Mono Log - A cooled mono cam.

[Stub Mandrel]

As the supreme cheapskate, I've decided to see what can be done with my Touptec Mono. (Edit this starts as a build log and rapidly degenerates into why won't Sharpcap save frames with long exposures??!!!)

This has a webcam-sized chip the same one as used by the ASI120MC (and supposedly better than that in the ASI 120MM).

I've taken it apart and made an aluminium plate to fit a peltier cooler with a copper stalk on  to cool the chip. I'm still working on the 3D printed housing, so for tonight I'm just going to try it out with 2-minute subs and see if I can get some very basic mono data with the 130PDS.

It's a change to be looking for small DSOs! It's pixels are about half the size of those on my DSLR and well matched to the 130P-DS at about 1" per pixel, recently my guiding has been at ~0.75".

I bought a USB3 hub but it doesn't want to work for me. Found three old USB 2 hubs, one worked with a mouse but wouldn't work with anything else. Then I found a good one and I was able to run mouse and mount off the hub, so no worry about power through it.

Got everything working in the living room, including PHD2 on the ASI120MC and Sharpcap with the toucam.

I've found the special short 2-1.25" adaptor I made so hopefully I can focus - but will I be able to find anything?? At least the FOV is six times bigger than when I do planetary so hopefully it won't be too hard.

Prepared darks in Sharpcap, but I might not use these and take some later at a closer matched temperature.

If i get something, then it will be worth persevering with cooling, then moving on to proper LRGB. If that all works, then maybe a big cooled mono cam, if not maybe a cooled OSC cam.

Fingers crossed.

Edited September 19, 2019 by Stub Mandrel

[Dr_Ju_ju]

You'll never know unless you try it.....

[JamesF]

I look forward to reading how you get on.

James

[Stub Mandrel]

Well the trial this evening is a disaster!

Alignment is fine.

This  afternoon I happily took 24 5-minute and 24 2-minute darks while having PHD2 running on the other camera, no trouble.

Now, Sharpcap drops every frame except the first unless the duration is 7.5 seconds or less.

PHD2 takes about four attempts to link to the guider.

Exactly the same settings and wires, only difference is that I'm outside. I even had the mount tracking this afternoon.

I'm despairing. My laptop seems to have become totally unreliable, I can only imagine its due to a change in windows. Robin @rwg are you out there? Do you have any ideas?

[JamesF]

You're still using the same USB2 hub as you were using indoors, too?

James

[Stub Mandrel]

25 minutes ago, JamesF said:

You're still using the same USB2 hub as you were using indoors, too?

James

Exactly the same one, and it only has the mount and mouse on it. Everything on the same ports.

At least  PHD2 seems to keep working once it's started now.

I'm capturing 7.5 second subs, as it only seems to drop less than half of the subs. 15 second subs the most I got was three before it refused to get any more, 15 dropped. It even gets to odd 30-second sub - but only ever reliably loads the first capture. On short exposures - a second or two or less it captures every frame. It just doesn't make sense to me.

Edited September 1, 2019 by Stub Mandrel

[Davey-T]

Sounds like a USB bottleneck of some sort, haven't used Sharpcap but Firecapture has some sort of USB throttling setting.

I don't think taking darks is the same as taking lights, not that I know much 😂

Dave

[JamesF]

I wonder if the camera behaves strangely when the image is as good as totally dark (which it might well be if you're sufficiently far out of focus).

Could be worth pointing it at something bright (assuming you can find anything) and retrying?

James

[Stub Mandrel]

No, I was spot on for focus. I tried all the different USB speed options.

Going down to 3.2 second frames - every one works, then going up, most 7.5 second ones work, 15 seconds about 1 in 4, 30 seconds hardly any. The only way to get a long exposure was to set the exposure, close and rew-open sharpcap then the first one would work - showing M16 and even the pillars of creation! But start capturing and drop almost every frame.

There is something on the sharpcap forum that suggests this is an issue with new ZWO drivers and that old versions of Sharpcap might work better, but that wasn't really something practical to  try. This one uses teh Altair GPCAM driver but might have a similar issue.

[JamesF]

Touptek have their own fairly rudimentary imaging application.  That might be worth a try, though I'm struggling to believe it's merely a software issue when you had it working indoors.

Definitely worth setting it up again to try indoors today, I reckon.

James

[Stub Mandrel]

Results of the experiment!

Four frames of about 2 minutes

One of about 30 seconds

Ninety five of about 7.5 seconds

Lots of dust!

Poor aim!

Unmatched darks!

No Flats!

No cooling!

Iffy focus!

Some potential, but a lot of work needed.

[Gina]

Well, it's recognisable as "The Pillars of Creation"

[Stub Mandrel]

I was thinking of entering it as an APOD...

Noise and dirt aside, it does show some subtle detail the DSLR didn't pick up (notably small stars), will be worth cleaning and cooling:

Edited September 5, 2019 by Stub Mandrel

[Stub Mandrel]

I've successfully printed the enclosure and now fitted the heatsink to the peltier and fan for a test and it works.

Tomorrow I will photograph all the bits and assemble it, then I have to make lids for the electronics and desiccant chamber (just a box to put silica gel in) then make a carrier to take 1.25" filters to seal the sensor chamber.

[Stub Mandrel]

Success, I just took two 10 minute subs. Both in my 'office' where the temperature is currently 25 degrees, thanks to computer and busy 3D printer. Here is the dark taken before connecting the cooler, and the dark taken afterwards... Both 600-second PNG captures out of Sharpcap with no processing. Can you guess which is which 🙂

The 10 minute cooled sub is indistinguishable from a 2-second one.

[Stub Mandrel]

A few pics. the lids for the electronics and the dessicant are  printed 0.2mm under nominal size and 'click' in with the surface texture. I may fit an internal holder for a 1.25" filter, to create a smaller sealed chamber for the dessicant.

The sensor already has a small rectangle of heatsink putty on it which connected it to a stalk inside the case.