symmetal

Hi Nicola, This question was asked on the SGP forum here and runtime error 6 means the image scale (arcsecs/pixel) passed to PS2 is not accurate enough. Alan

It doesn't have to be level in any direction to enable polar alignment but having it East-West level as you have it does make drift alignment easier as there is then less interaction between azimuth and altitude adjustments. North-South doesn't matter, as you will be tilting the mount much further than this error when you adjust your altitude. If your required altitude adjustment is say 51.0 degrees, because of your error you'll have to tilt your mount by say 50.9 degrees instead. Alan

Correct. Alan

FLO has this designed for the ST80. Alan

When warming up just set the final temperature to reach to be around 5 to 10 degrees below ambient temperature. This is just to avoid a rapid large temperature change to the camera when it's unplugged which can stress the sensor. The gain can be set in the Ascom driver or in the box labelled gain on the APT Camera tab. You see the Ascom driver settings when you first select a new camera. If the camera is connected automatically and the Ascom box doesn't appear you can click on the 'Settings' button at the bottom right of the APT Camera tab. A warning box appears saying the camera may need to be temporarily disconnected from APT to make the changes. I can't remember whether this may upset camera cooling if it's on. I'll have to check. In the APT 'Settings' panel you can set whether APT is allowed to change the gain or whether only the Ascom driver can. It can be advantageous to temporarily switch to higher gain settings when focusing and this can be set to happen automatically in APT if it's allowed to do so. I'll do some screen shots later to make this clearer, as there are several places where the gain settings can be changed and it can get confusing. The 'Offset' can only be set in the Ascom driver so can't be changed in APT. There's a technical reason for this but I won't bore you with the details. For now just leave the gain at 90 (unity) as it is at the moment until you get more familiar with it. Alan

You can set the APT cooldown/warmup times in the 'Cooling Aid' and 'Warming Aid' boxes. The default is quite slow as you found. This is intended to prevent thermal stress to the sensor. 12-15 minutes is rather over cautious. It was the USB speed setting slider on the same panel I was concerned with in case you had accidently set it too high. For the moment, just check it's at 40% (fully to the left) when it appears when you first connect the camera. We'll let you play with a new scope. Can't see you getting into trouble with that. Alan

Good news Alan, I did a test with a sliced open USB2 cable and can confirm that with the 12V supply connected there is no significant USB power used on the ASI071, less than 5mA, so that shouldn't be causing any power issues. That's satisfied my suspicions as to whether the manual was correct. With the 12V removed, the USB power varies between 0.4A and 0.56A, the higher value when reading/downloading the image. This is outside the USB2 spec so the camera should always be used with the 12V supply if using USB2. I was using Firecapture for testing and I mentioned previously about setting the gain/offset in the Ascom driver setup dialog along with the USB3 speed. As you're using USB2 this speed didn't matter. However, it's not labelled USB3 speed, just USB speed, and it is relevant to USB2. I had to set it to 60% or less for the camera to work reliably in Firecapture. Above 70% it failed to capture/download images. So it's worth checking this value Alan, and perhaps setting it at its minimum of 40% until you're happy that everything is working well. Hopefully your frustrating session yesterday was as you think, just due to the wrong camera selected in PHD2. Good luck. Alan

A powered hub would be worth trying. They are pretty cheap. As this all started with the 071 just using a powered hub to connect to the the 071 is worth trying. I'm not convinced that that the 071 is powered from the 12V despite what the manual says. I'll chop up a USB2 lead to measure it just to settle my own curiosity. Alan

The spec required for running those things is not high and your laptop is more than enough. It does look like a USB power issue. Do you have a powered external USB hub or is everything plugged into the laptop. I assume when you used your DSLR instead of the 071 the setup was the same and there were no problems. Alan

Glad to hear it is now all working with APT. I found with mine that 30 degrees is the most it can cool. Hope there's no more thoughts of sending the camera back. Alan

