Suggestions please - guide camera selection

[RobertM]

Well worked out Duncan, just goes to show what a bit of determination can do !

Mick, you worshiping beer again

[The Thing]

Well, the QHY5 definitely performed better, there was very little banding in PHD2 when I had a star or two in the FoV and only a little fuzziness. I'm happy but it's still not sensitive enough for use with an OAG at f6 or f10 and be certain of getting a usable star.

Meanwhile I found this very interesting comparison of a Lodestar vs a QHY5L-II on Cloudy Nights. I think a QHY with my name on it might be finding it's way into Santa's sack (I'm sure the postmans' called Santa).

[MarkH]

Horizontal adjustment  yeas I remember that

[The Thing]

I am now the owner of a QHY5L-II Mono. Happy Christmas to me!

[Mike]

Yay! \o/

Just in time for DSC too!

[JohnP]

Nice one Dunc. It'll be interesting to do your same bedroom test.... Did you get it from Bernd...? John.

[The Thing]

Yes, I got it from Bern. He did a deal on the Deluxe kit which was nice. I tried it out on the laptop and and could get ~250fps at the lowest res 320 x 240 directly connected to the USB3 port. I used that one as there is nothing else connected to its controller.

I can't repeat the test as the lens with Robert's ASI120MM is very different to the 8mm f1 supplied with this kit, I get a much wider FoV. The kit also has a 1.2mm 180 degree f2 lens for all sky imaging and I would really like to try it out. The Deluxe kit contents all seems very good quality and I would be hard pressed to source the lenses for the price let alone the tripod mount etc. The tin it come in is another matter!

Now I've got to see how the camera goes in the OAG EP fitting - no T-threads.

[JohnP]

cool - so I am guessing it would make quite a nice planetary imaging camera as well..

[Mike]

Great! With the all sky lens you could get live video of meteor showers too.

[Rocket Pooch]

cool - so I am guessing it would make quite a nice planetary imaging camera as well..

It should do but I don't know how many times people talk about FPS when the exposure is say 1/100th second or down to 1/30th which means you can't get 150fps.

No doubt somone wil now talk about noise.

But this camera looks great.

[The Thing]

The new guide cam was excellent, it took a full lump of cloud to lose a guide star in PHD.

PHD had trouble recognising the blobs the old QHY5 presented amongst the noise as stars and quite often started following a bit of static instead of a star as soon as a bit of murk went across the FoV.

One downside is the much smaller chip so there is a smaller patch of sky to find a star in. The QHY5 showed about 20% of the view of the DSLR even through an OAG! The QHY5II-L shows about 8% at a guess.

Also mounting the camera in the Brightstar OAG isn't the best bit of engineering. Firstly you need an eyepiece extension tube to reach focus. I used a Barlow with the lens cell removed. The QHY5 was screwed on with a T-Mount extension. The QHY5II-L is therefore not so solid and I am going to have to get a CS mount male to T-mount female adaptor to remedy this.

Focusing the camera is difficult due to the engineering of the Brightstar unit. I am exploring helical focusers and will probably modify an old lens (rip all the innards out and glue on T fittings) to do this which will also solve the eyepiece extension problem.

I did a few vids of Jupiter at about 50fps and it looks promising as a planetary camera. Images to follow on an appropriate thread!

[JohnP]

cool - yes the brightstar has a real crap focus mechanism....

[Rocket Pooch]

I focus mine in the daytime makes it 100% easier to do.

[The Thing]

Did that on the distant pylons in the north east gap between the trees at Blacklands. The knurled screws don't hold very well and the sliding action of the camera holder is pants. On top of that the fine focus rotating bit is very rough. I even put a dab of boron grease on it but it made no difference as the thread is compromised by the locking screw tightening on it. Clever engineering not. Maybe I got a Friday model . I previously have had to detach the prism and re-glue it as it was wonkily sitting on a blob of glue in one corner. I would spend more next time.

[JohnP]

Dunc - I don't even bother fine focussing mine - as long as its close. My guide stars are like distorted crescent moons & the guide software still finds the centroid.. Also, my filters all focus at different places anyway & there is no way I am changing the focus of the Brightstar OAG in middle of a cold night if I change to a different filter...