QHY5L-ii problem?

[Thalestris24]

Hi

So, since late January I've been using the qhy5l-ii as a guide camera - initially on a 9 x 50 finder, more recently on an ST-80 - but have always had problems... I've put it down to being in Glasgow with lots of lp and poor atmosphere transparency. But.. now I'm wondering whether it could be the qhy5l-ii itself. After a frustrated attempted imaging session last night I decided to put it back on the finder today. As I was doing that I did some tests on it. One problem I've had is that the brightness of the display window in PHD 1 or PHD 2 fluctuates randomly between light grey and a darker grey with any exposure (usually 1.0 - 2.5s). I've also had problems selecting and keeping a lock on guide stars. I've been testing today with the finder and with the lens cap on and lens end covered in foil and a black bag to keep the light out. But I still get a grey, fluctuating display, never dark, let alone black. This is with the gain turned down to 1 and even with the shortest exposure. I've tried in both PHD1 and PHD2 and with both the native and ascom drivers. I've tried with different usb cables and different usb ports - the same problem.

Am I expecting to much of an uncooled cmos camera? Do PHD1 and PHD2 automatically try and boost the displayed signal? But even so why the fluctuations in brightness even in normal use? Does anyone else experience this with a qhy5l-ii?

Any help or advice greatly appreciated!

Thanks

Louise

[Thalestris24]

I did another quick test selecting my qhy8l as 'guide' camera. Got a dark grey, noisy screen with the scope covered but no fluctuations in brightness..

So I'm thinking the qhy5l-ii is faulty (and always has been!) unless anyone has any other ideas/suggestions?

Louise

[lensman57]

Test the camera during the daytime using sharpcap and phd and ST80 and see if you get a steady image. . That is what I used to do wth my Opticstar 131 AG and AS|I120 to verify that the driver is working fine,  if it is then the problem is elsewhere and not the camera.

A.G

[ChrisLX200]

PHD does that, it does it with my QHY5L-II and also my Lodestar, though perhaps not as much as your description suggests? You need to test the QHY with Sharpcap or Firecapture or something like that, a capture program that you can set the exposure/gain/display values (and they stay put).

ChrisH

[Thalestris24]

Test the camera during the daytime using sharpcap and phd and ST80 and see if you get a steady image. . That is what I used to do wth my Opticstar 131 AG and AS|I120 to verify that the driver is working fine,  if it is then the problem is elsewhere and not the camera.

 

A.G

Hiya - yeah I have been. I think it's just me! What's bothered me, I think, is the way PHD seems to continually auto adjust the display brightness. I know this has nothing to do with the way it uses the captured images to calculate centroids, but still. I'm still concerned about getting it to lock on to stars and keeping the lock. PHD/2 both seem very fussy. Anyway, I'm going to try the qhy5l with the finder next time. It's all set up raring to go now. Just need some clear skies... One of these days I'll get some decent guiding! It's frustrating when I know the mount will track for 60s but guiding makes it go off - defeats the object!

Cheers

Louise

[Tinker1947]

I haven't read the thread from the start, so if good quality USB leads or what ever type it uses have been mentioned this is another poke in that direction, or RF getting in the USB lead, get the lead away from anything else...

[lensman57]

are made to the

Hiya - yeah I have been. I think it's just me! What's bothered me, I think, is the way PHD seems to continually auto adjust the display brightness. I know this has nothing to do with the way it uses the captured images to calculate centroids, but still. I'm still concerned about getting it to lock on to stars and keeping the lock. PHD/2 both seem very fussy. Anyway, I'm going to try the qhy5l with the finder next time. It's all set up raring to go now. Just need some clear skies... One of these days I'll get some decent guiding! It's frustrating when I know the mount will track for 60s but guiding makes it go off - defeats the object!

Cheers

Louise

The QHY5lii has very small pixels, same as the ASI 120, I would not use it with the ST 80 unless some serious adjustments are made to the PHD settings, perhaps you could change the min search settings alongside the min motion pixels. I think with the 50mm finder guider you should be fine.

A.G

[Thalestris24]

The QHY5lii has very small pixels, same as the ASI 120, I would not use it with the ST 80 unless some serious adjustments are made to the PHD settings, perhaps you could change the min search settings alongside the min motion pixels. I think with the 50mm finder guider you should be fine.

 

A.G

Hi

Yeah it could be that my settings haven't been optimal.. As you say, the finder should be less sensitive to certain parameters.

I've just been reading this: http://acp.dc3.com/McMillanAutoguiding11-2005.pdf

I've previously read Craig Stark's publications about autoguiding. Useful to stop for a minute and study things. It would be good to have software that could guide on several stars. Maybe one day

Louise