Atik Apx60

[symmetal]

1 hour ago, gorann said:

I assume that the ATIK camera has a similar circuit to that of the ASI, which at a certain gain (100 for ASI2600) gives a magical drop in read out noise (making most users use gain 100). However, I could not see any details on this in the ATIK manual.

Yes, I'm surprised that the Atik manual gives no graphs at all. If it has an HCG mode I'd have thought the manual would have mentioned it. 🤔 The Zwo ASI6200 graphs are almost identical to the ASI2600 graphs apart from the read noise being almost constant above Zwo gain 100, implying there's no real point in exceeding gain 100. In fact the Zwo driver only allows gain settings from 0 to 100

The Zwo ascom driver has the USB speed setting if needed to get reliable downloads. I notice the Atik has gain settings from 0 to 36 and offset 0-4095. This implies the Atik gain is in dB steps while the Zwo gain is in 0.1dB steps. Also the Atik offset is likely in steps of 1 ADU (at 16 bit) while the Zwo offset goes from 0 to 200 and is in steps of 10 ADU (16 bit).

There's no mention of an anti-dew heated front window in the Atik manual either. 🤔

Another difference is in the Dark Current. Atik quotes 0.03 e-/pix/sec at -10C

This is the Zwo dark current graph

Here 0.03 dark current is at 20C and at -10C has a dark current of around 0.00098 e-/s/pix.

e-/secs/pixel and e-/pixels/sec are the same thing I would have thought. Here's the above graph plotted linearly.

and the bottom section expanded

Alan

Edited May 21, 2022 by symmetal

[Tom OD]

15 hours ago, symmetal said:

There's no mention of an anti-dew heated front window in the Atik manual either. 🤔

I don’t even think there ever was one. It used to be a firmware change that you installed and you could set the power by setting the percentage I think. It was so long ago I can’t remember. However I don’t think it ever showed up as on anywhere in the software. 

[gorann]

7 hours ago, Tom OD said:

I don’t even think there ever was one. It used to be a firmware change that you installed and you could set the power by setting the percentage I think. It was so long ago I can’t remember. However I don’t think it ever showed up as on anywhere in the software. 

I assume the ATIK has a HCG mode like the ZWO and QHY versions to bring down read noise and it must have a front window dew heater, but it is odd that I see nothing about any of this on the ATIK site or in the manual.

[symmetal]

A quick check to see that the HCG mode is enabled in your Atik Tom is to take 2 bias frames, one without HCG and one with and look at the results in Fits Liberator or similar fits viewing program. On the ASI6200 HCG is enabled at gain 100 and above. Here are my results below for gain 100 and gain 99, (HCG disabled) Note the difference between min and max ADU values and the Standard Deviation. HCG on, SD is 6.0, HCG off, SD is 12.9. This is at room temperature too.

As your gain settings appear to be in steps of 1dB, I suspect it will be enabled at gain 10 on the Atik, assuming it is automatically enabled on the Sony sensor chip rather than being set by the controlling software. You can take test bias frames at say gain 0, 5, 10, 15, 20 etc and see where the read noise decreases sharply, ie the SD drops noticeably. That's where the HCG mode kicks in. That's the gain setting I would use all the time. 🙂

Also, you can see if your offset is good too while looking at the bias frames. The minimum ADU value must be significantly above 0 to avoid black clipping. It's 368 ADU on mine at gain 100. My offset setting is 50, with an offset increase of 1 increasing the output ADU by 10. Offset 50 therefore adds 500 ADU to the output which you'll note is where the peak of the bias histogram is, also corresponding to the image mean or median value. If the offset was 0 then the peak of the bias histogram would be around zero too and the left half of the histogram would be clipped to black, which is bad. I could get away with offset 30 without clipping, but I left it at the default 50. The tiny loss of dynamic range due to the offset being too high is insignificant.

As your offset is in ADU steps of 1 rather than 10, I would start with offset 500 and see what the bias looks like. Aiming for a minimum image ADU of at least 200 to 250 should be fine. Note that as the gain is increased the offset may need increasing too to avoid black clipping, but you'll most likely only use the camera at the one gain setting where HCG is enabled. 🙂

Alan

[Tom OD]

19 hours ago, symmetal said:

A quick check to see that the HCG mode is enabled in your Atik Tom is to take 2 bias frames, one without HCG and one with and look at the results in Fits Liberator or similar fits viewing program. On the ASI6200 HCG is enabled at gain 100 and above. Here are my results below for gain 100 and gain 99, (HCG disabled) Note the difference between min and max ADU values and the Standard Deviation. HCG on, SD is 6.0, HCG off, SD is 12.9. This is at room temperature too.

