Has anyone tried...

[pterodroma]

...imaging with a Nikon D300s and either a Skywatcher Explorer 150PDS or a WO ZS71ED?  If you have I'd love to hear your experiences and any hints and tips on technique that you can share.

cheers

[Herbig]

Hi, not used a Nikon or a Newtonian but have used a WO ZS66 with a Canon 40D. You will need a 'T' ring for the Nikon and a'T ' adaptor and almost certainly an extension piece of some sort to obtain focus, you could use a diagonal but it would be a little ungainly with a DSLR. You would also need a remote shutter release but you can use the self timer. Also some means of focusing the telescope like a Bahtinov mask for your ZS71. If the camera has live view switch this on and focus on a bright star for deep sky, it won't work on planets or the moon. If you don't have live view you will have to keep taking shots to check focus. Exposure depends on the object, obviously you need to set the camera to fully manual, start with 800 ISO and experiment with shutter speeds.

Hope this helps

[ronin]

Get a remote timer release from Amazon they enable you to take multiple exposures, you can set the exposure length and the period between - each as in 20 exposures of 20 seconds with a rest period of 10 seconds between. Usually made by Shoot about £25.

Also check the manual, for some cameras you can get the camera to take it's own dark and it subtracts this from the exposure. Some may have it set as a default others you may have to switch it on. If on then it will take a dark of equal length to the "normal" so in effect double the exposure time.

[pterodroma]

Thanks for the replies

I've got an IR remote, and if I need to get the camera body further away from the 'scope I've got a set of extension tubes that I can use for that.

'Take it's own dark'...I'm at the bottom of a steep learning curve and staring up

cheers

[wxsatuser]

Thanks for the replies

I've got an IR remote, and if I need to get the camera body further away from the 'scope I've got a set of extension tubes that I can use for that.

'Take it's own dark'...I'm at the bottom of a steep learning curve and staring up

cheers

Long exposure noise reduction, in your camera when set to on it takes a second pic with the shutter closed......

it's called a dark frame.......the dark is subtracted from the light frame to hopefully remove stuff like hot pixels and amp noise.

It works on any exposure over 8secs.

I suggest you buy Steve Richards book.....Making Every Photon Count

http://www.nightskyimages.co.uk/

click on my book

and for DSLR an excellent book on CD is A Guide to Astrophotography with DSLRs by Jerry Lodriguss, worth every penny.

http://www.astropix.com/GADC/ORDER.HTM

[Alien 13]

I can only comment on the WO ZS71 but as above you will need a 2" photo adapter and T adapter for the camera i would also recommend the WO field flattener 6 with that fitted you dont need the 2" extension.

The WO is quite heavy for its size, i reversed the foot to help with ballancing.

This is mine with the flattener fitted. Oh the RA eyepiece is usefull for framing sometimes.

[pterodroma]

wxsatuser - thanks for explaining dark frame

Alien 13 - thanks for the advice about field flattener

cheers

[edjrgibbs]

I think the IR remote will give you a max of 30s exposures. You'll need the shutter release to do longer in bulb mode. I've used mine with a 150p and Equinox 66 without a problem however I've found that darks are a necessity as noise is a problem . You can take darks with the cap on and integrate with free software called deep sky stacker. The ISO and shutter speed must be the same as the light frames.

[pterodroma]

edjrgibbs - thank you

I can run longer exposures using the in-built intervalometer on the D300S I think.  Will download deep sky stacker.  Can I take multiple light frames and just one dark frame, or do I need a separate dark frame for each light frame?

Really impressed with what a friendly helpful place SGL is I'm a member of a number of forums (alongside my growing interest in astrophotography, I'm a keen angler, cyclist, fishkeeper, birdwatcher - and most of the other forums I belong to are sometimes not a nice place to be).

cheers

[edjrgibbs]

Yep, I've found the same, really friendly place.

With darks I think it's a case of the more the better. Something to do with the signal to noise ratio. Someone with a better understanding will have to explain ;-)