Canon 450D

mswhin63 (Malcolm) · #1 07-01-2010, 12:49 AM

Sorry got the wrong forum post.

Hi All, just got my 450D yesterday

so far brilliant camera, been playing around taking snapshot then deleting them.

Anyway my next task is basic imaging similar to what I have done with the webcam. I am looking at the right adaptors to make a package.

So far - https://www.bintelshop.com.au/Product.aspx?ID=7403 along with https://www.bintelshop.com.au/Product.aspx?ID=5551 will be all I need for prime focus, but as with my past experience with prime focus I run out of focus travel on most webcams.

I was considering another alternative - http://www.myastroshop.com.au/produc...sp?id=MAS-052H and http://www.myastroshop.com.au/produc...sp?id=MAS-052D to shorten the focal point of the DOB but the picture does not allow me to determin whether it will replace the 2" Skywater DOB adaptor shown in the picture attached. The Lumicom 2" adaptor looks like it has a wedge but i just can't be totally sure and not sure if it can replace it anyway.

Can anyone verify it for me, as I have to work tomorrow and won't have enough time to call.

Thanx

Tandum (Robin) · #2 07-01-2010, 02:01 AM

Malcom,
You haven't said what scope you want to plug this into but looking at that extension in the image I'd guess an 8" newt.

After checking your links and looking around it appears they are trying to increase profits and are splitting the camera adapter from the nosepiece and selling them seperately.

I've attached pictures of my old canon adapter and you can see it splits into many pieces. When I was using it I unscrewed the tiny screws around the bottom part and removed that insert from the bottom section so the top tube screwed straight in. I was lucky that there was a thread inside to suit.

I believe this one is the best these days.

mswhin63 (Malcolm) · #3 07-01-2010, 02:10 AM

Sorry the scope is a Skywatcher collapsable DOB, the picture is the 2" adaptor from the scope. I really want to shorten that adaptor (I could get a hacksaw) and wasn't sure if the Lumicon from Myastro Shop had the same wedge shape as my adaptor. Doing this will acheive prime focus better for the DOB but 1" which does not have a lot of travel left with the webcam I am using.

Tandum (Robin) · #4 07-01-2010, 02:15 AM

You don't need that lip/wedge shape at all. Achieving focus is another matter.

You can't track stars automagically with a dob, so you won't be able to take photos either.

They get those nice pics by following a star in a second telescope.

But both scopes are linked so they get a nice deep space image from the imaging scope.

Can't do that with a dob. You'll need an eq mount to follow stars.

mswhin63 (Malcolm) · #5 07-01-2010, 11:24 AM

Quote:

Originally Posted by Tandum

You don't need that lip/wedge shape at all. Achieving focus is another matter.

You can't track stars automagically with a dob, so you won't be able to take photos either.

They get those nice pics by following a star in a second telescope.

But both scopes are linked so they get a nice deep space image from the imaging scope.

Can't do that with a dob. You'll need an eq mount to follow stars.

Not sure if this is the advise that I wanted, the low profile adaptor if it fits will also help with my webcam images of the moon and planets. I also expect the DSLR will help with the moon as well as I run out of focus travel just with the webcam insert prime focus.

http://picasaweb.google.com/mswhin63 is what I have done already in the DOB, I am also planning to track the DOB with either a wedge or Bartel.

Tandum (Robin) · #6 07-01-2010, 11:55 AM

Malcolm, you might want to ask someone who owns a collapsable dob if they can get focus with a DSLR and how they did it. I seem to remember the sensor in a 450D is something like 44mm in while your webcam would be closer to 10mm in.

tlgerdes (Trevor) · #7 07-01-2010, 12:24 PM

Is it in-focus or out-focus you run out of? DSLR will probably focus at different point to your webcam due to the position of the sensor.

mswhin63 (Malcolm) · #8 07-01-2010, 05:04 PM

Quote:

Originally Posted by tlgerdes

Is it in-focus or out-focus you run out of? DSLR will probably focus at different point to your webcam due to the position of the sensor.

Car broke down today, so I managed to phone and find out, turns out the DOB 1.5" adaptor can be unscrewed to expose a T thread (learn something new everyday). That will short the focal legth for the DSLR by 1/2 to 1". With that in mind I will try and look for a solution for the webcam now.

So it look like I only need to purchace a T to EOS adaptor only.

Thanks for the assistance all.

Garyh · #9 08-01-2010, 04:44 PM

Hi Malcom,
If you don`t have enough infocus you really only have two choices.
Get a low profile focuser and replace the standard one or you can push the primary mirror up with longer screws. Depends how far off you are at achieving focus. You can get away with 10mm or so by doing this, if not you need to get the low profile focuser. The thin T-thread adaptor will make no difference with the focal point only if you have a OAG or a corrector that stops the insertion of a longer 2" barrel.
Even with a dob you should get some nice lunar pics at prime focus but you will be limited to a few seconds at best before the stars elongate.
Anything longer you will need a EQ mount.
cheers Gary