemishes in it.

Chris, where is the sign shop, I had to get mine from Avicraft, but I was looking for some better stuff.

[Whitters]

That flat has sorted out the vignetting in the field too, a very nice image, lovely round stars.

[Rocket Pooch]

hi Paul and Fay

the shop is on avery hill road new eltham, you go past the railway station on your left through the lights, over the mini rounder bout and then the shop is on the right, its used to be a kebab shop i think, anyway you won't miss it, its on the corner, i got a 14x14" off cut for a fiver.

fay the flats do not need to be exposed as much as the subs they should however be approx 1/10 - 1/3 the well depth of your ccd, you have a 16bit ccd camera in the starlight express, therefore you should have 6-20k adu's for the flats, these are then divided from the subs before stacking.  its all in the AIP4WIN book, still a good one to buy.

by the way, this was a test shot not one that's a keeper, its out of focus and if you look at it its grainy, I'm not being smug here its just that I know we can all do better, m81 is a very bright target, but it does not have a lot of contrast therefore i think it would not be easy to get a good image of it.

Chris

p.s. Fay have a look at this http://www.aavso.org/observing/programs/ccd/manual/3.shtml

[Fay]

THanks for that Chris, not sure I understand it, but thanks.

If you really want to be fedup ask John to show you the M81 he found, taken with Artemis 285 & 8" reflector from UK.
I think we should have a competition to see who can get the best, over a few months! Knowing our weather perhaps it should run for 2 years!!!!!

Fay

[Tony G]

Yeah!!
You lot go ahead and have a competition!!!!  
Take your images of M81
Just don't forget to give me a shout or message me when there is a competition with the moon or planet involved.

Tony G

[JohnP]

Tony,

We could always say Saturn, Jupiter or moon if you prefer...

Seriously though if you want to get into deep sky imaging then I'd say you couldn't go far wrong with the new Atik 16ic  http://www.perseu.pt/atik/product_atk16ic.php It has the exact same chip as my SC3 but with the added benefit of 16-bit data & peltier cooling & on top of all that it only costs £360. I'm seriously thinking about one as a potential step up from my SC3. Finances are tight at the moment though with loft conversions & the dreaded double glazing....

Anyway, lets see some Sat & Jup images from you - should be great with that 6-inch scope of yours....

John