Deep Sky (don't laugh :) )

peterako · 28-02-2011 4:13pm #1

So, with the lack of planets at decent hours and altitudes I have started to dabble in DSLR pics of deep sky.

Starting with Orion and the Great Nebula in Orion.

No layering yet, and have found focusing even trickier than with the Webcam!

1. Just a DSR on a Tripod, manual setting, 30s exposure, no tracking:

2. Nebula (25s exposure, tracking, early days!)

Clear skies,
Peter

Plug · 28-02-2011 5:39pm

Its a pity you can't see colour like this with the naked eye:(

peterako · 28-02-2011 6:50pm

Yep, if only we were squids or something like that

But...I CAN see a lot of the cloud like detail with the naked eye through the scope here so I must be doing something to limit the camera shots as I should be getting more.

Maybe it's focus, or my mount is not aligned well enough of up to the job.

But it's another skill I'm more than willing to try and learn

mickger844posts · 28-02-2011 6:51pm

Good job, very nice shots.

Riamfada · 28-02-2011 10:10pm

What lens are you using?

MoonDancer · 28-02-2011 10:13pm

Thats great, thanks for sharing 8)

peterako · 01-03-2011 9:36am

Riamfada wrote: »

What lens are you using?

Hi Riamfada,

In the first shot a less than perfect Canon EF-S 28-105mm which I picked up from ebay for...£21! Manual focus.

The second is the camera connected to the 'scope. No camera lens but I did use a 2.5x Revelation (GSO) Barlow to reduce the focal length as I do not have enough travel on my focusser (inwards) to get focus.

Take care,
Peter

Popoutman · 01-03-2011 12:56pm

The 2.5x barlow will give you a much slower f/ratio amd a much longer focal length. This is the main reason why you don't have as much nebulosity as you may expect.
How much in-focus are you missing to get the camera focused? What scope is it?

dlofnep · 01-03-2011 1:04pm

Nice shot of M42

Good work.

peterako · 01-03-2011 1:18pm

Popoutman wrote: »

The 2.5x barlow will give you a much slower f/ratio amd a much longer focal length. This is the main reason why you don't have as much nebulosity as you may expect.
How much in-focus are you missing to get the camera focused? What scope is it?

I'm about 1cm short on in focus

I'm using a Celestron G8N (8" reflector/hybrid....there's a lense in between the two mirrors :eek: ).

I've already replaced the rack and pinnion focusser with a Crayford which has given me 3+cm more in focus than the stock focusser.

I MAY be able to salvage some more in focus by changing or adjusting my camera T2 mount or using just the 2" part of the focusser.

Many thanks for the tips/observations.

It's very new to me and I'm sure it can only get better

Peter

Popoutman · 01-03-2011 2:05pm

You may be able to get the necessary focus distance if there is a bit of leeway in the collimation bolts for the primary mirror, to push the primary further up the tube.
Some of the meade and celestron focusers have screw threads that allow the direct mounting of the camera mount to the focuser, you may be able to get that this way.
That scope has a spherical main mirror and a corrector lens assembly and it is quite sensitive to collimation.
Good luck with it.

peterako · 01-03-2011 4:19pm

I think I have the Collimation pretty good

One day (sigh...dream) I'll be able to get a proper Newtonian and then it'll all be so simple

I don't fancy moving the mirror forwards though. Not a lot of thread available back or forwards unfortunately in any case.

If I keep up the DSLR stuff and deep space I'll find a workaround

Many thanks for the suggestions,
Peter

Deep Sky (don't laugh :) )

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