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NightHawk · Joined: 05 Dec 2006 Posts: 38 Location: Dalgety Bay

Hi, Been a little while since I've been on here.

I gave up on astrophotography after a dark night in the garden getting annoyed with a tracking telescope, toucam webcam and laptop. Laughing

I recently spotted this:
Link

Was hoping this will work ok with my camera with the 52mm extending hood(not shown) that was supplied with the camera:

My existing lens is not detachable. But I've used a Fisheye lens recently that sits on the front of the lens for scenery shots, with excellent results.

My question is for anyone with astrophotography experience:

Should I be able to get ok star and moon pics(with manual camera controls) with this £25 ebay ring of plastic?

Or am I kidding myself? Rolling Eyes

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Meade ETX-80-AT-TC Achromatic Refractor

Cosmic · Joined: 12 Jun 2008 Posts: 190 Location: Dunfermline

Hi There,
Not too sure about using fish eye through scope eyepiece. I thought the lens had to be removed so the image could be brought to focus on the CCD chip inside. I could be wrong.
However there are more experienced members than I in this department.
Try Andy or Bob .

regards

Cosmic
_________________
Meade LX90 UHTC 8" SCT
Celestron Nexstar 5SE SCT
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15x70 Astro Binoculars 10x50 Binoculars
When I was a child I had a dream......now I own a telescope ....it's no longer a dream.

astrogeorge · Joined: 25 Oct 2007 Posts: 77 Location: Kirkcaldy

HI nighthawk,
With the adapter you would get great images of the moon and planets, as for deep sky i'm not sure but you could always try it.

George
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Celestron C100ED-R, Meade LX200 10" & Series 5000 80mm Apo, Coronado PST
EQ6 Pro with GPS
Meade Series 4000 Eyepieces & 2x Apo Barlow
Tele Vue 4x & 5x Power Mate
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Cosmic · Joined: 12 Jun 2008 Posts: 190 Location: Dunfermline

Hi George

Question. Can you use one of the digital SLR's with the lens still on camera?
I mean by just pointing it down the eyepiece? does it work or does the lens have to
unscrewed and connected to the scope eyepiece socket with an adapter?
I think Nighthawk said his lens can't be unscrewed.

Sorry if I'm wrong.

Cosmic
_________________
Meade LX90 UHTC 8" SCT
Celestron Nexstar 5SE SCT
Mintron MTV-12V6HC-EX ccd video cam
15x70 Astro Binoculars 10x50 Binoculars
When I was a child I had a dream......now I own a telescope ....it's no longer a dream.

astrogeorge · Joined: 25 Oct 2007 Posts: 77 Location: Kirkcaldy

Yes cosmic you can take images with either a hand held or digital slr with the lens just by pointing the camera at the eyepiece. There are also brackets avalable that will hold the camera in place, most of the images i have posted on the forum where taken with a samsung compact digital. I will bring the bracket to the next meeting to show you.
_________________
Celestron C100ED-R, Meade LX200 10" & Series 5000 80mm Apo, Coronado PST
EQ6 Pro with GPS
Meade Series 4000 Eyepieces & 2x Apo Barlow
Tele Vue 4x & 5x Power Mate
Meade DSI Colour & DSI II Pro, Image Source DBK 21, Canon Eos 400D

pbholmes · Joined: 15 Nov 2006 Posts: 167 Location: Dalgety Bay

Hi Nighthawk,

I have a camera of a similar size and shape to the one you show, and like yours, the lens is not detachable. I've tried to use it through my telescope with disappointing results.

I did my tests just by holding the camera up to the telescope eyepiece, without any hardware to hold it in place. While this is inconvenient for serious photography, it's fine as a way of finding out what the results are likely to be like. Its easiest to do during the day, pointing at a landscape.

The result I got was that it would focus OK, but only the very centre of the image was visible. Around that, it got darker, and most of the shot was black. I've read that this effect is called "vignetting". As a rough approximation, it happens when the camera lens is bigger than the eyepiece lens. It can also happen when the field of view of the camera is wider than the apparent field of view of the eyepiece.

My scope has a 1.25" focuser. If your scope has a 2" focuser, and larger eyepieces, your results may be better than mine. Also, using a smaller camera, such as a mobile phone camera, may help. Unfortunately, small cameras capture less light, and often allow only short exposure times, so it's hard to capture anything dim.

My recommendation is to try holding the camera to the eyepiece by hand, during the day, to see what the vignetting is like. If bad, the adapter ring is unlikely to improve it.

You can also get webcam adapters, and although the resolution is much less, at least the image fills the frame. I have one of these, and you would be welcome to borrow it if you're thinking of getting one.

P.

bwh · Joined: 06 Feb 2007 Posts: 146 Location: Dalgety Bay

Nighthawk,

answer looks like possible, but may be other ways.

I have a Pentax attachment (T-ring ? ) - which replaces lens - and this has three grub screws holding central element which supplies thread.

I then have small adapter which screws into the pentax central thread and is sized to 1.5 inch eyepiece. 2 inch tube length after thread.

I then have third part which is 6 inch tube - which seems to all camera to sit above an eyepice.

Maybe all you need is the 2nd part which allows camera to be used instead of eyepiece. But does not seem the part you mention is this....

Happy to send these three elements to the next meeting so people can analyise and borrow for a while.

I think there are two modes to use your camera:

a) in place of eyepiece - your camera is the eyepeice.
b) in combination with an eyepiece.

I do have a 55m camera too - but still fighting the toucam/DSI/clouds/tracking issues.

b
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bwh

Meade 8inch (228mm) LX5 Smidt-Cassegrain fl=2000
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NightHawk · Joined: 05 Dec 2006 Posts: 38 Location: Dalgety Bay

Thank you for your comments and suggestions.