Help choosing a dedicated astro camera.

[blackparticle]

Even though it has served me well so far, I know the Pentax I'm using isn't really up to the job for deep astro imaging. Now I've got a NEQ6, I think it's time to start looking at the options available and relegate the Pentax to doing wide-field shots with 50mm and under lenses.

Part of the problem I have had is in the dark-frame subtraction from the camera. No matter what I've tried, the dark frames haven't really dealt with the amp glow and colour gradiation across the image. The only real success I've had is to leave the cameras "auto-dark" noise reduction on which works admirably. Unfortunately this has been at the expense of valuable imaging time and many wasted photons.

Because of this, I'm somewhat reluctant to continue down the DSLR route and would prefer a dedicated astro cam.

What I do like about the DSLR is the massive 10MP APS-C sensor size although I do find myself having to crop part of the frame to remove edge of field distortion and then to reduce the image massively for screen display. I would still like to have large images for printing purposes although I concede a smaller sensor would be more suitable for my scopes.

Even though I've got a manual Atik filter wheel (bought as a bargain for future use), I'm thinking I might stick with OSC for now unless there is an obvious monochrome camera which I should be considering.

So, based on that my criteria are -

1. 2Mp+ (1600 x 1200-ish minimum)

2. Set-point cooling or at least cooling of approx 15deg below ambient.

3. 16 bit.

4. 15fps ROI video mode if possible.

I've not really set myself a budget but for my first dedicated astro-cam I'd like to keep it roughly on par with what a dedicated astro-DSLR would cost.

At the top end of the scale I've looked at the Atik 320E although I've read that, even though it's an adequate camera, it's overpriced for what it is when compared to the 314.

Then there is the QHY8L?

I've also noticed an Opticstar DS-335C ICE on ABaS although the pixel size is tiny.. which may or may not work in my favour. I suppose it depends on what I am imaging? I don't see many people listing Opticstar in their eqpt lists though.

So, any other suggestions to help me through this minefield?

Cheers, Alan.

[blackparticle]

I take the lack of response indicates that either I should have posted this in the eqpt section or that there really isn't a worthwhile alternative to a modded DSLR at this price point.

It has just occurred to me though that with OSC, I am effectively halving the detail due to the bayer matrix when compared to a mono cam.

With that in mind and the fact that I already have the filter wheel.. should I just spend the extra, get an Atik 314L+ and stop thinking about it?

Maybe I've just answered my own question.

[NickK]

I think you'll be disappointed by attempting to go for fps and good stills.

If you want speed then the sony sensors without a shutter are going to give you a better fps. The sony sensors are more sensitive too with less noise, only down side is their small size. The 314L+ is very good from what people have shown..

I've just got myself a 383L+ and I would say it's a very capable camera (big 8MP, set point cooling) however I would suggest a minimum of 1 second frames due to the shutter and the size of the data being read from the camera (even over USB2) to be honest so it's not going to give you the fps side of things.

[ollypenrice]

You don't lose much resolution with OSC. This is a myth. The software interpolates a synthetic luminance layer which is pretty effective. I did a careful shootout on M42 for Astronomy Now a couple of years ago and my Iris, now in the DS section, was shot half and half, RGB only (no lum) in the mono and half in the OSC. This time the OSC was slightly better for some reason but sometimes it's the reverse.

But I'd go for mono. More consistent, more flexible and way ahead for narrowband.

And I'd go for the 314L. QHYs get far more discussion on how to sort out this or that issue than Atiks, which rarely get any at all. I have five in very heavy use and find them reliable.

Olly

[whirlpool5194]

Sxvh9, Atik 314, Atik 16hr or Artemis 285 would make an excellent starter ccd...

Wp

[blinky]

I have a QHY8, no problems with it - you wont find a better value 8mp CCD than the QHY...

[antimorris]

My vote is for the 314L as well - I have the mono one and absolutely love it.

[cgarry]

My vote is for the QHY8L. Very similar chip size to a DSLR, but with 16-bit resolution, better sensitivity and far less noise. Like a DSLR on steroids!

Chris

[riklaunim]

For DS imaging you need the DS camera (16 bit) and a guider. For fast planetary/Lunar (8/12 bit) - planetary camera (which also may be a guider). So just get for DS either mono Atik 314L+ or color big QHY8 + a guider that is also very good as solar system imaging.

[blackparticle]

I've seen good results with the Atik 314L+. A few of the guys up at NLO are using them so I know just how sensitive they are as I've been watching the live-views as the subs roll in. Very impressive.

Based on price / performance ratio for a mono I think that's currently the leading contender and I believe Atik will be introducing Mac capability later in the year which is certainly another plus as that would let me remote-control the setup from indoors or on an Ipad.

The 15fps video mode would have been a bonus but I'm not going to let the lack of on the Atik put me off. It will do fast "shutter" times (although it doesn't have a mechanical shutter does it?) so should at least double up as a powerful single-frame lunar cam. No good for planets though with the 1.8s image download time.

Well.. I think that's settled it.

Cheers for the suggestions.

[antimorris]

You can use it with a Mac already, just not with Artemis Capture ... I use it with Nebulosity on my MacBook Pro - its great

[blackparticle]

Really?! I didn't know that.

I have Neb2.. Does it support the TEC set-point cooling system as well?

[antimorris]

Yes, though it isn't as intuitive to set as Capture ... if you go to Nebulosity->Preferences you can then set the TEC cooling point on the bottom line of the first section.

[NickK]

From experience, Nebulosity's TEC option is a bit hit and miss as it doesn't seem to work on my 383 - and it's probably down to the preferences...

