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Atik 460Ex or 383L?


gnomus

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I have been taking pictures with a modded Canon DSLR for a little while.  In the next couple of months I intend to get hold of a mono CCD camera.  I photograph mostly through a Skywatcher ED80.  I also have a C8 Edge.  I have tried taking pictures through the C8, but have had mixed results (and by 'mixed', I mean 'poor' and awful').  I will have another go with the C8, once I develop some consistency with the ED80.

I did a bit of research and had pretty much settled on an Atik 460Ex.  I was pretty close to buying this camera.  However, in the last few days I keep seeing threads on this forum about how supercalifragilisticexpialidocious is the Kodak KAF 8300 CCD sensor.  I am now beginning to doubt my choice and wonder if I should be going for the Atik 383, which features this chip (and is a fair few quid cheaper), or some other camera altogether.

What are the relative merits/demerits of either camera?  (I did try doing a search on here for a 460 vs 380 thread but couldn't find one.)

If anyone can help machete me out of this tangled jungle of indecision in which I now find myself, I would be most grateful. 

Thanks in anticipation.

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What is your priority? What sort of imaging do you do? This will have a great bearing on the decision. If you like to do widefield nebula images the sort at which Sara excels at in narrowband and Olly in broadband then the chip real estate of the atik 383l will be vital - no need to mosaic to get your targets in to frame, that will save you hours.

If you're a little more like me and like to get up close and pick out sections of interest in larger nebula or galaxy imaging (apart from M31) then the small(er) and sensitive quiet chip of the Atik 460ex wins.

It's down to your taste really - what do you want to image?

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I love my 460 at 480mm focal length. But the difference is basically sensor size and pixel size. Use a FOV generator for your current and potential future imaging scopes with each ccd to see if you like the FOV it will give.

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An interesting quandry and one that many, including myself have agonised over. For what it's worth here's my take on it.

I was using an Atik 460 and prior to that a 314L+, so when I came to upgrade my camera as the Atik wasn't really cutting it with regards to cooling out here, I was rather partial to the Sony chip by now.  I eventually went for a QSI690 (the same chip as the 490) and if I'm honest I very soon became to regret it.

Don't get me wrong the chip is great, but the size is small and that's all there is to it. I found that in order to get the NAN and Pelican in I had to do a 2x2 mosaic, the same with the entire Elephants trunk. I have to say that mosaics, while rewarding have become rather tedious and wearing. Now I wish I'd gone with the 8300 Kodak chip. I would have gained in real estate, which is important to me. 

I am running two systems with the one camera - I accept that I have to make compromises as I have a focal length of 330mm at the short end and 1.7m at the long end. 

I guess as John says you need to be sure about what you specifically want to image - I want wide field with the 330mm and zooming in to catch lovely close up's at 1.7m. For me, I firmly believe that the Kodak 8300 chip is better suited to me.

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The 8300 chip does produce a good number of hot pixels, which all disappear as by magic when you stack your subs. I fail to see the problem with hot pixels for that reason. I have yet to find one left after the stackig is done.

As have been stated in other threads on this subject, the real estate and reasonable pixel size makes the 8300 the best all-rounder.

/per

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You can certainly use 1.25" filters with the QSI and Moravian as the integrated filter wheel keeps the filters close to the sensor. 

I remember reading differing reports of the smaller filters with the 383 - Some said yes and some said no.

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You can certainly use 1.25" filters with the QSI and Moravian as the integrated filter wheel keeps the filters close to the sensor. 

I remember reading differing reports of the smaller filters with the 383 - Some said yes and some said no.

When I first looked into this, I was tempted by the all-in-one (camera + filter wheel + OAG) packages.  However, I do attempt some lunar and planetary work with my ZWO ASI120.  The idea of having one filter wheel that I could use with the ZWO and the CCD camera seemed very sensible - 'one wheel to rule them all ... and in the darkness bind them', as it were.  

Accordingly, I have an EFW 2 on order from FLO.  I already have a set of 1.25" Baader LRGB CCD filters.  Therefore, I ordered the 9 x 1.25" carousel for the EFW wheel.   I could, of course, change direction (yet again).  Another issue, however, is that the 2" carousel only holds 5 filters.  Although I intend to begin with only L,R,G & B, I have no doubt that I will want to get a set of NB filters down the line. Seven (or eight) into 5 won't go.  I know I could strip the wheel down every time I wanted to change from LRBG to NB, but ........ (I'm a bit lazy, don't you know). 

The QSI seems to be about £1000 more expensive than the 460EX,  and (as far as I can tell) there appears to be only one UK supplier.  The Moravian is a comparable price (with integrated wheel), but the blurb here  - http://www.tringastro.co.uk/moravian-instruments-g2-8300-monochrome-ccd-camera-7935-p.asp - suggests that 1.25" filters are not suitable.  For convenience, I quote the relevant section on that page:

The CCD imaging area is somewhat larger that the clear aperture of standard filters in 1.25 inch filter cells. Such filter cells cause vignetting in the image corners. This is why the filter wheel with 6 positions is not offered with G2-8300 and filters for 5 positions filter wheel are not standard 1.25, but larger filters with 31 mm diameter.   31 mm filters do not cause vignetting on vast majority of optical systems, but they are significantly cheaper and more compact compared to 2 inch filters or filters in M48 threaded cells.

