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Hi All, I put together a portable rig to take to dark sites. I have bad arthritis now so I need something small and quick to setup so the FMA180 Pro is perfect for that. I am just now trying to decide on the best camera to use that would give me the most flexible options without needing multiple cameras. I have used a QHY183C with this scope and it worked well but I would like to try other options. I plan to image nebulae and galaxy clusters. I am trying to balance resolution with imaging speed so I can get all I can in 1 to 2 nights. If you own this telescope, let me know what you use. Below is a chart I put together to help with the decision process. Yes I know the 715 is pushing it LOL.  Thanks and Clear Skies! Dave |
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| I use an asi533mc pro with mine. I have been very happy with it. |
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Doug Crowe: I looked at your pictures and they look great! I have a Player One Ares-C Pro and the Askar D1 + D2 set. This looks like a good combo. Thanks! |
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| Thanks. I use the D2 filter with my L-ultimate. Works pretty good. |
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I have all of the cameras listed above except the IMX676 based camera which is used by some robotic telescopes and ZWO just released a planetary version. I have been going through my images and taking test images and I have found that the winner here that is a good balance between Etendue and resolution is the IMX183 based sensor. With such a small aperture, I have found that with larger sensors cause loss of spatial resolution in the lower wavelength frequencies. Living near Chicago that is basically one giant LED light, the blue to ultraviolet gets lost. So the 2.4um pixels recover some of this resolution in the lower wavelengths. The only issue with the camera I have which is the QHY183C, it has an IRCut window so I won't be able to use it to recover extra resolution from the near infrared that makes stars look bloated anyway. Yes the IMX533 has over double the light sampling rate but the loss in resolution is not worth it as I want to gain as much detail as possible. Also with my experiments with dithering and drizzling, I should be able to capture some impressive images that are sharp and full of detail. The average seeing for my area is actually pretty good sometimes. I can get down to as low as 0.60 arc seconds but the light pollution ruins everything which is why I am making this portable rig and selling equipment to fix up my aging van to make frequent trips to a dark site (bortle 3) about 100 miles away. Below is a graph generated from Russ's MTF Analyzer page which is a good way to help determine the best sensor to match with my optics. I have created a graph using the QHY183C, 1 arcsecond average seeing, and the approximate Oiii frequency which is harder to get. I have also included drizzling as using my technique I am actually able to recover spatial resolution which is further enhanced using deconvolution. Yes you can recover data beyond the diffraction resolution limit: https://www.rc-astro.com/mtf-analyzer/  This was an image I took last year of Andromeda using the Askar FMA180Pro with the QHY183C. I didn't dither the way I needed to recover resolution. Usually I use a spiral dither with half the sensor pixel size the way it was done with the Hubble Deep Field. I will recreate this with higher resolution and more integration time from a dark site to see how better this image can be. This was taken from my Bortle 8.5-9 location: https://www.astrobin.com/g8vri5/ |
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At the cost of some spatial resolution and FOV I could go with the IMX585 based sensor which has better quantum efficiency and NO amp glow to contend with. Also gain some light gathering from the pixel size and better quantum efficiency. Looks like the IMX533 is out as I want to get the most resolution and contrast possible from this little scope! Maybe I will go with the IMX585 instead? I guess I am going to have to do some field trials to figure this one out.  MTF IMX585  MTF IMX533  Decision, decisions :-) CS! Dave |
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FOVs... I used the Player One planetary cameras but I actually have the Ares-C Pro and the Uranus-C Pro. Both great cameras! Fitting Andromeda into the FOV of the Uranus-C Pro would be a little tight but the lower resolution would allow for me to capture a lot of frames to get some great drizzle! I am on a tight budget now thanks to the US economy and having a family to support so no more new toys for me for a while. Will also be selling some stuff to fund another project I will be working on in the future. This setup should keep me happy for a while.  |
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After all this back and forth, I am going to with @Doug Crowe suggestion which was the IMX533 or in my case the Ares-C Pro. Yeah I may be able to squeeze out more resolution with the QHY183C or Uranus-C but I realize I will be going to dark sites and I will want the biggest full well I can and highest possible dynamic range which the IMX533 is known for. Sure I can run the smaller sensors at gain 0 to utilize a larger full well but then I introduce tons of noise. The IMX533 camera I can run at gain conversion mode and still have a huge full well with way less noise. I will just make sure my dithering and drizzle are in full effect to recover any extra details. Looking at a lot of pictures on Astrobin, the 533 produces the most contrast vs the 183 and 585. I even found that our when I switched from the 585 to the 533 for my galaxy images. I am looking forward to see how Andromeda looks with the extra boost in contrast. And the large pixels will reduce the imaging as well! CS! Dave |
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Well looks like the IMX533 based Player One Ares-C Pro is indeed the winner! I had to do a 3x drizzle to recover the resolution but wow! |