[blackparticle]

I'm not too concerned with what I use to capture with after getting the cheap laptop as long as it works. My Macs do other things as well. Mostly music related stuff and they are mission critical to me for that so I'd probably get slightly paranoid leaving them outside (although almost every icon on my desktop on this one is now astro-related. ).

I do remember Davy at NLO explaining the TEC on the Atiks and he mentioned that there is a warm-up function in the software which really should be used before turning it off to prevent damage. I take it that is part of the software that comes with them?

[antimorris]

Yes, Capture has the warm-up button down with the turning the TEC on. (For the record, I do prefer Capture to Nebulosity for image acquisition - I run it in Parallels or out on the Netbook. It just works so smoothly with my 314L+ that I like using it (as long as I remember to click the little check box that saves the subs rather than just keep rolling through the capture without saving, made that mistake a few times). I do use Nebulosity every once in a while when I want to use the auto-dither hooked into PHD, but otherwise do prefer to use Atik's software)

[ollypenrice]

I thought the warm up was really for the 2 stage Peltier cameras. Is it really needed on the 314L? I don't know, but surely there is no need to run that chip ultra cold? It does bring its own issues if it's very damp, which it rarely is here.

Olly

[shaunster]

The images that the 314 produce are quite small however, I find now having used both I much prefer the 383 with its much larger chip and pixel count. This allows you do resize the images smaller and produce a much sharper result. I also like to have my images displayed on my desktop and the images the 314 produce simply were not big enough to cover a HD monitor without having spaces around the image. Just my thinking..

[Deneb]

another vote towards the Atik Path. Whatever camera you choose in the Atik range, one thing has to be said the operating software is simple to use even for a beginner.

Nadeem.

[blackparticle]

Heh.. I hate being faced with too much choice !

I think with the Atik's then, I'll try and get Martin from FLO to bring up a couple to the NLO next time I'm in Devon so I can try them out before making a decision.

In the meantime though, I noticed that there was an SXV-M8C for sale on here at a bargain price so I'm going to go for that. I've contacted the seller and have secured the option on it.

OSC - Sony ICX406AQ SuperHAD CCD - 2312 x 1720 pixels - 3.125uM pixel size - 16bit - TEC down to minus 30deg C - Anti-blooming - Decent specs concerning sensitivity and read-out noise etc - ST-4 guideport and serial control interface - recent firmware upgrade and service by Terry Platt and only 200g (which could be helpful as I was getting some focuser droop with the 66 and a DSLR)

I did consider listing it in the original line-up but at the RRP of around £1100, it was up against stiff competition. At the asking price it made it too hard to resist when compared with an astro-modded DSLR.

If it turns out to be unworkable at telescope focal lengths then I can always get a t-ring adapter for it and use it with short focal length lenses instead as a wide-field imager and my camera can become a camera again.

I calculate the pixel size is roughly half that of the Pentax K10D so in theory, exposure times are going to be halved before the mounts errors creep in. With the NEQ6, I can get at least 2 mins unguided (without PEC training) at 400mm focal length without having to drop any frames and these past months have taught me a lot about working with only 20 second subs... Heck.. I was even getting 45 secs the other night at 1800mm with the Mak 150 before the clouds ruined my experiment.

I think it's a good first step anyway and leaves me plenty in the budget for a guide-cam and a few other accessories.. like a decent field flattener/reducer.

[antimorris]

If it helps your decision at all, If i had the money, I would upgrade my 314L+ to a 4000. A larger chip would be nice

[blackparticle]

There was finally a decent break in the clouds last night so I got to try out my SXVF-M8C.

I did a quick M27 as the scope cooled but it was slightly out of focus. I can now see how the focus-lock on a scope is very important. It took me a while to work out how to get it locked while having a chance of retaining focus. Having a live preview on screen certainly helps. The M8C feels much less forgiving of focus than my DSLR.

On the Equinox 66, even at 400mm, everything seems really big due to the tiny pixels in the camera. I lost about 1/3rd of M31 from each edge in the frame so I tried M33 instead. A rough calculation and I estimated 60 seconds for unguided subs would mean good consistency from the NEQ6 so this is a quick stack of all from the session. When I get more time on it I think I can be more picky.

87 x 60s - Equinox 66 / M8C - (20 x Darks applied / No flats) - Full frame resized to 800 x 608 - 36% image size

I'm quite impressed with the results for such a quick test. Over-processed due to lack of total data but setup was painless, Nebulosity ran the capture sequences perfectly and very little imaging time was wasted due to malfunction or bafflement. Even when the cloud front rolled over and threatened a soaking everything was packed away and safe in under 10 minutes.

A big thumbs up for my new toy.

[Komet]

And I'd go for the 314L. QHYs get far more discussion on how to sort out this or that issue than Atiks, which rarely get any at all. I have five in very heavy use and find them reliable.

Olly

I have to interject here ..... I have a QHY IMG2Pro which, like the H9 and 314L uses the 285 chip. It is a gorgeous camera. I find it very reliable. It has amazing cooling (down to -45) which gives really quiet images. Having handled a number of 314L subs I can only say that they have had more hot pixels than subs produced by mine. All three cameras can produce the same quality of images - QHY cameras should not be dismissed. (Having dealt with their customer service also all I can say is that it was fun and very, very helpful despite them being on the other side of the globe). It connects via ASCOM and is very stable.

Would I recommend it? Bloomin' right I would

[blackparticle]

The same image processed with Photoshop. I can certainly see the potential of this camera now. Just got to give it a decent full nights imaging.