Session Planning

[johnb]

Hi

Now i have the process sorted for DSO Imaging (well just about) I want to make sure the next time I go out i dont waste time on what to have a go at Ive done planning and woudl welcome opinion

I m using my Skywatcher Explorer 250 OTA & Skywatcher EQ6 Pro SynScan with my unmodded Sony A350 oh and im unguided.

Im planning to have a go at: M51 and M106 with about an hours worth of 40 second exposures on each target. After every 10 exposures (ie 400 secs) I will GOTO target again to ensure I stay on target. Does this sound like a sensible plan - really happy to corrected.

I assume I will be able to visually see these through the scope prior to imaging ?

Regards

John B

[FraserClarke]

After every 10 exposures (ie 400 secs) I will GOTO target again to ensure I stay on target.

I presume you're suggesting this because you're worried about the 'scope drifting off target?? In which case I don't think a GOTO will help you, because the 'scope will still think it is pointing at the target.

I'd suggest you just look at the first image that comes in, and identify some stars in the image (you should see some even in a forty second exposure). Then just look at how they move from image to image. If they are drifting off to one side of the image, slew the 'scope a little bit to put them back where you want them...

Very good idea to think about your procedures before you do it in the cold whilst dealing with sleep deprivation

[Psychobilly]

I dont think that repeating the "goto" won't improve anything...

The scope and mount will be tracking the object and as far as the "gubbins" is concerned looking at a fixed co-ord... Repeating the goto will just slew the scope off and then back to the same place...

If you alignments out then you would actually need to be "goto-ing" a slightly different place for each sub...

Peter...

[johnb]

thanks, I was thinking that as im unguided after x period of time it may be wise to perhaps goto a different target and then back.

Im not really sure what x is in seconds ?

Have I selected 2 reasonable targets for my session ? (I appreciate its a subjective question)

Regards

John B

[Psychobilly]

Honestly.... no

M106... if you have a look at this image

http://stargazerslounge.com/imaging-deep-sky/99363-m106.htm

And then at the exposure time etc... then an hours worth of 40s subs with a DSLR isn't going to give you much at all to work with... especially when you consider that the other image was with a sensitve mono CCD....

If your starting out with short unguided subs you would be better off looking at easier targets like globular or open clusters rather than faint galaxies or nebs...

Peter...

[johnb]

thanks for telling me like it is, its appreciated ( I know Im perhaps trying to run before I walk) I have a good view N,S, E and W so any suggestions are appreciated

Regards

John B

[Psychobilly]

Its just being enthusiatic...

If you havent already I would even take some "star" images these will give you an idea about as to how far out your alignment and subsequent tracking will be....

The best neb for short expsoures is M42 although getting a bit tricky but still worth a go...

How time limited are your viewing seesion let me know and i'll look up some targets for you...

Consider...

the following Messiers...

M42, 45, 36, 37, 38, and 44....

Peter...

[johnb]

Thanks so much, I think ive sorted Aglinment now (that took a while) so once setup I have a good couple of hours

Link here to my M42

http://stargazerslounge.com/imaging-deep-sky/100066-another-m42-but-my-first-semi-decent-one.html

which was some 4 mins in total - those issues are resloved.

Regards

John B

[Psychobilly]

Yep its a fine unguided M42 at a fairly long FL ... M42 is very bright and fainter targets really need longer exposures to give you something to stack...

I would use M51 as your "push" target.... see if you can get away with longer sub lengths... the core of M31 and M33 would be better but they have gone for a few months...

Peter...

[johnb]

Peter

Thats really appreciated M51 it is and I cant wait now I just need the you know what to clear and Im off

Thanks again

Regards

John B