Entry level cooled CCD purchase

[uranus69]

I'm looking for a cooled entry level CCD camera principally for deep sky imaging, but with a tight budget limit of £600.

Identified the Orion Starshot G3 colour camera at £350 & the i-Nova range giving monochrome or colour options. eg NBA-M at £505.

Any feedback appreciated.   Thanks.

[cfpendock]

It's a good idea.  I would recommend mono, and to buy second-hand - e.g. Astro Buy-Sell.  You should be able to find something in your price range.

Chris

[riklaunim]

iNova are mostly "planetary" cameras, and don't have the latest sensors. Orion Starshot G3 isn't best either, especially price add-on on USA-UK logistics and taxes. If you think about a DS camera on a tight budget you must be careful not to pick something that won't be fun to use.

Your best options:

- used QHY8L - color, big sensors like in a DSLR

- use mono Atik 314E/320E - somewhat small pixels, small sensors but very low noise. Can do a lot with short focal lengths

- ASI224-COOL - incoming cooled variant of ASI224 color. It has small sensor and small pixels but you could skip the telescope and use lenses or very short APO refractors for easy imaging

- ASI174-COOL - cooled mono variant if/when the introduction prices show up may fit into your budget. Semi sized CMOS sensor with big pixels - good with most DS imaging telescopes

- miniCAM5s or miniCAM5f - mono variant, a cooled version of QHY5L-II / ASI120-alike. Small sensor with small pixels, good for lenses and short focal lengths. miniCAM5F has integrated filter wheel

[ollypenrice]

You would be likely to get hold of an older Sony 285 chipped camera at this kind of price - say an Atik 16HR - and a second hand manual filter and set of LRGB filters in 1.25 inch.

This would blow anything you could buy new so far out of the water as to send it into low Earth orbit.

Olly

[Uranium235]

Can definitely agree with that. The Sony 285 chip is legendary, but probably best served in an Atik 314L+. Its USB 2.0, and so less prone to problems than 1.0 - and it wont drag your hub down if you use one (plugging a 1.0 into a 2.0 hub drags its speed down to 1.0).

[tomato]

I was a similar situation, decided on the Sony 285 chip in a SXH-9 or Atik 314L, second hand. I ideally wanted mono and a new(ish) camera so opted for the Atik. I missed out on a mono up for sale on this forum but am now the proud owner of a 314l osc. Yes I know the mono is more sensitive etc. but extending the 'time available for imaging argument' to ' secondhand CCD cameras available for sale' at least I can now start CCD imaging if and when the skies ever clear.

[craigg]

Has anyone had any experience of the ZWO ASI224?  Particularly for long exposures/DSO.  Apparently they're about to release a cooled version.

[craigg]

Interesting - I've never heard of a cooled CMOS camera before.  I suppose there's no reason why it shouldn't work.

[riklaunim]

There are already some testers results, as well as some attempts with uncooled versions. They do work but in their unique way. If you look at ASI224 then you have to take the small pixels into account - so that many bigger telescopes will give "to high" resolution for normal/easy DS imaging. Second - those cameras take advantage of very low read noise and people take a lot of short exposed frames instead of few at X minute exposures (not always but often). Also the sensor size isn't big. ASI224 is small, ASI174 is bigger, similar to Atik 314L+.

[MartinFransson]

The Atik 314 is about 3 Mp, right? How does it fare against a 12 Mp DSLR when shooting Ha? Resolution wise, that is. The DSLR only has 1 red pixel out of 4 on the sensor so does that mean it's same same?

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[riklaunim]

Those pixels are spread on a much bigger area so you would get "holes" in such image. The best for narrowband imaging is a mono camera with as low as possible noise and as high as possible sensitivity. DSLR can't compete with that.

[MartinFransson]

I can't see any holes but I do understand that I lose resolution. Would a 3 Mp CCD interpolated to 12 Mp still have better detail/resolution?

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[riklaunim]

In Bayer filter pattern you will have 1 red pixel recording H-alpha and 3 other doing nothing - those are the holes

Don't stick to resolution that much as most nebulosity isn't that bright to be easily imaged on high resolution (or they are very big and need lower resolution to fit on most sensors). I used small 65/420 refractor with mono Atik 314L+ so small things and detail level was already high. Even at 100mm focal length from a lens Rosetta nebula had most of the detail recorded at 420mm. You can also stack frames with Drizzle algorithm to gain some extra resolution too.

[craigg]

To riklaunim's point, running the numbers through a FOV calculator, based on the ASI224 pixel size of 3.7 microns and max resolution of 1304x976, on my 200P (1000mm f5) I would get a FOV of 16.81' x 12.58' which is about 1/4 of the FOV I get with my DSLR and far too small for most DSO work - looking at Sky Safari that's just big enough to fit snugly around M51.  Good for planetary and smaller galaxies, or if I want to get up real close and personal to those star forming areas in M42, etc, but it is really quite small.  So that's got me wondering why have a cooled camera, which implies long exposures, with such a small FOV.  Again as riklaunim say, it's probably aimed at folks using a low magnification refractors in which case it may make more sense.  Maybe I'm missing the point, not sure.

Interesting discussion around the bayer matrix 'holes'.

[MartinFransson]

In Bayer filter pattern you will have 1 red pixel recording H-alpha and 3 other doing nothing - those are the holes

I understand what you mean but in reality there are no holes. The data is interpolated I guess, or only every fourth pixel is extracted, leading to a smaller image.

The resolution I am talking about is for the same given field of view. That would require different focal length for different sensors.

Take this image, for example (resized for Instagram). It was taken with a Canon 1100D and Ha-filter. If I took the same field if view with an Atik 314, would the resolution (detail) be comparable? Noise levels aside, since I know the Atik only needs a fraction of the exposure the Canon needs. My thinking is that every fourth pixel out of 12 Mp = 3 Mp and therefore comparable with the Atik 314. Or am I totally mislead?

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[riklaunim]

Yes, you can compare color to mono megapixels that way somewhat

[CSM]

I have the Orion Starshot G3 colour camera and it is possible to get some good pictures with it.  But you do need to download the latest version Orion Camera Studio software as the version on the CD is extremely ropey. 

Attached are M42 - 9x10secs captured and processed with the Orion Studio Software then edited in Elements 11 and M27 4x90secs similarly processed and edited.