I have the latest version. With the 071 connected the cooling option does appear so that's fine. There's no black level slider under the gain. The 'Brightness' setting under 'Image Controls' does go from 0 to 80 so it looks like it may be the same as 'Offset'. If it is it should be under 'Camera Controls'. The gain goes up to 600 while the Zwo 071 driver gain goes to 240. If I use the Ascom driver the 'Brightness' setting disappears so it is most probably 'Offset'. Eventually found dithering under live stacking. Live stacking is handy for EEVA but isn't used for normal DSO imaging. While you can tick 'Save Individual Frames', everything is really concerned with the stacking, so really 99% of the features available aren't used. I'm sure you can do standard long exposure imaging, but the program is not tailored for this which is why Alan found it difficult to work with. I'm not knocking the program, what it does it does well with good features but it's main purpose isn't 'standard' DSO imaging. Alan

Hi Alan, Following on from my previous post I installed APT and the ZWO drivers along with ASCOM itself (forgot about that ) on my Laptop with USB2 ports and it all performed with no problems. Without the 12V supply it took long exposures OK and with the 12V connected cooled it by 20 degrees using the default APT cooling aid settings, took a couple of 1 min exposures and warmed it back up. Also the Ascom camera selection didn't play up like it does on at least two of my other PCs. Maybe I need to reinstall Ascom on them. Although a USB2 socket should supply up to 0.5A this may not be true in all laptops where they have possibly skimped on the power. In order to confirm that the camera uses the 12V when it's connected and not the USB power, I'll have to cut open a USB2 cable and cut the power wire to insert an ammeter to measure it. I'm happy to do that as I have plenty of old USB2 cables lying around doing nothing. See how your test goes when you try it indoors tomorrow. Alan

Hi Alan, I just tried my 071 with APT and it worked with no problems. I also tried using a USB2 cable instead of USB3 and it still worked. When you first connect the camera you need to select CCD: ASCOM camera. The Zwo native drivers don't appear in the drop down box. When you click OK and the ASCOM camera chooser dialog appears. Choose ASI Camera 1 and then the 'Properties' button. Choose the ASI 071 camera (if you have more than one camera connected) and here you can select the gain/offset (choose unity gain from the drop down menu) and whether you want the anti-dew heater to be on. If you are in humid conditions it's worth having it on but for now can be left off. Then click OK and APT will say 'Camera Connected'. I tried a few long exposures with no problems. There is a kind of bug in the Ascom camera selector screen. When the Ascom Camera chooser box appears select the camera fairly quickly and then the camera options and the OK. I've found that taking more than a couple of seconds to choose the camera it may crash requiring a restart of APT. Also if you click away from the camera selection window to another program or window before you've made the selection and options and clicked OK on the ASCOM dialog, it will almost certainly crash the program. This is not an APT problem as it happens the same if I use FireCapture for planetary imaging. It happens with other cameras and not just the 071. SGP which I normally use for imaging seems more tolerant of this ASCOM chooser dialog as it normally doesn't cause a problem. If it's the only camera connected after the first time of setting up it will automatically connect without the Ascom chooser box appearing. Edit: As my USB2 cable is plugged into the PC USB3 socket it is able to supply 1A to the camera so wouldn't cause a power problem if the 12V power supply isn't used to power the camera as it says it does. I can install the drivers on my USB2 laptop and try the camera there with and without the 12V supply so see if there is any issue. I'll report back. Here's a screen shot with the camera connected, cooled and then warmed and a 60s exposure taken. No errors Alan

I checked out Sharpcap and it is intended for video imaging for planets, moon etc. using many short exposures and is not really suitable for long exposure imaging. Dithering isn't used for planetary imaging so wouldn't be a feature. The default file capture format is AVI (a video format) means its intended use is planetary imaging. It has a very good polar alignment tool, useful for setting up your mount for long exposure imaging, but good polar alignment isn't a requirement for video imaging. Sharpcap doesn't support camera cooling either on first glance, as for planetary imaging that isn't important. Taking a thousand extra video frames to stack would remove the extra noise due to not being cooled. I would just use Sharpcap for polar alignment if you wish, and then use APT for your long exposure imaging as you're familar with that from your DSLR imaging, and there's really little difference between DSLR and astro camera imaging in that respect. You have dithering available and set point cooling with APT. Also, proper gain and offset settings can be set in the Ascom driver using APT. The gain setting in Sharpcap does correspond to the Zwo gain settings I believe, but the offset setting is called 'brightness' under Image Controls section and the numbers don't correspond to the actual Zwo offset settings, but are arbitrary values used looking at the histogram to avoid black clipping. Alan

