Best Mono Camera for Espirit 150 ?

[BlueAstra]

I've acquired an Esprit 150 (150mm Aperture, 1050mm Focal Length, F/7). With my current scope I use an SXV-H16 camera (2048x2048, 7.4um KAI4021M) which gives a FOV of 0.43deg and pixel FOV of 0.76". The may be a little over sampled, but I seem to get decent results. With the Esprit the SXV-H16 would give a FOV of 0.83deg and a pixel FOV of 1.45". My feeling is in this case the pixel FOV is a little high and I could do with something with smaller pixels. If so, what would be the recommendation for a reliable mono camera for use with the Esprit in the £0-£1.5k range? The SXV-H16 has been my only camera to date, doesn't seem to need darks, and I have no experience of the newer CMOS cameras.

[x6gas]

An Atik 460ex would give you a resolution of 0.89" / pixel and the 490ex a resolution of 0.72".  FoV for both is just over 40' x 30' (according to David Campbell's FoV calculator).

Both are excellent in my experience if you are looking for a CCD rather than CMOS and - while I do now take darks - both will give good results with just a bad pixel map.

HTH, Ian

[ollypenrice]

1.45"PP might be as good as your seeing usually allows. Have you tried to quantify it?

I use two cameras in the more or less comparable TEC 140, an Atik 460 for small targets and an Atik 11000 for large ones. The 11000 is way over budget though. When the seeing co-operates I find the 460 excellent for small targets like galaxies and PNs. When the seeing doesn't co-operate I either shoot colour or use the widefield rig. Something with an 8300 chip would be a good compromise and I don't subscribe to the view that the Kodak-Truesense chips have passed their sell-by dates. Although not as quiet or as sensitive as the Sony chips I actually prefer working on their data.

There is a case for CMOS, very clearly, but they do have issues which, for the moment, put me off. The main one is reflection from the chip window which can cause artefacts and stellar halos.

Olly

[gorann]

As you know one of the most popular cooled mono CMOS cameras now is ASI 1600MMpro, and it would fit your budget (even including an electronic wheel with filters). I have got one and I am so far very happy with it and Rodd @Roddhas shown some excellent images taken with it to us here at SGL. It does have some issues with microlensing creating halos around very bright stars (so I would not point mine at M45), and some are more bothered with this than others. However, it is a very quiet and sensitive camera and the cooling works great. It would give you 0.75" / pix and a FOV of 57.93' x 43.79'.

[Laurin Dave]

Hi..  I’ve used both an ASI1600 and SX-46 on my Esprit 150 (0.78 and 1.15 “/pp).  If you pixel peep the stars are clearly squarer with the SX-46 but I don’t think there’s any real detail missing.  If my seeing was better then maybe, but not from Berkshire.  The CCD data is also somewhat easier to process, less of it and much cleaner.  Another thing to consider would be whether you’re guiding is good enough to enable sub arc sec resolution.  In your situation i think I’d wait and see how my current camera performs. 

HTH

Dave

[BlueAstra]

Thank you for the comments, and any more that may appear. With my current setup (0.43deg/0.76"pix) I have tried 2x2 binning (0.43deg/1.52"pix) and noticed that the image doesn't look quite as sharp as the 1x1 image, and when you zoom in the stars look a bit more 'blocky' (technical term). That's probably subjective and I may be imagining it! So at (0.83deg/1.45"pix) I assumed I would get similar results to my 2x2 efforts, and hence a smaller pixel would beneficial. My mount is a Paramount MX and guides quite well with my SX Lodestar OAG.

Graham

 

[ollypenrice]

32 minutes ago, BlueAstra said:

Thank you for the comments, and any more that may appear. With my current setup (0.43deg/0.76"pix) I have tried 2x2 binning (0.43deg/1.52"pix) and noticed that the image doesn't look quite as sharp as the 1x1 image, and when you zoom in the stars look a bit more 'blocky' (technical term). That's probably subjective and I may be imagining it! So at (0.83deg/1.45"pix) I assumed I would get similar results to my 2x2 efforts, and hence a smaller pixel would beneficial. My mount is a Paramount MX and guides quite well with my SX Lodestar OAG.

Graham

 

I'm very surprised you see blockiness in stars at 1.5S"PP. I see none at all at 3.5"PP, at least when 'limiting' my view to 100%. I dare say they'll look blocky when scrutinized/pixel peeped at more than 100% but I don't do that. If an image is clean at 100% you're already doing well in my book. Here's an example at 100%.

Olly

 

[Laurin Dave]

Graham,  here's a comparison between  ASI1600 (3.8 micron) and SX-46 (6 micron)..  Just 1 hr of Ha on the Rosette for both and same stretch on all.  Two versions of the 6 micron,  one at native (SX-46comp2 - the last one)  and one registered to the ASI1600 data ie pseudo 3.8 micron  (the middle one), which when you pixel peep gives rounder stars. I guess you could also use Pixinsight's Drizzle to do this.   Pixinsight also tells me that the SX-46 SNR is much better.

Dave

 

[gorann]

I think I agree with Dave. Keep you camera for the time being. The ASI1600 and your current camera have simlar sized chips so no clear benefit there of one over the other. And both are far from using the real FOV of the Esprit and I and others expect (or hope) that soon an APS-C sized cooled mono CMOS camera will turn up (beta versions are being tried out). I have an APS-C sized cooled colour CMOS (ASI071) and with my Esprit 150 I have no indication of vignetting.

[steppenwolf]

I don't think I would be in too much of a hurry to change camera just yet as the one you have is pretty well matched for the typical seeing conditions that you will encounter. I'd give it a good try first and then decide if you find it lacking in the real world.