As your gain settings appear to be in steps of 1dB, I suspect it will be enabled at gain 10 on the Atik, assuming it is automatically enabled on the Sony sensor chip rather than being set by the controlling software. You can take test bias frames at say gain 0, 5, 10, 15, 20 etc and see where the read noise decreases sharply, ie the SD drops noticeably. That's where the HCG mode kicks in. That's the gain setting I would use all the time. 🙂

Also, you can see if your offset is good too while looking at the bias frames. The minimum ADU value must be significantly above 0 to avoid black clipping. It's 368 ADU on mine at gain 100. My offset setting is 50, with an offset increase of 1 increasing the output ADU by 10. Offset 50 therefore adds 500 ADU to the output which you'll note is where the peak of the bias histogram is, also corresponding to the image mean or median value. If the offset was 0 then the peak of the bias histogram would be around zero too and the left half of the histogram would be clipped to black, which is bad. I could get away with offset 30 without clipping, but I left it at the default 50. The tiny loss of dynamic range due to the offset being too high is insignificant.

As your offset is in ADU steps of 1 rather than 10, I would start with offset 500 and see what the bias looks like. Aiming for a minimum image ADU of at least 200 to 250 should be fine. Note that as the gain is increased the offset may need increasing too to avoid black clipping, but you'll most likely only use the camera at the one gain setting where HCG is enabled. 🙂

Alan

Thanks for all these great ideas. I'll do these tetss and post my results.

Thanks Again Tom

[Adam J]

On 22/05/2022 at 23:09, gorann said:

I assume the ATIK has a HCG mode like the ZWO and QHY versions to bring down read noise and it must have a front window dew heater, but it is odd that I see nothing about any of this on the ATIK site or in the manual.

I believe that ATIK tend to use a quartz fused cover glass / window in place of a dew heater on most of their products. 

Edited May 24, 2022 by Adam J

[Tom OD]

Ok well attempt one has sort of failed.

I did manage to get the camera to connect in SGP, but it failed to save any Bias frames.

So I went to Dusk which I downloaded, and it wouldnt connect to the camera.

Third go was getting Artemis to connect, and it did. In the exposure settings there are the settings that match what SPG and the download manual sees.

However it hung flushing a frame and I had to quit the program. So no bias frames were downloaded.

At that point sitting in the idling car the battery on the laptop started to fail.

Very odd behaviour all around. I really need a 220v AC adapter that can give 5amps to test this properly. Disappointing that this was not supplied with the camera really.

Anyway at least the Artemis and SGP has the settings visible and changes can be made to them.

Tom

Edited May 24, 2022 by Tom OD

[symmetal]

That's disappointing Tom.  Without the camera cooler running the power consumption is less than 1A and the ASI can be powered just from the USB3 connection, though a laptop may not supply enough current via USB3. I assume you were using the cigarette connector too. It does look like a power issue though as USB speed issues only arise while downloading and you have difficulty connecting.  My mini-PC on the scope will often hang downloading if the USB3 speed setting on the ascom driver is at 100%. I have it set to 75% and have no issues. You don't  seem to have that option though so that must be set automatically on connecting.

The Atik has a standard 2.1mm centre positive connector so any generic 12V power supply you have supplying 2A or more would work for testing if you don't have the cooler running.

Alan

[gorann]

With my ASI 2600MC, things stop working if I failed to connect the 12 V power (so USB is not enough). Have not tried my ASI 6200MM without 12 V but I expect it would be the same. So all power need to be connected.

Edited May 24, 2022 by gorann

[tomato]

Same here, my QHY268c won’t work if there is no 12V supply connected.

[Tom OD]

21 hours ago, symmetal said:

That's disappointing Tom.  Without the camera cooler running the power consumption is less than 1A and the ASI can be powered just from the USB3 connection, though a laptop may not supply enough current via USB3. I assume you were using the cigarette connector too. It does look like a power issue though as USB speed issues only arise while downloading and you have difficulty connecting.  My mini-PC on the scope will often hang downloading if the USB3 speed setting on the ascom driver is at 100%. I have it set to 75% and have no issues. You don't  seem to have that option though so that must be set automatically on connecting.

