Last night (Valentine's night)

[Carole]

Wow, what a night, can't remember one as good as that for ages.  Clear all night and no chance of rain.

It is also the longest night I have ever stayed up, though I did cheat a bit and go to bed twice for an hour or so's sleep each time.  Can't remember the last time I risked doing that either.  Plus I had the dome off on the Dome table, so no chance of getting that back on quickly, was putting it back just as dawn was breaking.

Finally got to bed at dawn.  I do sometimes do this at DSC, but dawn arrives much earlier then. 

Supposed to be clear again tonight until midnight, so am planning the 2nd of the four Rosette panes.

Was getting bored with the Rosette last night, so when it was behind the trees again, I chose a different target which was at the Zenith and having got my dome off, I decided to stick with it.

Any-one else out last night?  Though thinking about it I was doing narrowband which might not have suited those with OSC cameras.

Carole

[ApophisAstros]

Nice one Carole,
Roger

[The Thing]

I was imaging last night, M81-M82 and M101 but more as a proof of camera settings and equipment setup than serious imaging, the Moon was bright. Guided all night. However I think cooling the ASi294 MC Pro to -20C is a problem, tonight I am going to try 0C. It is due to the CMOS chip design and subsequent limitation on cold finger placement, so the chip is not evenly cooled. I think the bigger the variation the more blotchy the image becomes. Maybe I'll find out tonight, its a bit murky but not too bad. Doesn't really matter for my purposes.

[Carole]

Am out again tonight, but only supposed to be clear until Midnight.

Duncan, I don't cool my camera to the maximum it can go, I keep it to -10 or -15 and that way i can use the same darks summer and winter unless there is a real heatwave.

Carole

[The Thing]

Duncan, I don't cool my camera to the maximum it can go, I keep it to -10 or -15 and that way i can use the same darks summer and winter unless there is a real heatwave.

Carole

I concur, I was using -10C to -15c in the summer as that was achievable. However from what I have read my camera has a physical problem with temperature gradients from the middle to the edges as the edges aren't cooled by the cold finger. So the answer is cool it less and see if the blotches and other issues lessen.

[Carole]

my camera has a physical problem with temperature gradients from the middle to the edges as the edges aren't cooled by the cold finger. So the answer is cool it less and see if the blotches and other issues lessen.

Gosh that doesn't sound good.  Seems to be a very problematic camera one way or another.

Carole

[The Thing]

Apparently they now say the ZWO ASI294MC Pro is for Electronically Enhanced Astronomy EEA, in other words an expensive electronic eyepiece. On paper it very good and some people are getting excellent images so I'll persevere for a bit longer then may have to move it on.

[RobertM]

Duncan,

Is the camera faulty ?  I've seen some good images on other web sites so there must be something wrong with yours mind you I have also seen some blotchyness on a few.

Have you raised the issue on the ZWO forum ?

Robert

[The Thing]

I have been on the ZWO forum today, not for the first time. I'm trying a new idea tonight - when I first got the camera I used the supplied USB3 cable to connect it directly to my laptop. I got some good subs. Then I got a powered USB3 hub and I appear to have had the problem since. Possibly. So I'm trying that tonight. The big moon is not important for this purpose.
Also I have updated the camera driver as new versions have appeared. ZWO name all their downloads the same so it not easy to keep the previous version. I have asked if I can get an old version from ~Jan 2018 to try in case that is the problem.

If I can't solve it in the next couple of weeks I'll get a different camera...

[ApophisAstros]

I have been on the ZWO forum today, not for the first time. I'm trying a new idea tonight - when I first got the camera I used the supplied USB3 cable to connect it directly to my laptop. I got some good subs. Then I got a powered USB3 hub and I appear to have had the problem since. Possibly. So I'm trying that tonight. The big moon is not important for this purpose.
Also I have updated the camera driver as new versions have appeared. ZWO name all their downloads the same so it not easy to keep the previous version. I have asked if I can get an old version from ~Jan 2018 to try in case that is the problem.

If I can't solve it in the next couple of weeks I'll get a different camera...

Just wondered how big each of your colour subs (LRGB) are compared to my mono ones (L or R or G or B)is it 4 times bigger and can the usb hub handle it.Is that the crux of your point.
Roger

[RobertM]

Duncan,

Have you tried powering the camera off battery, or rather, powering any noisy equipment like dew heaters off a different supply ?  Also connecting the camera usb direct to the computer usb3 port.  You could also try unplugging the power lead from the camera an using usb only.

Robert

[The Thing]

Hi Roger, the camera is USB3 as has been the hub, it also has a big memory buffer, I don't think raw 16bit data transfer is going to strain it.

Hi Robert, last night with direct connection of the camera to the laptop I got significantly better subs(!). The sky was less murky but the moon brighter than the previous night. I'm using M81-M82 as a target as its far from the Moon. I'm doing matching calibration frames inc. darkflats right now.
You are right the next thing to try is not powering the cooling, I don't have a 12v battery of any description unfortunately so I can't go that route.
I'm also going to trawl my hard disk and see what early/first light images I can find for comparison to those I'm getting now.

PS Sorry for hijacking your thread Carole!

[Carole]

No worries Duncan, it's all useful info.

Carole

[MarkS]

Wow, what a night, can't remember one as good as that for ages. 

Valentine's Night?
I was getting worried what you might say next!

Mark

[Carole]