This seems to suggest that 1.25" filters are never a good idea for the larger chip.    

This discussion is very helpful to me in getting my mind straight as to the best option.  Please keep the thoughts coming.

And thanks again to those who have taken the trouble to respond so far.

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Sorry if I've misled you about the Moravian and being able to use 1.25" filters..... That was what I'd heard from folks who knew people using the Moravian system.

Qsi can definity use 1.25" filters..... There are quite a few folks using them.

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Sorry if I've misled you about the Moravian and being able to use 1.25" filters..... That was what I'd heard from folks who knew people using the Moravian system.

Qsi can definity use 1.25" filters..... There are quite a few folks using them.

Don't apologise, Sarah.  I am extremely grateful for your expertise in this matter.  It is helping me a lot with my research.  I have had another look at the wheels and I see that I can get a 7 carousel wheel for the EFW 2 that will take 36 mm unmounted filters.  I have no idea how 'unmounted' works as yet, but I think the 36 mm filters would allow me to use the 383L (and of course could be used with the ZWO.  That would mean that I could have L, R, G, B, Ha, OIII, and SII all set up in the wheel.  

Given that the 383L offers a larger field of view, I wonder why the 383L is roughly £250 cheaper than the 460EX.

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Having played around with FLOs FOV calculator, I am increasingly tempted by that 383L.  I have seen one or two reports on the Internet about 'blooming' when binning at 2x2 (something I believe that I will be doing with the RGB shots).  Is this a big issue?

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The 8300 chip does produce a good number of hot pixels, which all disappear as by magic when you stack your subs.

They didn't when I stacked my images and I used to have to spend hours having to manually clone them out.  Even with dithering.  One of the reasons I no longer have it.

Carole 

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The Moravian is a comparable price (with integrated wheel), but the blurb here  - http://www.tringastr...mera-7935-p.asp - suggests that 1.25" filters are not suitable.  For convenience, I quote the relevant section on that page:

That's one of the downsides of an honest camera producer :)

I have a Moravian G2 8300. The cooling is the same as the QSI and therefor cooler than the Atik, SX and QHY ( Nice to have on a Full Frame Kodak chip ) but warmer than an FLI. It has a built in OR bolt on filter wheel. I use the built in. The filters I use in general are the 31 mm unmounted, also the same as the QSI. I can use 1.25" and 31 mm filters on my wheel and have done both. I have used down to f2 with the 31 mm and had no significant vignetting. I have used 1.25" through my refractor and had no significant vignetting. I have also worked with QSI files through a 1.25" down to f4 and seen no vignetting that doesn't disappear with flats. So there you are - The horses mouth as they say. I would ALWAYS recommend flats no matter what.

Now to the 8300 chip itself. It is a bit noisy. I must admit to being a little disappointed when I first compared the chip to a Sony interline. My opinion has changed since then and I know the 8300 and the 814 chip have the same dynamic range at 71db ( Look up the lecture by Kevin Nelson of QSI ). After proper calibration I doubt you'd see much difference. I no longer use Darks ( !! ). I use a combination of a Bad Pixel Map type calibration in tandem with a Sigma clip. I don't get any remaining hot pixels. Enough subs and a BDM gets less necessary and works very well even with just dithering and a Sigma clip.

One good thing about doing experiments and keeping results is that you can see what goes on. I've included two tight crops of a single 8300 sub that's been treated with a BPM. How many hot pixels can you see remaining ? Not many. Only a slight stretch has been applied so you can see the results - nothing else.

Dave.

post-493-0-46897000-1434796647_thumb.jpg

post-493-0-70746900-1434796657_thumb.jpg

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The clean nature of the 460, able to use 1.25" filters, and compatibility with the less expensive Starlight Xpress 7 position Filter wheel were the deciding factors in my 383L vs 460exm decision. I said it before Atik made this a difficult decision by pricing these cameras where they did.

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I use the 383L+ with 36mm unmounted filters in the EFW2 - works well, the very small degree of vignetting is easily corrected with flats.  The filter wheel comes with tiny caphead screws, rubber 'o' rings and small plastic washers that secure the filters within the wheel.  They fit securely and orthogonally.  The only 'restriction' ( :smiley: !!, hardly really) I found was that Astrodon only supply 5nm NB filters in their 36mm unmounted range.

The combination of EFW2 and Atik ccd (whichever you choose) does work well.  However, if I have to pick a weak point, it is the two grub screws that attach the ccd to the EFW2.  I do find that I have to fettle and fiddle to get the best orthogonality with my short FL FSQ85 and reducer at F3.9, I think I can get the minutest of tilt in the system if I'm not careful, which can show with slight elongation in one of the corners (depending on rotational angle for framing).  I am being picky here though.  Nevertheless, I am contemplating buying the QSI683 becuase of its better build quality.  I would say that the 383L+ is a great camera for the price point and provides ample quality for the overwhelming majority of time I'm imaging.

