My first ever SBIG shot

[[1ponders] (Paul)]

I know the one, but that's Ok, when I've got autoguiding going like it is tonight, I can wait.

(I'm working on a few images at the moment. I've just trying to get the feel of it. I think the FR is causing some probs. I'm just about to swap the FR over with the WO one and see if that makes a difference.)

[[1ponders] (Paul)]

The left hand image is using the Meade Focal Reducer and the right hand one is the native f10 of the SCT. Both taken after collimating.

[ballaratdragons (Ken)]

How did you go, Paul?

We posted at the same time.

I'm waiting for the pics . . . ahhh, here they come!

EDIT: Eek! What happened?

[[1ponders] (Paul)]

I'm just about to pack it in Ken. I was having problems focusing again tonight so about an half an hour ago I though I'd check to see how far out my collimation was. Well I go a bit of a surprise. As you can see from the image above the FR I have is not worth a pinch of the proverbial. Absolutely disgusted in the quality of it, considering how much they are worth. No wonder I couldn't get a decent shot with it when I had it attached to the ED80.

[ballaratdragons (Ken)]

Hmmmm, damn frustrating when stuff doesn't deliver what it's suppose to.

The one with the FR is almost invisible! That's not right.

[[1ponders] (Paul)]

That's just the exposure length I used as well as a different star. I'm more concerned with the football shape of it. The thing is, I've been using this FR for the past 2 years without realising how bad it was. If I had just bought it, it would be on the first bus back to the shop.

When I first started tonight I thought it might have been my autoguiding letting me down but its been sweet as. I'm trying to image at f10 atm with a 2000mm FL. Let's see how good my autoguding through an ED80 goes with that

[ballaratdragons (Ken)]

Yep, guiding looks great by the graph. Only about 2.5 arcseconds drift.

In the image above, I can't see the oval shape as the left image doesn't show up on my monitor very well. I can only just see the faintest arc.

[ballaratdragons (Ken)]

I see it now!!!! I took it to PhotoShop and brightnened it.

Dang, that's bad!

[[1ponders] (Paul)]

And most of that is seeing.

[Garyh]

yeap..does look like something has fogged up on you Paul. look forwards to when you get the ED80 up and running!!

[rat156]

Hi Paul,

I also have the Meade focal reducer, and have used it succesfully with the SBig. The pics you're showing look like it's outside the focal distance for the FR. How do you have it attached to the SBig? Do you have a CFW as well?

When I use mine it's attached to a cheap 1.25" VB, which is about an inch long and has t-threads on the 1.25" end, these screw directly into the CFW. Then the FR is screwed on the front and a 2" SCT adapter on the front of the FR into the focusser. I get some coma towards the outer edge of an ST10 chip, which is far bigger than your ST7 chip. I used to have an ST7, don't remember any problems using it. I generally use an Optec f5 reducer now (bought from IIS), the back focus distance is set for ST camera with CFW, it's great for an ST7 sized chip, but the ST10 presents it with some problems. I have double stars on the guide chip (don't ask me why, but it happens with the Meade FR as well, so I think it's just getting towards the edge of the FR range).

The optimum FR to CCD distance varies depending on who you talk to, but 87mm is the current best thinking, closer seems to be OK, further away is not on from my experience.

Cheers
Stuart

[[1ponders] (Paul)]

I have the Meade FR with a 2" SC Adapter screwed into the female side and that slides right into the JMI focuser. On the camera side I use the standard Meade SC thread to T thread adapter (about 50mm long). This then screws directly into the CFW. I thought the Meade FRs optimal focal distance is around 105mm from rear element to imaging surface.

I tried a number of different arrangements with the FR last night as far as filters are concerned, none, clear, red, green and blue and they were all difficult/impossible to get a sharp focus.

I have the WO 0.8X that I might try with the ED80, but I think I will need to get the Optec Nexgen 0.5x reducer for the SCT, 0.8 really isn't enough. I've been putting off getting the nexgen one, but I've never been really happy with the meade one. Oh well ....another gadget

I'll also take out the desiccant this weekend and give it a bake and see if that makes a difference.

I'm at work atm so don't have access to last nights images. I'll process them and post them when i get home this afternoon. I was still disappointed in the focus result even after removing the FR.

[[1ponders] (Paul)]

btw the image of the defocused star using the FR above looks very much like astigmatism to me.

[rat156]

Hi Paul,

There was a bad batch of Meade FR's out there...

If you were closer to me I'd say drop around and borrow my adapter.

I've sent a question to the Optec people about my reducer, if I can't get it to work, I may be selling it, so hold onto them peso's for a while.

Looks like I'm in for the Ted Agos solution as I have the AO7 as well...

Cheers

Stuart

[[1ponders] (Paul)]

which solution is that Stuart?

[rat156]

http://www.ziplink.net/users/lester/FLR.html

[[1ponders] (Paul)]

Ah yes I remember finding that ages ago. My setup is the one on the left. I'll be interested to see how that one works out Stuart. I think I'll use the 0.8 with the ED80 (which should focus) and have a think about which FR to get. I've heard good reports on the NexGen one, I wonder how the Celestron 6.3 compares?

[Dr Nick (Nick)]

For a first, i'd be fairly happy with it if i were you!

[[1ponders] (Paul)]

Oh I am Nick, the fact I've actually managed to get a recognizable image first night out is a pretty big bonus for me