QHY5 - colour or mono

[Prickly]

Im planning to get a QHY5 autoguider and trying to work out which way to go: colour or mono. I would also like to use it for looking at planets. Probably it will get more use with autoguiding I suspect.

The mono is more sensitive and with filters etc you can probably do nice planetary shots. But the filters / filter wheel is quite expensive I gather (Im guessing maybe around $700 or so?).

On the other hand the colour seems to do some pretty amazing planetary imaging and even though it cant quite match in resolution doesnt probably suffer from planetary rotation so much presumably.

See here some colour images.
http://www.qhyccd.com/QHY5.html
(OK - yes an 5 inch apo too)

Overall Im thinking the mono should be best but I look at those jupiter images and I just wonder. Probably much easier than all the filters etc.
But the sensitivity may not be so great - has anyone tried a colour QHY as an autoguider? Id be using a C90. How do you think it would go?

I thought a post to the group might help sway my decision in one direction.

Cheers
David

[Bassnut]

The QHY5 mono is excellent for guiding, dont try to go cheap and get a colour one to use for imaging too, get another cam for that, sheesh, cheapskate :D.

[Prickly]

I like your thinking there ;) . Not that an orion filter wheel and set of astronomik filters in the Xmas stocking would upset me too much either.

Im probably swaying to mono but thought someone out there might tell me the colour was also brilliant. Ultimately you probably have more choice of guidestars with the mono and it has to be better.

What sort of magnitude can you pick up with 10secs or so with a mono by way of example do you reckon (depends on scope too of course)?

Cheers
David

[Bassnut]

I have never had to go longer than 2 secs guiding exposures with the mono QHY5 on a ST80 guide scope, period. I dont know what the min mag is, who cares, it works. Beware, the colour version is less sensitive, I wouldnt bother. Get a QHY8 for imaging ;-). Just as a byline, the QHY5 starts to get marginal for guiding at 15secs or more, from experience on my automated GRAS rig, but with my home rig, it has been brilliant at 2 secs for everything.

Guiding is the single biggest influence on image quality, the mono QHY5 makes it a no brainer for most rigs, dont mess with it, set and forget. Worry about imaging seperately.

[Prickly]

Thanks Fred,

Its hard to argue with a winning formula. I think the mono is the way to go.

I gather the QHY5's dont require any additional adapters etc with the Eq6 because the pin layout is ST4 compatible. If anyone confirm this that would be appreciated.

Cheers
David

[mrsnipey]

That's correct David. I got a cable with my QHY5 (mono) and it works perfectly with the EQ6. Plugs straight in.

[Prickly]

Thanks All,

Im decided now. Mono. Thanks for clarifying too there are no issues to with the Eq6 pro.

Cheers
David

[mrsnipey]

Good choice if you're using it for guiding. I can't comment on imaging with it as I only use it for guiding. It's amazing how good it is. It tracks for hours on even the faintest star on 0.5 sec exposure.
The only part I had problems with was getting the right settings in PHD Guide but that was my fault for not reading the instructions. I never do.

Round stars await...

[Terry B]

I use my mono guider through a 120 x 600mm achromat. For most areas of the sky I get a guide star with a 0.5 sec esposure. It is uncommon not to have a suitable star with a 1 sec exposure. It is very sensitive.

[Prickly]

Thanks Terry and MrS,

If it guides then everything else is a bonus - and it looks like it does that well.

Cheers
David