The Atik has a standard 2.1mm centre positive connector so any generic 12V power supply you have supplying 2A or more would work for testing if you don't have the cooler running.

Alan

I had the cooler running to -15c from the car cigarette lighter port. It did download a few 300s the very first time I tried the camera. 
so can’t say for sure what hung the software on this second attempt. I d rather test with the cooler running to get done graphs so I just may have to go get a 5amp rated 12v mains power supply as it could be a while before I get out to the observatory. I d like to be a little bit familiar so I can run it remotely once I get home. 
Tom. 

Edited May 25, 2022 by Tom OD

[Adam J]

On 24/05/2022 at 22:12, gorann said:

With my ASI 2600MC, things stop working if I failed to connect the 12 V power (so USB is not enough). Have not tried my ASI 6200MM without 12 V but I expect it would be the same. So all power need to be connected.

Some smaller sensors power from usb only but the bigger sensors don't. 

[Tom OD]

On 23/05/2022 at 01:25, symmetal said:

A quick check to see that the HCG mode is enabled in your Atik Tom is to take 2 bias frames, one without HCG and one with and look at the results in Fits Liberator or similar fits viewing program. On the ASI6200 HCG is enabled at gain 100 and above. Here are my results below for gain 100 and gain 99, (HCG disabled) Note the difference between min and max ADU values and the Standard Deviation. HCG on, SD is 6.0, HCG off, SD is 12.9. This is at room temperature too.

As your gain settings appear to be in steps of 1dB, I suspect it will be enabled at gain 10 on the Atik, assuming it is automatically enabled on the Sony sensor chip rather than being set by the controlling software. You can take test bias frames at say gain 0, 5, 10, 15, 20 etc and see where the read noise decreases sharply, ie the SD drops noticeably. That's where the HCG mode kicks in. That's the gain setting I would use all the time. 🙂

Also, you can see if your offset is good too while looking at the bias frames. The minimum ADU value must be significantly above 0 to avoid black clipping. It's 368 ADU on mine at gain 100. My offset setting is 50, with an offset increase of 1 increasing the output ADU by 10. Offset 50 therefore adds 500 ADU to the output which you'll note is where the peak of the bias histogram is, also corresponding to the image mean or median value. If the offset was 0 then the peak of the bias histogram would be around zero too and the left half of the histogram would be clipped to black, which is bad. I could get away with offset 30 without clipping, but I left it at the default 50. The tiny loss of dynamic range due to the offset being too high is insignificant.

As your offset is in ADU steps of 1 rather than 10, I would start with offset 500 and see what the bias looks like. Aiming for a minimum image ADU of at least 200 to 250 should be fine. Note that as the gain is increased the offset may need increasing too to avoid black clipping, but you'll most likely only use the camera at the one gain setting where HCG is enabled. 🙂

Alan

I managed to borrow a 12v mains power supply that gave 2.5A Not quite the 5A needed to use the full cooler. So instead I put the camera in the fridge, where the sensor thought it was 11C. It was in there for over an hour and cold to the touch. I would have thought it would have been 5C approx.

Anyway here are the Bias results using Noise Evaluation script in PixInsight and Statistics in AstroArt6

So first thing to note is the difference in both programs seeing the noise at different Gain settings. If you assume Standard Dev = Noise from the two programs.

Once you increase the Offset, which I guess gives a better result on the data, as no black clipped data is rejected then the 30 / 35 Gain seems to show the lowest Noise in PI (One cell is incorrectly marked Blue as the lowest in the image offset 1000 gain 30), but 0 Gain is the best in AstroArt6

So very confusing, I m none the wiser which would be best. Especially given that the Atik manual suggests dont go over 30 on the gain.

From the data the AstroArt6 Standard Deviation is a straight increase line.

The Noise script gives an "M" shape for all 3 offset data sets.. So I dont know about HCG on this camera.

Anyone want to give an input to the data?

