All sorts of problems

[inksmithy]

I just read that sticky and I'm pretty sure I'm in the right place.

First up, I should note that I understand full well that I don't have the ideal imaging set up. In fact, I'm a really long way from an ideal imaging setup. At this stage, I'm not so much trying for full on imaging, I'm simply trying to get a better look at some of the things I see.

My setup:

Nikon Coolpix 5700. This isnt a DSLR, it's a high quality digital camera which looks like an SLR.

It does have a thread for a T-adapter, which I'm using to attach the camera to the telescope.

The telescope itself is a Celestron 127SLT Mak-Cas on an alt-az goto mount. Again, it isn't ideal, but at the moment I'm not looking to take exposures of any longer than a couple of seconds, if that long.

What I'm trying to do at the moment is get a white light image of the sun.

With that in mind, I have the camera attached directly to the telescope. I'm not sure whether it counts as afocal or prime focus, since the camera is attached to the telescope through a T adapter, but is using its own lens rather than aiming directly at the ccd.

The initial problem I faced had a lot to do with the fact that I dont know the camera very well.

Yeah, thats what the inside of a Celestron Mak Cas looks like I think. Pretty isn't it?

I managed to get the autofocus off, sort of - the next image isn't well focused at all but is illustrative - to find that I'm possibly facing more than just a problem with the camera.

Pretty plain there that I have some focus issues and I'm fairly sure that I'm going to need to upgrade to a lens removable DSLR, but have I hit a brick wall as far as images through this 127SLT goes?

My best guess is that the massive central obstruction which is so beautifully in focus in that first image is what is causing the huge shadow in the second image. Is imaging really impossible through a Mak-Cas?

Alan

[steppenwolf]

Unfortunately this won't work - the best result you can expect is a good shot of the inside of your telescope! Prime focus requires a camera with its lens removed - the telescope becomes the camera's lens.

As your camera is a 'bridge' camera (looks like a DSLR but does not have interchangeable lenses so it bridges the gap between a compact camera and a DSLR), the only way to image through your telescope is by afocal imaging. Here, you attach the camera to an eyepiece and the eyepiece projects the captured light into the fixed lens on your camera.

[Steve]

What I'm trying to do at the moment is get a white light image of the sun.

Please tell me you are using a solar filter!!!

IMPORTANT: Observing the sun without a purpose-made solar filter will cause irrepairable damage to your eye, possibly even blindness. Similarly, never photograph the sun through a telescope without a purpose-made solar filter.

[JohnnyD333]

Steppenwolf is right, I had a Nikon P90 which looks like a DSLR but is a glorified point and shoot. The lens is permanently attached to your camera and cannot be used for prime focus. You can take pictures of the image projected from an eyepiece (afocal), but by attaching it directly your camera will not reach focus. If you have a DSLR, you can remove the lens, attach it to your focuser, and your telescope becomes the lens. Otherwise, its like putting two camera lenses together and taking a picture which I imagine would be difficult.

[inksmithy]

Please tell me you are using a solar filter!!!

Steve, if you are the same Steve from FLO, yes, I'm using Baader Safety Film I bought from you guys a couple of weeks ago. See the blog link in my sig for details. It ain't pretty, but it works and as I proved today, strong winds won't blow it off the scope.

Alan

[inksmithy]

@steppenwolf and Johnny, I understand what you are saying about the bridge cameras.

I'm reading your book, steppenwolf, and its incredibly useful. As I say though, at the moment I'm just using the resources I have to hand -the adapter allowing me to connect the T adapter is one I got from the astroboot for a couple of quid.

Using the camera and a Barlows gives me results like the following - again, focus is an issue, but that central obstruction shadow seems much reduced.

I think the main message I'm getting though is that I will need a proper DSLR.

Bummer. Worth experimenting though I guess.

Saving for so many things now!

Thanks very much guys,

Alan

[Steve]

Steve, if you are the same Steve from FLO, yes, I'm using Baader Safety Film I bought from you guys a couple of weeks ago. See the blog link in my sig for details. It ain't pretty, but it works and as I proved today, strong winds won't blow it off the scope.

That is good to hear Alan

I didn't see it mentioned in your opening post so was alarmed.

[JohnnyD333]

Don't be sad. I love my P90, and I love having money in my bank account, but buying a DSLR has been one of the best decisions Ive made. If you like photography you will not be dissapointed.

[inksmithy]

Don't be sad. I love my P90, and I love having money in my bank account, but buying a DSLR has been one of the best decisions Ive made. If you like photography you will not be dissapointed.

Johnny, not sad so much as stretched! There are so many directions to go in astronomy, its hard to know where to go first.

Alan

[JohnnyD333]

Stretched is the perfect term for this. I originally bought a telescope for observing. After a couple months I became obsessed with getting what I saw in the EP on camera. I purchased an EQ mount, almost a $1000, and today I placed an order for an autoguider around $400. I love doing AP but damn I still have a long way to go.