Using PHD

[Interested]

2nd question today!

My guide scope is now firmly bolted on top of my main scope.

Does the guide scope need to look at the same area of space as my main scope (I asume, the reason for Guide Scope Rings?)?

Or, can I slew to the object I want to image, and once it is framed ok in my camera, look for a bright star in the FOV on the PHD screen, click on it, and start guiding?

Or isn't the software that clever?

Setup is ST4 cable from QHY5 to mount.

Many thanks (again) for any advice.

[Bizibilder]

The adjustments on the guide scope are to allow you to find a suitable guide star. So, as you say, find and centre your target, focus and check alignment (maybe take a couple of short exposures just to be sure!), then move the guide scope to find a suitable star, let PHD calibrate, allow a minute or two to "settle" once guiding, set the camera taking subs. Sometimes you are lucky and a guide star falls in the fov of the guide scope!

I've just bought the adapter to use my QHY5 on a SW 50mm finder - with a much bigger fov than my ST80 - but havn't tried it out it yet due to the clouds!!

[Photosbykev]

If you are running EQMod to control the mount you can get rid of the ST4 cable and use the output from PHD to feed into EQMod which will make the necessary adjustments.

[Interested]

Thanks Bizibilder - my ST80 is bolted to the top of my main scope using just the clamps that came with the scope so no adjustment possible. I'm hoping that generally, there will be a star in the FOV that I can use to guide on. If that turns out not to be the case then I will need to mount the ST so there is some adjustment!

Kev - I'm not using EQMod at this time but I intend to look at it's use in greater depth in the near future.

I'm in Mid-Wales this weekend, with a cracking dark sky on a clear night, however, it's been nothing but low cloud, wind and rain so far

Back to work on Tuesday, I'm daresay the skies will clear then!

[Photosbykev]

I use a ST80 and QHY5 as a guidescope and I've mounted it in 120mm guide rings to give me some movement as sometimes I've had to look around for suitable guidestar.

[Zakalwe]

I was using an ED80 with a QHY5 to guide, and I have always found a star to guide with. The ED80 was mounted in non-adjustable rings. I have, this weekend, moved to a finderguider, using an adapter from Modern Astronomy to mount the QHY to the finderscope (same as Bizbuilder)

In answer to the OPs original Q, AFAIK, as long as you can lock onto a star PHD will work out the orientation during it's calibration routine. Dont forget that you can alter the length of exposure in PHD to make dimmer stars appear a bit brighter (and a longer exposure stops the guiding system from "chasing the seeing". I get good results with an exposure of 2.5 seconds)

[Interested]

Thanks Zak,

Always good to know what settings other people are using. I'll try 2.5s as a starting point.

I guess using a finder scope might be a good option to save weight and bring the CofG of the main scope back a bit.

I'll see how I get on with the setup I have for now but will certainly consider a 'finderscope solution' for the future!

[Big Jim Slade]

I've got an ST80 and QHY5 bolted to the top of my 150P and general can find something to lock on to without the need for guidescope rings, so far.

I'd agree with Zakalwe (even though his avatar freaks me out) that a slightly longer exposure is better.

[Freff]

Same here, my ST102 is fixed and I have not failed yet to find a suitable star in the FOV.

[Zakalwe]

I've got an ST80 and QHY5 bolted to the top of my 150P and general can find something to lock on to without the need for guidescope rings, so far.

I'd agree with Zakalwe (even though his avatar freaks me out) that a slightly longer exposure is better.

Soz about that:o

[martin_h]

I have my ST80/QHY5 in guide rings but to be honest I've never moved it from day 1, I've never had a problem finding a guide star.

[Steve 1962]

I have a WO ZS70 with a QHY5v rigidly bolted to the top of my SW 200p and that works a treat. I have no idea if the two scopes are looking at the same thing.

Steve