Taking more data at a later date.

[Penfold]

How do you do this?

As in getting the camera in the same position as your previous attempts but on different nights.

[carastro]

It's a good idea to make some sort of marking on you scope/camera to make sure you always put it in the same position.

Then try to get the target central on the first batch. Have a copy available of your original image to go by and try to slew it to the right place.

If you have a DSLR APT software (costs about £11) i.e. Astro-phoptography Tools does an image mask facility where you can import a previous image and line up the new live view with it.

As for stacking, I have done this a few times now, just bung it all into DSS and it will line it up for you, but remember you need to use separate darks and flats for each night's imaging. There is a tab at the bottom where you can do this separately, or stack each night separately and then re-stack the stacked tiffs. If there is any rotation or misallignment, it will straighten it for you and you'll just need to trim the edges.

Hope this makes sense.

There might be an even better way than this that some-one might come up with.

Carole

[Sparrow]

That sounds pretty good Carole - my method is a bit more haphazard - I have a look at previous subs for the target and make a mental note, and then get my framing as near as possible to the previous subs. It helps that I don't remove the camera between sessions so that it is in exactly the same orientation.

p.s. My wife woul be glad to see that you spell your name the proper way as well with an E at the end

[ollypenrice]

I was going to say, leave the camera in if you can and don't rotate the scope in its rings, then you can use the same flats as well as save time orietating the image.

I use Registar to check one shot against another but it would be an expensive solution if that is all you used it for.

Easier for me because I have square chips, but I try to keep the chip lined up along RA and Dec, which makes coming back to old data easier. Of course sometimes the target won't allow it.

Olly

[Ibbo!]

I mark up with tippex

It comes off when you need it to(also when you don't as well if you catch it)

Steve

[carastro]

I mark up with tippex

Yes that's what I do.

Carole

[Penfold]

Thanks for the info all, looks like I need to get some tipex then As well as something to blow all this damn mist away.

I was expecting a much more complicated procedure... As usual simple is best.

[ollypenrice]

I mark up with tippex

It comes off when you need it to(also when you don't as well if you catch it)

Steve

Brilliant idea! Thanks for that one.

Olly

Edit, Monique is picking me up some Tippex this morning. It exists in France as well. Phew.