Astronomical 'First Light' for my Canon 1000D - What am I doing wrong?

[Thalestris24]

Hi

It's still a bit out of focus but at least you have an image now! If you can focus on more distant terrestrial objects that would be useful. You will need to rack in a bit in order to focus on objects at infinity but hopefully you should be able to do that.

Good luck with the moon next time!

Louise

[happy-kat]

The image of the trees is not as clear as I would expect.

I think we need to step backwards and first we need to identify can your telescope and your camera acheive focus.

I thought I had read somewhere about this.

Not all cameras and all telescopes can reach focus because either there is not enough in or out focus distance available on the focuser unit on the telescope.

1 - are you now attaching your camera (with no lens on) direct into your telescope focuser tube (where you would normally put an eyepeice but you do not have an eyepeice in it now)?

2 - put you camera M mode and them live view and aim your telescope the furthest away object in day light (like really far away) and try to focus.

3 - are you running out of moving the focus tube inwards or outwards in trying to make the live view image look sharp?

Your telescope has a fixed length and a set f number which is the focal length divided by the apperature, so 900/130= an f nunber of f6.9. this means in manual mode on your camera all you can change is the shutter speed and ISO because the f stop is set by the telescope which is acting as a big lens.

[Arcturian]

The image of the trees is not as clear as I would expect.

I think we need to step backwards and first we need to identify can your telescope and your camera acheive focus.

I thought I had read somewhere about this.

Not all cameras and all telescopes can reach focus because either there is not enough in or out focus distance available on the focuser unit on the telescope.

1 - are you now attaching your camera (with no lens on) direct into your telescope focuser tube (where you would normally put an eyepeice but you do not have an eyepeice in it now)?

Correct. Forgot to say earlier that with the current set up there's no way to mount a lens inbetween the camera and the telescope, the lens sticks out too far of the T-Ring to be able to fit the camera on

[happy-kat]

I did a search for your telescope being used with a camera attached and I did find posts suggesting focus issues as there was not enough inward travel in order to make the image focused.
But first you need to establish that this is the case for you.
Reading the thread again I am not convinced you have the following
camera (no lens) > t ring > t adaptor > telescope
it might be that you can fit the t ring straight to the end of your focus tube, but I like using a t adaptor.

If you have a barlow then it might help gain focus

camera (no lens > t ring > t adaptor > barlow > telescope

[Thalestris24]

This might be useful:

http://www.alananna.co.uk/blog/2012/using-an-slr-with-a-skywatcher-explorer-130m-telescope/

[Arcturian]

I did a search for your telescope being used with a camera attached and I did find posts suggesting focus issues as there was not enough inward travel in order to make the image focused.

But first you need to establish that this is the case for you.

Reading the thread again I am not convinced you have the following

camera (no lens) > t ring > t adaptor > telescope

it might be that you can fit the t ring straight to the end of your focus tube, but I like using a t adaptor.

If you have a barlow then it might help gain focus

camera (no lens > t ring > t adaptor > barlow > telescope

Alright up until now i didn't realize people were saying t-ring and t adapter were a different thing. I have a black ring that screws onto the eyepiece & the camera lens mount on either side. What's the difference in these 2 types of T adapter?

[Thalestris24]

Alright up until now i didn't realize people were saying t-ring and t adapter were a different thing. I have a black ring that screws onto the eyepiece & the camera lens mount on either side. What's the difference in these 2 types of T adapter?

This page shows a t-adapter and t-ring below:

http://www.firstlightoptics.com/adaptors/flo-125-inch-t-mount-camera-adapter.html

The t-ring is camera specific

[Cornelius Varley]

The pictures definitely show a focusing issue. Most visual reflectors don't have sufficient inwards focuser travel to allow the camera to reach the point of focus. To get around this problem a barlow lens is used which will move the point of focus outwards allowing the camera to be place at the point of focus. This video explains how and why

Adding the barlow to the image path is also a good thing because you will be able to take more detailed images of the moon rather than squeeze the full disc onto the sensor. This image was taken at the same focal length (1800mm) to give you an impression of what can be achieved

link to the fullsized image on astrobin

http://www.astrobin.com/full/8733/0/

[cockney]

nature and astronomy on youtube do a good video on attaching dslr to a telecope http://www.youtube.com/watch?v=cYTmsfpL0M4  if you do these steps you shouldn't go wrong. if you still get images like in your post then i think something else maybe wrong.

[Arcturian]

This page shows a t-adapter and t-ring below:

http://www.firstlightoptics.com/adaptors/flo-125-inch-t-mount-camera-adapter.html

The t-ring is camera specific

Thalestris so I have the T-ring but not the T Adapter?

Cornelius the T ring leaves no room for a lens to be fitted, all lenses (but barlow the most so) stick out past the T-ring, making me unable to mount the camera. Is the item Thalestris posted above the key to that problem?

[Arcturian]

nature and astronomy on youtube do a good video on attaching dslr to a telecope http://www.youtube.com/watch?v=cYTmsfpL0M4  if you do these steps you shouldn't go wrong. if you still get images like in your post then i think something else maybe wrong.

Am watching the video now pal. Thanks

[cockney]

oh i posted my post and then cornelius varly post popped up when the page refreshed. but it wasn't there when i read the thread hhmmmm.

[Cornelius Varley]

Thalestris so I have the T-ring but not the T Adapter?

Cornelius the T ring leaves no room for a lens to be fitted, all lenses (but barlow the most so) stick out past the T-ring, making me unable to mount the camera. Is the item Thalestris posted above the key to that problem?

You  won't need a lens. The telescope acts as a large telephoto lens and this is all you will need. Attach the camera body to the barlow lens using the t ring and t adapter and pop these into the focuser drawer tube.

[happy-kat]

There is lots of helpful posts on this thread, take your time and go through them and watch the video.

[Arcturian]

You  won't need a lens. The telescope acts as a large telephoto lens and this is all you will need. Attach the camera body to the barlow lens using the t ring and t adapter and pop these into the focuser drawer tube.

With a barlow lens wont that seriously restrict what i can image, because there will be 2x as much zoom, isn't that a pretty significant difference? So doing this would decrease the blur? And theres really nothing I can do now to even get a mildly detailed image of the moon with this scope? That doesnt seem right

[Cornelius Varley]

The barlow is required so that the camera will reach focus, without it you just get a blurred unfocused image. The youtube video in my earlier post explains why the barlow is needed. 

[Thalestris24]

With a barlow lens wont that seriously restrict what i can image, because there will be 2x as much zoom, isn't that a pretty significant difference? So doing this would decrease the blur? And theres really nothing I can do now to even get a mildly detailed image of the moon with this scope? That doesnt seem right

Hi

Yeah, a x2 Barlow will double your focal length and so narrow the field of view. However, as I understand it, using one is a simple way of enabling your scope to achieve focus with a dslr if you can't otherwise focus. Did you watch the video that was posted and read the info at the link I posted previously? Some Newtonian scopes, such as the 130pds/150pds etc. are specifically designed to accommodate a dslr at prime focus but others don't guarantee it.

Louise

[Cornelius Varley]

The barlow lens will reduce the fov but this is the most practical solution to get a camera to focus with a newtonian telescope. 

[happy-kat]

The primary mirror is too far away to reach focus from my searching of similar posts of your specific telescope.

So you either use a barlow to move the focus point nearer for the camera.

Or

You take your scope apart and move the primary mirror closer.

Or

You try a web cam that might focus straight away with no barlow.