Skywatcher 200P vs Canon EOS-20D

[NightDreamer]

Hi,

First off, I'd like to say thanks to Martin @ First Light Optics who's been very helpful in getting my new 200P DS out to me, and for giving me some great advice. If anyone's considering using FLO I'd highly recommend them.

Last nights weather wasn't best for viewing, but even so it's clear the scope is a huge step up from the 130P I had before.

On the 130P I had to use a Barlow to get the 20D to be able to focus, and I wasn't expecting this on the 200P. Am I doing something wrong?

Is there any way to hook the 20D up to the scope and not use a Barlow? The extra magnification exaggerated the impact of the wind and meant I couldn't get much of Pleiades in the frame.

Many thanks,

Nick

[malc-c]

Welcome to SGL

Are you saying you are having problems connecting a Canon dSLR camera body directly to a 200P ?

You should be able to use a T ring between the body of the camera and focuser coupler, no need for a barlow

[NightDreamer]

Hi Malc-c,

No, the camera attaches fine, just as on the 130P.

The problem is in achieving focus. To get things sharp I can't wind-in far enough with the 1.25" adapter, but putting a Barlow on fixes this.

I've been trying to avoid opening the 2" adapter Martin @ FLO suggested (trying to save the pennies after spending a wad), but perhaps that will give me focus?

Thanks

Nick

[Carl M]

I'm guessing the PDS doesn't have a Direct SLR connection? With my normal 200P I can remove the 1.25" adapter and attach the T-ring straight to the focuser

[malc-c]

Nick,

I'm having problems visualizing how you are trying to connect the camera to the 200P. Unlike some of the other SW scopes the 200p's focal point is far enough outside the tube that focusing isn't a problem.

If you remove the adapter from the draw tube buy undoing the thumb screws at the end of the focuser, then unscrew the tube from the adapter (where you normally place an eyepiece) you are left with a ring, with a thread on both sides of the lip. You attach the T mount to this ring and the T mount to the camera body, then attach the lot back to the draw tube.

Hope that helps

[malc-c]

I'm guessing the PDS doesn't have a Direct SLR connection? With my normal 200P I can remove the 1.25" adapter and attach the T-ring straight to the focuser

Ahhh I missed that.....

[Cornelius Varley]

You should be able to acheive focus if you remove the 1.25" adapter and connect the camere body to the T thread on the 2" part of the focuser adapter. The DS version of the Explorer range are designed specifically for this. Watch this video from Youtube Connecting a SLR to telescope

Peter

[NightDreamer]

Thanks everyone for your replies.

I feel very stupid - I'd not realised that the barrel used by the 1.25" eye piece was removable and left the 2" thread I needed exposed.

Sadly, lightning (and more importantly) clouds have now closed in and I can't check it out.

Before they moved in I got a rather poor picture (Barlow and all) of Andromeda... 60 mins setting up and trying to align for 2 x 3 minute pictures - not a great night.

One of the 3 minute sub is attached (no processing) if anyone has any advice - I would have thought if it was just drift the star trails would be straight from bottom right to top left, not look like an upside-down v..? I don't remember anything knocking the scope, or any particular wind.

First picture is the whole frame, second is zoomed in to show the funny shaped trail.

I did see the ISS go over earlier in the night so not all lost

[malc-c]

Was this through the 200P ? what mount do you have it sitting on EQ5, HEQ5, EQ6 ? Had you polar aligned the scope ?

[NightDreamer]

It was through the 200P, on an NEQ6 Pro. I polar aligned through the polar scope, then attempted my 2nd drift alignment using WCS.

The offending Barlow was a x2.

[malc-c]

Hummmm... nice solid mount, but it does look as if something shifted half way through the exposure.

[NightDreamer]

If by "nice solid mount" you mean "extremely heavy to move in and out" - yes it is!

As a side-note, do most people normally move their kit assembled, or take it apart for moving the 20' from inside to outside? With both 10kg counterweights on I dread to think how much this weighs.

I'd agree it looks like something knocked the mount, but both of the two frames I took tonight have the same shape trail on.

I wasn't using mirror lockup on the camera, figuring the amount of light let in while the mirror moves is minimal on a 3 minute exposure - could this be the culprit?

[Black Knight]

Try it next time with mirror lock enabled. It might make a difference. You did mention the wind though, it could be that. I used to get that problem a lot with my 200p. A big newt acts like a sail in the wind. I still get problems from time to time if there is much more than a light breeze.

[Black Knight]

I feel very stupid - I'd not realised that the barrel used by the 1.25" eye piece was removable and left the 2" thread I needed exposed.

That's quite a common occurance actually. It took me a good long while to figure it out too. The sales blurb quotes a "direct camera connection", but the manual doesn't explain how to achieve it .

As an aside, you may find it useful to check out BackyardEOS or APT to automate exposures using an EOS DSLR. I've never used BackyardEOS, but have quite a bit of experience using APT. You'll probably need a serial or DSUSB cable to automate bulb exposures though, but still well worth checking out.

[NightDreamer]

Thanks Andy, I'll give BackyardEOS a try. I'll also switch on the mirror lockup function. Hopefully I'll get something a bit more stable, but with the rain outside I don't think it will be tonight

[ollypenrice]

I think your mount took a knock or had a cable momentarily snagged. An NEQ6 won't deliver unguided imaging (hardly any will do that even at twelve thousand pounds) but the V shape is not the normal periodic error.

Olly