Thanks Tom

 

[symmetal]

Hi Tom,

From your results there is no indication than HCG mode has been enabled at any gain setting. The noise SD just increases with gain just like with a camera without HCG. HCG is built into the sensor though I expect there is an option to enable/disable it via software. I think it's worth dropping an email to Atik to query this as this is a major selling point of cameras with HCG sensors.

However, your SD figures are similar to what I have at gain 100 (your gain 10) when HCG is enabled on the ASI, which may imply that HCG is enabled all the time on the Atik. 🤔 At room temp I have SD 5.9 with HCG on and SD 12.9 with HCG off.

Regarding offset I would think that 500 is a reasonable figure which would give you ADU minimums of around 350, though offset 400 would be OK too if you wish.

Alan

Edited May 30, 2022 by symmetal

[Tom OD]

19 minutes ago, symmetal said:

Hi Tom,

From your results there is no indication than HCG mode has been enabled at any gain setting. The noise SD just increases with gain just like with a camera without HCG. HCG is built into the sensor though I expect there is an option to enable/disable it via software. I think it's worth dropping an email to Atik to query this as this is a major selling point of cameras with HCG sensors.

However, your SD figures are similar to what I have at gain 100 (your gain 10) when HCG is enabled on the ASI, which may imply that HCG is enabled all the time on the Atik. 🤔 At room temp I have SD 5.9 with HCG on and SD 12.9 with HCG off.

Regarding offset I would think that 500 is a reasonable figure which would give you ADU minimums of around 350, though offset 400 would be OK too if you wish.

Alan

Thanks for your reply Alan. I'll mail Atik and see what they say. It would be good to know exactly what their presets do to the camera. Its hardly an Intellectual Property thing?!

I certainly didnt get anywhere near your 12 SD values, so as you say maybe it was always On, or On from my "Power Save" selection.

Yes my 1000 is way to high on offset I think. I'll drop that by at least half.

Tom

[Tom OD]

46 minutes ago, symmetal said:

Hi Tom,

From your results there is no indication than HCG mode has been enabled at any gain setting. The noise SD just increases with gain just like with a camera without HCG. HCG is built into the sensor though I expect there is an option to enable/disable it via software. I think it's worth dropping an email to Atik to query this as this is a major selling point of cameras with HCG sensors.

However, your SD figures are similar to what I have at gain 100 (your gain 10) when HCG is enabled on the ASI, which may imply that HCG is enabled all the time on the Atik. 🤔 At room temp I have SD 5.9 with HCG on and SD 12.9 with HCG off.

Regarding offset I would think that 500 is a reasonable figure which would give you ADU minimums of around 350, though offset 400 would be OK too if you wish.

Alan

Maybe this is the HCG equivalent?

I had it set in the capture program for the test shots.

[symmetal]

4 minutes ago, Tom OD said:

Maybe this is the HCG equivalent?

Possibly. It's worth doing the tests in normal mode and see what the SD figures are for comparison.

Alan

[Tom OD]

10 minutes ago, symmetal said:

Possibly. It's worth doing the tests in normal mode and see what the SD figures are for comparison.

Alan

Yes I should that with all the settings and see. I'll wait for Atik to reply first I think. The fridge is now full of food

 

[symmetal]

Just now, Tom OD said:

The fridge is now full of food

You can do it at room temperature just for the test. Just try gain 0, 10, 20 at offset 500 with the different power modes.

Alan

[Tom OD]

Here are some more results from todays tests. Taken at room temp, and an offset at 400 for the table of varying Gain values.

Then I tried different "Power" modes. The Power Save is not the lowest noise / SD value as the manual states.

All in all I think it might be best to just go with the Power Save mode, and Low settings that Atik set.

There is no obvious HCG cliff in the data as in the ZWO settings.

Tom

 

 

[symmetal]

Yes there seems little real difference in the noise in the three power modes.

I'm not sure what the LOW, MEDIUM and HIGH settings refers to as Medium and High show a large min to max change with black clipping present. Power Save Medium and High show black and white clipping too.

I'll be interesting to hear what Atik say concerning the HCG setting.

Alan

Edit: It looks like Low, Med, High are possibly preset gain/offset settings with Low being gain 0 as the SD figures agree with your SD table. Med and High show much higher SD values than your SD table on the right. I'd have thought the SD would be significantly higher at higher gain settings than your right SD table shows, so not sure if the higher gain values are being set correctly when entered manually.