No I wasn't suggesting you to use USB3, just to use USB2 cables that are a good fit in the camera USB3 connector as a wobbly connector can cause problems. Alan

That length cable should be fine. Just be sure it's a firm connection in the camera and doesn't easily wobble about. A bonus with USB3 is that the cables are a more snug fit compared to USB2. That's the reason I swapped my USB2 cables for the Lindy Chromo cables (as FLO now stock). They look nice but the snug fit is the bonus. Alan

Good. That's progress. I was wondering, as you're using USB2 what length cable are you using, and do you have any USB extender cables in the connection to the camera. As the USB2 connection will be trying to work at its maximum speed, extenders or a cable over 5m can cause intermittant communication problems when working at high speed, which could lead to the type of problems you had initially. Alan

That's what the other ASI cameras state which have a 12V cooler supply. But the manual for the 071 at the end of the 'Power Consumption' section states 'ASI071 and USB hub is powered from the 12V DC power supply if you connect it.' Whether that's true or not remains to be tested. Alan

That's a pity. The manual says that the camera draws 0.5A (without cooling) which is the limit for USB2 and is why they recommend USB3 which can deliver 1A. However it also says if the 12V power is connected to power the cooler the camera will use that instead of the USB power so that should be OK for you. You do have the 12V connected I presume and your USB2 cable is plugged into the USB3 connector on the camera and not the USB2 sockets. As it does nothing apart from recognising the camera does imply a power problem somewhere. Also look in 'Device manager' on your PC and check if the camera is there under 'Imaging Devices' and has no yellow exclamation mark next to it which would imply a driver problem. Alan

APT is a very reasonably priced program for imaging too which many people here rate highly too. I assumed Sharpcap was more geared towards planetary video imaging though I'm willing to be proved wrong. The small printed manual included with my 071 was actually the manual for the 1600 which does show a 1.25" filter thread on the rear of the 1.25" nosepiece adapter which may have confused FLO. The actual 071 manual downloaded from the Zwo website just mentions 2" filters which are M48 threaded in reality. Alan

Mine's the same. The only solution is using an ND filter which isn't easy to incorporate. It would be handy if there was an ND dome which can sit over the existing one. I have mine covered up during the day just to avoid the possibility of the Sun damaging the sensor, although SX said they have no experience of this being a problem. Alan

Good to hear. Your wider angle lens on the Oculus gives a more pleasing image compared to mine which has the narrower angle and crops the circle top and bottom. i know it doesn't use as much of the sensor area, but I think I'll buy the wider angle lens and give it a go. Can't imagine they cost much. Alan

You need to install the C++ redistributeable package for Starlight Xpress cameras. I had the same problem mentioned further up the thread. The download link is on the 'Requirements' page of the AllSkeye website. Alan

Wow! I wonder what that's like. I think the most clear nights I've had in a row is about three. Alan

I would just start with the unity gain setting as selected in the Ascom driver, gain 90, offset 65. The offset looks fine for all gain settings (no black clipping) so there's no need to change that. I've only had my camera for about a month and haven't been able to take any real images with it, just a few tests so can't recommend a starting exposure at the moment. Others who've had the camera for longer can give more practical advice there. For my 1600 I found 180s was optimum for RGB so that the sky background level swamped the read noise. It depends on your level of light pollution as to what the optimum is. I was going to start with 180s with the 071 (assuming the Star Adventurer can manage that without star trails) but may have to limit it to 120s. I may have to mount it on my AZ-EQ6 if I need longer exposures. Others advocate using half unity gain (gain 30 for the 071) for RGB and twice unity (gain 150 for the 071) for narrowband imaging, but this means having to take a set of darks for each gain setting so I stick with unity gain. If you're interested the sky background ADU (16 bit) to swamp the read noise (where the sky b/g is ten times the square of the read noise) is 526 for the 071 at unity gain and offset 65 but that may be more than you want to know. The other setting in the driver is USB3 speed limit. If you have a fast enough imaging PC you can set it at 100% to get the shortest download time but if you experience problems with corrupt or missing images you will need to set it to a lower speed limit. Alan