Preparing for my first attempt at DSO...

[ryandsimmons]

Equipment:

Celestron C8

CG5 Mount

Canon EOS 1000d camera.

Equipment missing: Light pollution filter for EOS 1000d, laptop to control EOS, Bulb remote.

Target: Whirlpool Galaxy.

Location: Back garden, medium / medium low light pollution.

Well this is my plan anyway for the next clear night.  I have been having great fun with webcam astro pics, I find it very easy to get reasonable pictures with a rough video and a stack (getting GREAT pictures is a different matter obviously.) But I am finding this DSO stuff very tricky.  I don't suppose someone could just run through my steps and tell me if I am (planning) making any obvious errors. 

1) Set up scope as normal with eyepieces etc.  Double check balance etc.

2) 2 Star Align, then add 3 calibration stars on both sides of the sky.

3) Point at something bright, eg Jupiter, connect up camera with T-Ring etc, and focus. (i will need to use Live View as my laptop won't run EOS software.)

Then this is where I am unsure, because I am not sure about slewing to the target, finding it AND keeping camera focus...

So...

4a) Remove camera, insert eyepiece (leave focus on camera though, so should be blurred stars?) slew to Whirlpool Galaxy, do manual centering of the galaxy using fine slewing, then replace camera.

or

4b) Leave focused camera on scope, use GOTO to slew to the galaxy and pray that it is centre aligned already?

5) Camera settings are ISO 800, timer 10 seconds (to let vibration settle after pressing, I am aware that I need to get a bulb remote to avoid this), exposure 30 secs.  Output image as Raw, maximum resolution.

6) Take maybe 10 or 15 images.  Possible take some additional at shorter / longer exposure if people suggest.

7) Take some darks.

Does this all sound reasonable?  I do know that the camera has a function where you can take a series of pictures with gaps in between but I think you need the laptop for that?  The reason I am using 30 secs exposures is the lack of a bulb remote, the alternative is us the "Press bulb while having black cardboard over the end of the scope, wait for vibration to settle, remove carboard, expose, place cardboard over lens, press bulb to finish.

I am not looking for anything amazing, just something raw and rough to start with.

[red dwalf]

polar align then i use stellarium to slew to a star near to the object, center on object and then sync in stellarium then i`d use a bantinov mask and focus on the star, then when focused slew to m51 and take a image using iso 1600 or more of about 30 seconds, you should be able to see it m51, then if not centered you can slew the mount alittle and once done set iso to no more than 800 and fire away, are you guiding at all yet ? this will help alot with long sub lengths, if not your pa needs to be very good.

i also use astro photograpy tool to control the camera, this allows for a pause between shots, not sure about your method of using a bit of cardboard

[PhotoGav]

That looks as though it should work! Couple of things come to mind - at the beginning make sure your polar alignment is as accurate as you can manage, that will increase the chances of good tracking and decent stars in the exposure. When you balance the scope you should have it setup for imaging, ie with camera etc on it rather than the eyepiece, then go to eyepiece configuration for alignment etc.

What I used to do before connecting up a laptop was to get my target centred with the eyepiece and set a user defined object in the handset (I was using an HEQ5, so don't know what you can do on your mount / handset), then put the camera on, go to a star and focus, then slew back to the user defined object.

The other thing to do is just experiment once the camera is on by taking an exposure, check, move the mount a small amount in one direction, expose, check, repeat until happy. It can be a lengthy process, but if you can't see the object visually it's the only way to go!

Another thought - an illuminated reticle eyepiece helps greatly with good alignment. Also, definitely get yourself a cheap timer release cable on line. Use mirror lock on the camera, that will help with the vibration. The 10s timer just delays the shutter opening so won't help with waiting for vibrations to settle. Remember that you have to press the shutter release twice with mirror lock enabled, first to lift the mirror, second to open the shutter.

Good luck.

P.S. Even better - connect up the laptop to everything!!!

[ryandsimmons]

. When you balance the scope you should have it setup for imaging, ie with camera etc on it rather than the eyepiece, then go to eyepiece configuration for alignment etc.

Thank you!  That is the sort of pitfall that I would have totally missed.

A laptop etc is definitley on the cards, however I think my wife would divorce me.  She grudgingly allowed me the £1,000 to buy the scope and mount.  Then suddenly I needed another £150 for the camera which was DEFINITLEY the last spending.  Then I realised I needed a £20 T-Ring, then a £20 T-Adapter...  And so on.  I think I am up to £1,500 now just 2 months after buying the scope.  What makes it worse is I have a netbook that is perfect for webcam imaging etc, but can't use the EOS software as the screen is only 600 pixels high and the EOS needs 640.

[brantuk]

When I first put my 1000D on the back of a scope (with no PC hook up nor eye piece) I was left wondering how to align the finder to the main scope. Then someone told me I can just look through the camera view finder which is looking straight up the tube - did I feel daft or what lol.

Another tip - use the camera view finder cover to close it off once you're all set to take a snap. Otherwise you'll get light intrusion to the camera and a gradient in your images.

[Leveye]

Don't forget to use your "true" position with a compass when doing a basic alignment of the mount or it will be off by about 10-15 degrees..

[ryandsimmons]

Don't forget to use your "true" position with a compass when doing a basic alignment of the mount or it will be off by about 10-15 degrees..

Sorry, would you mind explaining this?

[hobsey]

Sorry, would you mind explaining this?

Basically I think what he is saying by this is, not to guess but get very accurate alignment north by using the compass.

[MartinB]

As has been said, nail the polar alignment.  If you start sloppy you'll stay sloppy.  Provided you've done a decent alignment have faith in the goto.  Don't restrict yourself to 15 pics.  It's tedious but more will really pay dividends.  Aim for a minimum of 30mins exposure time on something like M51.  Show us the result!

[Tinker1947]

Get a bahtinov mask to focus with, run through the Polar Align routine several times, slew to several stars around M81, use the last one to focus on and then slew to M81, take loads of images, a remote to give you 60 - 120 second exposures would be good......