Starlight Xpress SX-694

I bit the bullet and finally bought a used SX-694 mono camera, my first SX camera, which I’ve been eyeing for some time now. Quick question, does SGP support these cameras natively or ascom only? Doesn’t make any difference to me, but I’d like to know if I need to find the SX ascom driver.


You will the Ascom driver from here

Not tried it with yours , but should be ok


Thanks Harry. I just found that right before your message. Seems like that ought to be on the SX website…

Looks like there is an ASCOM driver on their site here:

O geez I didn’t scroll down far enough. In any event I’ve got it now.

The mailman dropped off my new SX-694 this afternoon (yeah!) and I just got it all hooked up and now building a library of darks.

One question for those of you using this camera…I noticed that when the camera is cooling there is no percentage of power being used indicated. It always stays at 0% power. Is this because the ascom driver does not report this and therefore SGP won’t show it? Or should SGP be reporting the cooler power percentage?

I can’t answer the question about power about power consumption. I’m permanently connected to mains power, so I don’t pay much attention.

The ASCOM driver on the website is the same one Harry pointed to. Bret McKee = Daddog. I’m not sure why SX doesn’t bring the ASCOM software in-house (or make Bret’s driver official), but I’ve never had any problem with it. The only thing that sticks in my head is something about on-camera vs windows shutter timing. By default, it switches over at 1 second exposure time, and they don’t work precisely the same way. So if you’re trying to calibrate your flats, you’ll see a disconnect in the exposure time:ADU ratio at one second, which can make it impossible to get proper exposure times. I set the camera to control down to 0.001 second exposures - ie, all of them. That option will pop up in the ASCOM control box. (I’m going off 18 month old memories here, so if someone sees an error, please correct it!)

BTW, I’d be very interested to know if you find yourself using darks for narrowband images. Contrary to the prevailing view that they are unnecessary, I’ve found them essential in 90% of my NB images.


Thanks for the reply Kevin. I believe the SX-694 only uses an on-camera shutter so I don’t think I’ll see the issue you described, unless I misunderstand something.

Regarding the use of darks, I simply can’t imagine not using them. The CCD can’t be perfect. We’ll see. Do you use darks for LRGB, or just for long exposure NB?

Kevin and Joel,

A little off subject. You probably read the “glow” issues from QSI 660/690 cameras from Cloudy Nights forum. Do you see any “glows” from your 30 minutes darks with your SX/Trius 694 camera? I am curious whether this is inherent to Sony ICX-XXX CCDs or camera design issue? I do not think my camera’s glows are “amp glows” because the ADU or electrons values are extremely small and barely above the rest of the image without the glows. I am still waiting for QSI’s conclusion or report after I opened the ticket.

If you have not made 30 minutes darks, I would greatly appreciate if you could capture them. Also after collecting a few 30 minutes darks, please stack them because the glows are more pronounced when stacked.


I was unaware of this. Having read through that entire CN thread I personally think that people are over-reacting. To me it’s no big deal to use darks for calibration, and since that supposedly takes care of the issue why not do it?

I agree that the glow issue is shocking when you first see it. Unfortunately my new Trius SX-694 shows the same 5 glow patterns as the QSI660. Here’s a link to an unstretched 20minx20 master dark:

BTW, I’m very new to PI and I couldn’t figure out how to save the resulting master dark after a STF auto stretch :smile: Is there a way to apply a STF and then keep the stretched image?

Also, it’s interesting to me that Bill W. in the CN thread said that his QSI660 didn’t have the glow, and also his new Trius didn’t have the glow. How could that be?

Could you point to the exact setting you are referring to in the Ascom settings dialogue?

Hi Joel,

If you read the long thread a little carefully, Bill W. initially said there was no glow in his QSI660 and later he said he made a mistake that he forget to turn on TEC and now he sees as much glows as others with TEC enabled. I have not yet seen one QSI 660/690 owner reporting without glows.



Thanks for uploading your Master Dark. Your dark does show same amount of glows as mine. It looks like it’s inherent in Sony ICX-XXX chip.

Open Histogram Transformation (HT), make sure the settings are cleared. Drag the little triangle from STF to the bottom portion of Histogram. Reset STF so that your image looks dark. Apply HT to the image. I believe it’s all there in Harry’s PI video tutorial. PI is awesome.


Ah, I didn’t see that bit about Bill W’s camera TEC. I admit, after a few pages it was hard to read that entire thread carefully.


Can you tell me the temperature you set for the 20 minutes Master Dark?


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Hi Joel,

It may not be necessary to do deep cooling for Sony CCDs since their dark current is much lower than Kodak’s CCDs. I have read that somewhere between -10C and -15C should be fine and any colder than that makes little to no difference. I set mine to -10C, this way it’s the same temperature all year long. This saves me from making many different darks of different temperature.


I wondered about that. Since I’m observatory mounted it’s not a big deal for me to create a library of darks.

Hi Joel,
Sorry for the late reply. It’s the dial for “maximum exposure seconds for hardware timer.” Dial that down as low as possible and you’ll be fine.