PHD2 + Altair GPCAM2 IMX224 trouble

[ecuador]

I've been happily using PHD2 with a QHY5L-II mono and a mini-guide scope for a while now, almost always leaving the exposure at 0.1s. I wanted to go to a OSC for simpler planetary imaging, so I got the Altair GPCAM2 IMX224. I thought, better sensor, but color, so I'll probably have to use a bigger exposure when guiding, but, say even 0.2s is a fine exposure to use and it is twice my previous so it should do fine.

Well, I am seem to be having some trouble that don't remind me how it was with the QHY5 when the stars were faint (i.e. I would see more noise as PHD2 was apparently increasing gain and also get some red flashing screen). What I am getting is clear stars even at 0.1s, with a green SNR, but flashing white and "losing" the star at a constant interval, increasing the exposure to 0.2, 0.5, even 1 sec does not change this behavior, e.g. in the 1 sec I could clearly measure 5 "normal" frames, with a very high SNR and suddenly a white frame with "star lost".

Take a look at a short screen capture video: https://drive.google.com/open?id=0B1c3jz2L9HfgeGdZQjQxemxuRTQ  you can see at 0.5s the SNR is 60, the selected star is very bright and clear, and yet there is this flashing, always at perfectly regular intervals.

Anyone has an idea what it is I am seeing? Am I having an issue with PHD2 or with the camera?

TIA!

[alacant]

Hi. 0.1s? That must be really good seeing. The best way to get the correct exposure is to use the PHD2 guiding assistant. let it run for at least a minute and just take the suggested settings. Let PHD2 choose the guide star itself; take the guesswork out of it all. HTH.

[Dr_Ju_ju]

Why not still use the QHY\mini-scope for guiding and then you can use your OSC for capturing images...

Also have you taken new dark\bad pixel maps ??

[ecuador]

30 minutes ago, Dr_Ju_ju said:

Why not still use the QHY\mini-scope for guiding and then you can use your OSC for capturing images...

Also have you taken new dark\bad pixel maps ??

I sold the QHY to get the Altair

Yes, I took dark\bad pixel maps.

 

36 minutes ago, alacant said:

Hi. 0.1s? That must be really good seeing. The best way to get the correct exposure is to use the PHD2 guiding assistant. let it run for at least a minute and just take the suggested settings. Let PHD2 choose the guide star itself; take the guesswork out of it all. HTH.

It is an f/3.6 guide scope and a sensitive camera, I don't think it has to do with seeing. I have never had to use any assistant in the past, I mean it had become obvious to me if the exposure is enough and if a star is bright enough, I never had a problem. But the thing is that if I underexposed with the QHY, the behavior was different from what I am seeing, so I want to make sure there is no miscommunication between the Altair and PHD, or something else I am missing...

[Dr_Ju_ju]

Have you tried using SharpCap & made sure that the new camera is working & focused correctly.

I have also used a QHY5L-II for guiding, but now I use a ASI120, and I was surprised at the difference in focus point between the 2 cameras.

[ecuador]

42 minutes ago, Dr_Ju_ju said:

Have you tried using SharpCap & made sure that the new camera is working & focused correctly.

I have also used a QHY5L-II for guiding, but now I use a ASI120, and I was surprised at the difference in focus point between the 2 cameras.

I used Altair capture to make sure the camera works correctly. Did you see the video? There's some well-focused bright, clear stars there, marked as 60+ SNR between the flashes... I thought that is pretty weird, is that supposed to happen?

[rwg]

Try a prerelease version of PHD2 from here - http://openphdguiding.org/development-snapshots/

There have been a lot of updates to the Altair SDK and the code related to running the camera since the last release build which was back in July.

cheers,

Robin

[ecuador]

3 hours ago, rwg said:

Try a prerelease version of PHD2 from here - http://openphdguiding.org/development-snapshots/

There have been a lot of updates to the Altair SDK and the code related to running the camera since the last release build which was back in July.

cheers,

Robin

Thanks, I'll give that a go.

[ecuador]

Yep! That was it! No weird white frames, I can go down to 0.1s again