ASI 294MC pro, APP settings

So, did you read the warning messages properly? They explain what the issue is and it is an issue in your data, not APP. Are you using proper bias or darkflats, darks etc? And if so, do they have the same settings (bias/darkflats need the same settings as the flats, darks the same settings as the lights). Is your offset of the camera ok, check in the header that it's not at 0. It's very likely that the issue is in one of your calibration frames.

@vincent-mod

Thanks! 

Please, help me try to find what could be the value that is not good:

I'm seeing a flat exposure of 0.004 seconds, that's not right. You want to aim for about 0.5-2 seconds and getting the histogram peak (the linear one) in at least the middle or a bit further. You're probably clipping data on the darker side of the flats. Also, shooting this fast for a bias is not recommended for newer sensors. There are some issues with these sensors in that the noise is not behaving properly at fast exposures. Try to switch your bias to darkflats, which means to set the exposure of them to the same as the flats (which should be around 0.5-2 seconds).

Other than that, you can find all information in the header of your data (seen on the left of the image viewer) and try to find the offset value (which you probably also have in your capture program). This should be set to a value that's good for your sensor, but definitely not 0.

In addition to that, do you only have 4 darks and such? Ideally you want to have 30 or more darks and for bias, the same or more. This is to get a proper statistically correct master.

@vincent-mod 

Thanks! I will try with the recommended settings. An 20 -20 correction images, I just wanted to fit all of the saved images here. I just put in so little as an example.

Ok, excellent, if you tested that please come back to this post. If it worked that would be great to hear, if not, we're happy to help you further.

@vincent-mod 

Thanks!!! 

I will definitely show up, but now it will rain for at least 1 week 🙂

Hi guys!

Well, I made a flat with a longer shutter speed.
The end result has not changed, unfortunately.

I processed a batch of M51 in several ways, this time with a shutter speed of 5 minutes, not the 3 minutes as shown in the previous post.

only light images run in the APP:

then light+flat

light+flat+dark:

Light+flat+ dark+bias

did not report any errors during runtime here, although I reported working with the same files

there were error messages on previous runs

I ran several pictures over and over again, the result is always the same, whatever flat material I use, Please help me decipher what I am ruining! Thank you very much!

It does look different already, the histogram looks better so to have made these changes did do something. I think you still have an issue in your darks or bias. Would you be able to share like 20 lights, 20 darks, 20 bias/darkflats and 20 flats to us? We'll then be able to investigate further;

I uploaded. Thank you very much for your help. I wonder what he can figure out.

Sorry for the delay!

So if I look at the lights, somehow the blue channel is very much into the background. Did you use filters or something like that?

And what is the offset of your lights?

Hi! No problem. 🙂 

There is a UV / IR block filter in front of the camera. Camera offset = 8.

However, with Neutralize BG turned on, the color channels are fine, if I can see clearly.

NBG ON

NBG OFF

8 seems a bit low, I mainly see sensors more in the range of 20-30. Depends on the sensor of course.

When I check a light and then check the calibrated state, APP indeed shows that many pixels are clipping to 0. This means, likely, that your lights are underexposed, which would make sense looking at the histogram.

So what could be the solution? Push up e.g. 30 offset? And if so, only for light images or also for correction images?
My biggest problem is the rough colored circle at the edge of the picture. I'll deal with the finer settings. I’m just waiting for the APP to handle the correction images and stack. I solve the rest in PS.

The offset should be the same for all data. What APP is telling you is that the data can be improved by exposing for longer, a bit higher offset and longer exposures will likely solve the issue. APP can't apply the flats properly because the background signal is not right unfortunately. In this case it may be better to not use calibration data at all if you want to use this data. The result will be having the vignetting, but not the overcorrection at least.

Yes, I tried that. Without correction images, the image is fine, you just vignette. I should know what kind of correction images are needed for this type of camera to correct the image?

Thanks for now! If I get heaven, I'll try a higher offset setting.

Hi All!

I have come to the conclusion that my flat pictures are not good.

Can anyone tell me exactly what values should be used to take flat images with this camera,

such as APT (Astro Photography Tool {flat aid}) or ShapCap?

250/1000 Newton.

Hello,

I also have an ASI294MC Pro and got my images processed with APP without problem.
Here are my settings with my Newton 150/750:

Subs            = Gain 121, Temp -10°C, Offset 10, expo. usually 120s or 180s
90 Darks      = Gain 121, Temp -10°C, Offset 10  expo. matching the subs
11 Flats        = Gain 121, Temp -10°C, Offset 10, expo. = 4s
90 DarkFlats = Gain 121, Temp -10°C, Offset 10, expo. = 4s

Two important things:
With this camera, the flats shall be > 2s (there is a lot of threads on CN on this subject)
Don't use Biases, use Darkflats instead

Can't find any other advice.

Good luck.

...edit...
I did a quick run with APP on my data, here are some screenshots:

One Flat:

APP Master Flat:

One Calibrated Sub:

Final Stack of 35 subs:

Flats should be taken with an ADU that is at least at 50% or higher of the range your sensor can have. For a 14-bit sensor this will be at around 8500 ADU. It doesn't really matter you hit exactly that, what matters is that you're clearly away from the minimum or maximum values.

Do be careful to check if the application is also using 14-bit, many translate the 14-bit values to 16-bit. And then it would be around 35000.

Thanks!

I use this flat. Unfortunately it doesn't matter because I've tried at least 10 flats and the same result always comes out.
If I only run the APP flat, this will be the result:

if I only use dark as the correction image, the edge of the image will also be green.

I ran a friend's pictures taken with the same camera, it got flawless, So the APP works well, I hope my camera isn't faulty either, at least not based on the light pictures. I don’t know what could be wrong or what’s going wrong, but I’m already suffering a lot. 🙁

Yes, that would be ok you'd say. What about exposing for even longer, you have a quite sharp vignetting going on so maybe you still have low noise in the darks parts, could you try that? Just shift the peak to about 58000, being careful not to clip on the right side. If that doesn't work, I think I need to see the data to find out.

Thanks to everyone for their help!

It turned out that the dark images were taken with a different offset setting than the other images. 🙁
I took dark pictures with the same offset and the finished picture is perfectly fine!!! 🙂 🙂 

I’m no expert but a value of 30 offset is what is needed for the 294mc Pro. A gain of 120 is also recommended. I use a 121 on my 294 as personal preference. For your flats you need to expose from somewhere between 1- 5 seconds. Hope this helps. I use the auto flats feature in the ASI Air Pro and that sets my ADU for me. To get a 1-5 second flat I use an A3 light pad and ensure it is set to the lowest brightness when turned on. Higher brightness leads to sun second flats, which cause the same issues I’m having with your processing. 

Magic formula for the 294mc pro flats

2-5 seconds, ADU average between 25000 and 30000

NO BIAS FRAMES

Dark flats same exposure as the flats

If you go to the ASI cameras facebook page it is very well documented.

@nicholas64 do you have a link for that? I am trying to look up but not seeing it on their facebook page.