Jump to content

Banner.jpg.b83b14cd4142fe10848741bb2a14c66b.jpg

Prime focus stuff

thing

By thing
in Imaging - Discussion

Recommended Posts

thing

thing

Posted
Posted

Received the adapters for my camera for my birthday and managed to get 15 minutes or so with it before the clouds rolled in this evening. Three things I noticed:-

1. I can't focus it, there's not enough forward travel on the focuser.

2. I can focus it with a Barlow (Ultima x2) but I don't want to do close up shots.

3. The shots I took were 'orrible! Very poor compared with piggybacking the camera with a 300 mil lens.

Anybody any thoughts?

Link to comment
Share on other sites
brendant

brendant

Posted
Posted

Getting a camera to focus on a Newt is usually problematic, can you maybe give a better idea of what camera you are trying to mount and maybe a picture of the camera mounted and the bits you are using.

I had trouble at first with my 6" Newt (TAL-2) and 400D DSLR which required some mods to get it to focus as I had the same problem you are experiencing, I'm sure it can be sorted and there must be others on here with the same scope. As a rule use the least amount of connectors possible.

Brendan

Link to comment
Share on other sites
Andrew*

Andrew*

Posted
Posted

I could never get prime focus focus (can I say that?) with my SLR in the standard focuser on the newt. I now have a low profile focuser and I assume (haven't tried it yet) that it will reach focus. If you can manage it, a very very worthwhile upgrade from the standard R&P focuser is a dual speed, low profile crayford. If you can stretch all the way - a moonlite 8).

Andrew

Link to comment
Share on other sites
brendant

brendant

Posted
Posted

Had a quick look through the Celestron Manual for you scope and found the following text, don't know if it applies or not :-

Short Exposure Prime Focus Photography

Short exposure prime focus photography is the best way to begin recording celestial objects. It is done with

the camera attached to the telescope without an eyepiece or camera lens in place. To attach your camera,

you need the T-adapter and a T-Ring for your specific camera (i.e., Minolta, Nikon, Pentax, etc.). The

C8-N and C10-N focuser have a built-in T-adapter and are ready to accept a 35mm camera body. The TRing

replaces the 35mm SLR camera’s normal lens. Prime focus photography allows you to capture the

entire solar disk (if using the proper filter) as well as the entire lunar disk. To attach your camera to your

telescope:

1 Remove the eyepiece from the 1 1/4" eyepiece holder.

2 Unthread the 1 1/4" eyepiece holder from the focuser assembly. This will expose the male thread of the builtin

T-adapter.

3 Thread the T-ring onto the exposed T-adapter threads.

4 Mount your camera body onto the T-Ring the same as you would any other lens.

If this is so you can connect a T-Adaptor ring directly to the focuser, this should then enable focus to be reached without having to resort to a new focuser with a bit of luck.

Brendan

Link to comment
Share on other sites
thing

thing

Posted
  • Author
Posted

Had a quick look through the Celestron Manual for you scope and found the following text, don't know if it applies or not :-

Short Exposure Prime Focus Photography

Short exposure prime focus photography is the best way to begin recording celestial objects. It is done with

the camera attached to the telescope without an eyepiece or camera lens in place. To attach your camera,

you need the T-adapter and a T-Ring for your specific camera (i.e., Minolta, Nikon, Pentax, etc.). The

C8-N and C10-N focuser have a built-in T-adapter and are ready to accept a 35mm camera body. The TRing

replaces the 35mm SLR camera’s normal lens. Prime focus photography allows you to capture the

entire solar disk (if using the proper filter) as well as the entire lunar disk. To attach your camera to your

telescope:

1 Remove the eyepiece from the 1 1/4" eyepiece holder.

2 Unthread the 1 1/4" eyepiece holder from the focuser assembly. This will expose the male thread of the builtin

T-adapter.

3 Thread the T-ring onto the exposed T-adapter threads.

4 Mount your camera body onto the T-Ring the same as you would any other lens.

If this is so you can connect a T-Adaptor ring directly to the focuser, this should then enable focus to be reached without having to resort to a new focuser with a bit of luck.

Brendan

Thanks Brendan, I tried that but the T-ring for my camera doesn't even have a thread on it. I'd read that bit of info in my manual but it's a nonsense really, I can't see how anything could fit to it (the scope focusser that is). There is no 'male thread on a built in T adapter, ' and the 1 1/2 inch adapter doesn't unscrew, it's just held in with two grub screws.

Link to comment
Share on other sites
thing

thing

Posted
  • Author
Posted

:wink::) :) :) Eureka! The bit that comes off the adapter was screwed down really tightly, I didn't know that that bit came off. In desperation i just tried turning everything that came off the focuser with superhuman strength (well.......) and the [removed word] gave way. I've just had the scope out taking pics of local aerials and trees etc and it works a treat. Magnifies far more than I thought though, probably about x35 or thereabouts. No wide field shots then...........

Thanks for all the advice anyway guys.

Here's an aerial pic, probably about 200 yards as the crow flies.

4253_normal.jpeg

(click to enlarge)

Link to comment
Share on other sites
  • 1 month later...
trevboyd

trevboyd

Posted
Posted

I had no probs fitting my D50 to my C8-N with a T-ring, everything fits together easily just as the manual says. No issues with focusing either.

410ac080f5fcc05c2dcec925cc09acf5.jpg

Hi all

I have a related problem with my 350d and C8-N. I can attach it as in your pic, BG and all works fine. Only problem is that I can't fit a LP filter in the light path anywhere, and without it, I get bright red images (****** south east of England!) - have you tried? I have a 1.25" filter, but having to get a 2" one wouldn't be a problem.

Trev

Link to comment
Share on other sites
Kaptain Klevtsov

Kaptain Klevtsov

Posted
Posted

Trev, have a word with Bern at Modern Astronomy, he recently got hold of some LP filters that live inside the Canon cameras. Should do the trick.

Otherwise get a 2" T mount adapter, saw off the 2" filter thread end and glue just the threaded end inside the 'scope adapter. Works for me.

Kaptain Klevtsov

Link to comment
Share on other sites
trevboyd

trevboyd

Posted
Posted

Trev, have a word with Bern at Modern Astronomy, he recently got hold of some LP filters that live inside the Canon cameras. Should do the trick.

Otherwise get a 2" T mount adapter, saw off the 2" filter thread end and glue just the threaded end inside the 'scope adapter. Works for me.

Kaptain Klevtsov

Nice idea, KK! Like it! :(

Trev

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.