The preset offset value of 200 is a bit low at LOW setting though is just avoiding black clipping.  At MEDIUM and HIGH the preset offset is too low but in Power Save mode it white clips anyway so no offset value entered here would be much good. 🤔 Does it display what the actual gain settings are when you preset MEDIUM and HIGH.

Edited May 31, 2022 by symmetal

[Tom OD]

1 hour ago, symmetal said:

Yes there seems little real difference in the noise in the three power modes.

I'm not sure what the LOW, MEDIUM and HIGH settings refers to as Medium and High show a large min to max change with black clipping present. Power Save Medium and High show black and white clipping too.

I'll be interesting to hear what Atik say concerning the HCG setting.

Alan

Edit: It looks like Low, Med, High are possibly preset gain/offset settings with Low being gain 0 as the SD figures agree with your SD table. Med and High show much higher SD values than your SD table on the right. I'd have thought the SD would be significantly higher at higher gain settings than your right SD table shows, so not sure if the higher gain values are being set correctly when entered manually.

The preset offset value of 200 is a bit low at LOW setting though is just avoiding black clipping.  At MEDIUM and HIGH the preset offset is too low but in Power Save mode it white clips anyway so no offset value entered here would be much good. 🤔 Does it display what the actual gain settings are when you preset MEDIUM and HIGH.

No there is no mention of what the gain and offset values are actually running at in the preset modes Low Medium High. However given the Background values that match the closely the ADU, it looks like they run at 200, 400, 1050.

So maybe as the manual says, the Power save, Normal and Fast which show very little differences are like the USB speed in your ZWO menu. I can see how Fast would allow lots of frames to downloading to beat the seeing.

I m at a loss to explain the Medium and High Presets though. Looking at the Medium and High frames though, the 0 ADU seems to correspond to the lower x axis, yet the offset appears to be at the 400 / 1000 mark.

I guess either the gain is maxed out, and / or internally the s/w is doing something to the chip causing the data to get clipped on the Min values. Very confusing.

See attached Stats FOV from the Medium Preset setting on Normal Mode.

Tom.

Edited May 31, 2022 by Tom OD
I read the manual incorrectly.

[symmetal]

The SD values on MED and HIGH are fairly similar but both way higher than on LOW. As these don't match the SD values at higher gain when set manually, which as I mentioned before seem too low at the higher gain settings, it's a bit of a mystery.

It looks like the preset LOW setting is the only preset to use for DSO imaging. It would be useful to test the manual gain settings using a flats panel or similar, to see if the manual gain settings do work as you would think. At gain 6 you should get a signal gain of x2 compared to gain setting 0, so your flats ADU peak value should double. Likewise gain 12 should give a x4 signal gain over gain 0. Gain 30 is a x32 signal gain.

Alan

[symmetal]

1 hour ago, Tom OD said:

I m at a loss to explain the Medium and High Presets though. Looking at the Medium and High frames though, the 0 ADU seems to correspond to the lower x axis, yet the offset appears to be at the 400 / 1000 mark.

As the camera gain increases the noise range from min to max will increase as well, likewise the SD. You therefore need to increase the offset to ensure the min value stays above 0. Your Medium and High presets both seem to have a very high gain setting so even with the higher offset applied it's not enough to avoid the black clipping.

The power settings could be USB speed settings as you say. The Atik manual doesn't mention whether ROIs can be set for planetary imaging. Without a ROI the frame rate will be very low on such a large sensor.

Alan

[Tom OD]

1 hour ago, symmetal said:

As the camera gain increases the noise range from min to max will increase as well, likewise the SD. You therefore need to increase the offset to ensure the min value stays above 0. Your Medium and High presets both seem to have a very high gain setting so even with the higher offset applied it's not enough to avoid the black clipping.

The power settings could be USB speed settings as you say. The Atik manual doesn't mention whether ROIs can be set for planetary imaging. Without a ROI the frame rate will be very low on such a large sensor.

Alan

Yes a full frame planetary camera seems counter intuitive.

Increasing the offset to stop clipping makes sense as I read it.

Thanks for all your inputs here.

I think its lead me to the Low setting, and Power save. That suggests that it'll also keep the full well depth high. Unless I m chasing super dim nebula, I wont change those settings.

Tom