HTH

Barry

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They didn't when I stacked my images and I used to have to spend hours having to manually clone them out.  Even with dithering.  One of the reasons I no longer have it.

Carole 

Something wrong there, then Carole. Even with the very noisy KAF1100 chip I don't get residual hot pixels. And that's without dither because we can't dither the dual rig.

On FIlter size, Baader do a mid size targeting the 8300 chip.

The Kodak will calibrate out once you have the routines sorted. The Sony is a nice chip to use but small. Thatreally is about it so far as I can see. Since we run three full frame CCDs here you can guess where my heart lies on chip size!!

Olly

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Well I don't get that problem with my 314 and 460 Sony chips, so maybe it was that particular camera.  It drove me mad.

Carole 

The Sony chips really don't need darks at all most of the time so if something wasn't working in your calibration routine it wouldn't show up on the Sony results anyway. It's easy for something to be not quite right in the calibration flow and, when it isn't, it's true that the Kodaks don't clean up properly. Problems I've had with calibration have arisen from;

Darks being upside down after a software flip in the capture programme.

Darks being made with slight light leakage.

Darks being past their sell-by date.

I guess it's also possible for a problematic camera to produce variable noise, too, due to some internal issue but perfectly clean Kodak chip resultsare possible.

Olly

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I have a QSI 583wsg-5 and a 683 wsg-8. love them both ! I use 1.25" filters at present but plan getting a set of 31mm. Only reason is changing over to Astrodon for the 683. So far not seen any vignetting but don't expect to with working at f7. So far cannot fault their build quality.

I would have loved a bigger chip, but finances (other half, well that's my excuse anyway) prevent that.

There is a good size chart on FLI website for comparison.

http://www.flicamera.com/pdf/ccdposter.pdf and http://www.flicamera.com/pdf/FreedomOfChoiceCCDmatrix.pdf

Derek

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I may be able to change my EFW 2 order to a 7 x 36 carousel. I may also be able to exchange my unopened set of Baader LRGB filters. So switching to the 383L would be achievable. I am intrigued by the Moravian camera, but hadn't really heard of it before this thread. My reservation about the Moravian would be the probable lack of 'assistance' I might find here because they seem not to be as popular as the Atiks or QSIs. The Moravian is a very good price, however. The QSIs are no doubt good quality, but are more than I am prepared to spend right now.

I am leaning towards the 383L. I hadn't appreciated that the FOV was only a little less than I have been getting with my Canon.

Barry: Do I take it from what you say that it is better to leave the EFW 2 attached to the camera, once you have it set right? That would put paid to my plan to use the EFW 2 for planetary work.

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They didn't when I stacked my images and I used to have to spend hours having to manually clone them out.  Even with dithering.  One of the reasons I no longer have it.

Carole 

You need to use a standard deviation based stacking rejection algorithm, like Pixinsight's. Many of the simpler stacking softwares don't do fancy stuff like sigma rejection. Pixinsight's stacking removes all airplane trails, all hot pixels and much of the color noise if used with dithered subs.

/per

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As general information, I never use darks with my QSI 683 wsg8, only BIAS frames to get the base level right. It has the 31mm Astrodon filters and there is no vignetting with the FSQ-106 and the TEC-140. Real estate rules ;)

/per

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I may be able to change my EFW 2 order to a 7 x 36 carousel. I may also be able to exchange my unopened set of Baader LRGB filters. So switching to the 383L would be achievable. I am intrigued by the Moravian camera, but hadn't really heard of it before this thread. My reservation about the Moravian would be the probable lack of 'assistance' I might find here because they seem not to be as popular as the Atiks or QSIs. The Moravian is a very good price, however. The QSIs are no doubt good quality, but are more than I am prepared to spend right now.

I am leaning towards the 383L. I hadn't appreciated that the FOV was only a little less than I have been getting with my Canon.

Barry: Do I take it from what you say that it is better to leave the EFW 2 attached to the camera, once you have it set right? That would put paid to my plan to use the EFW 2 for planetary work.

I switch between my 460EX and 383L+ depending on which scope and image scale I want for the target, eg my WO FLT132 with 460EX for galaxies at 1.24"/px (or 1.0"/px with flattener at F7).  So there is some fiddling when I replace the 383L+ on the EFW2.  The fiddling really is minor and is only needed when I use the 383L+ at the faster F ratio.  If you don't need to make any changes, I would leave it alone when you have the image train set to your liking.

Barry

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As general information, I never use darks with my QSI 683 wsg8, only BIAS frames to get the base level right.

Likewise - I dither my exposures and use 'SD Mask' in MaxIm DL for my stacking algorithm and this removes any hot pixels or satellite trails easily leaving me with noise-free images with a set-point of -20° C. I do always use Flats though.

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