CCD strategy

[Thommy]

Dear all,

Some background: So far I have used an old MX7C OSC, but would now like to move on with Mono. There is a catch though. I have recently bought a second hand CGEM and a second hand 8" f/4.5 Newton, but with the idea to use it for a couple of years, only. Just to get the grips with imaging mono with a goto mount. My "final" choice of telescope (yeah yeah, I know ...) would probably be a 12" f/4.5 Newton on a EQ8 or similar. I'm mostly interested in capturing images of small distant galaxies, so definitely not a widefield man!

As I see it there are four strategies: 1) buy a cheap mono camera, like an QHY 6 or Orion Starshoot G3, and get rid of it again when I upgrade. 2) Buy a Lodestar X2. It's very sensitive, it is possible to take longer exposures, though it is intended for guiding. I can use it as an electronic eyepiece to impress friends, and when I finally buy my preferred setup, I have one of the best guiders available. Or 3) I invest in a camera that would fit my future preferred setup. Then I dont waste money on something that is very temporary, anyway. Finally, 4) Buy a second hand Atik 314L+, QHI img2pro or alike. That would be nice, but those are very hard to find for a reasonable price. 

I think, I would disregard bullet 3), but for the rest I'm a little confused  . Anyway, I wellcome all considerations, ideas and so on. 

/Thommy

[pete_l]

How easy it is to spend someone else's money

I'd rule out the Lodestar as an imaging camera as it's not cooled.

The QHY6 sounds like a plan! It has the same QE as a 314L+ (65%) and pretty much the same sized pixels. So as long as your small targets will fit on its small chip, it should to the job. I believe the early problems this camera had with banding have now gone away (anyone know better?)

Then in a couple of years, reappraise what's available and what innovations there have been - and whether your interests have changed,

[ollypenrice]

Your small galaxies need resolution and there are two ways (interconnected) to get it. You can chase resolution by increasing FL or reducing pixel size. It you don't want to spend a bomb on a big scope and mount then someting like an Atik 490 with small pixels will get you resolution with shorter focal lengths/smaller scopes/smaller mounts.

Olly

[Thalestris24]

Hi

Thy qhy6 might be ok for you but it is less than 0.5 Megapixel. The ATIK 490 would be lovely but I suspect you don't want to part with that sort of money!!!

A possible alternative might be the ZWO ASI120MM which is essentially the same as a qhy5l-ii. Both are used as guide cams. However, if you don't mind voiding the warranty and you can do little diy engineering and electronics, the ASI has the possibility of doing a cooling mod. I think some people on the forum have done this - maybe do a search? Someone in China has had a go:

http://www.astronomy.com.cn/bbs/thread-242988-1-1.html (scroll down for images).

Other than that, as you mentioned, a second-hand Atik 314L+ would probably be the best bet.

Louise

[Thalestris24]

Hi Thommy

I see Gina has a 314l+ up for grabs:

http://stargazerslounge.com/classifieds/item/4299-atik-314l-mono-ccd-camera/

[Thommy]

Thanks for your replies,

Pete, yes I suppose the Lodestar is too noisy, though I have seen some decent 30s exposures. The idea formed as the Lodestar is very versatile, but I think you're right - the images would probably be too noisy.

Olly, the 490 was actually on my mind for my future setup, so this would be to follow strategy 3. I think Pete's last line makes sense, though. When I'm ready for my future setup, there might be an even better detector, and perhaps my interests have changed by then ...

Louise, the cooling mod of the ZWO camera sounds interesting, I wouldn't mind doing the job, but right now time is an issue. I know that it's very easy to replace the chip of my old camera with a mono chip, but for the same reason I skipped this option as well. I didn't know that Gina offered a 314. With 24 posts, I don't have access to the classified section - it's, well, classified  .

/Thommy

[Thalestris24]

Hi

She's offering it for £750 as she's upgrading. Sounds quite a good deal to me It says to contact her directly - http://stargazerslounge.com/user/13131-gina/

Hth

Louise

[Thommy]

I think I have finally decided to go for option 1 and buy a new QHY 6. I think I would have preferred option 4, and I did find a few of these cameras for sale in the uk or elsewhere outside of DK, but after adding carriage to DK and perhaps insurance, the price will be too close to the price for a new 314L+. 

Thanks for your help (new arguments are wellcome, of course  )

/Thommy

[wuthton]

I think I have finally decided to go for option 1 and buy a new QHY 6. I think I would have preferred option 4, and I did find a few of these cameras for sale in the uk or elsewhere outside of DK, but after adding carriage to DK and perhaps insurance, the price will be too close to the price for a new 314L+.

Thanks for your help (new arguments are wellcome, of course )

/Thommy

Have you checked a field of view calculator? The chip in the Atik 314l is small but the QHY6 is tiny.

[Thalestris24]

Yeah, I wouldn't get the qhy6, tbh. I think you'd find it frustrating! If you can be patient and wait a bit, qhy are bringing out a high QE, cooled cmos 1.3MP (miniCAM5S).

http://qhyccd.com/ccdbbs/index.php?topic=4744.0

They've been beta testing the software for a while though I don't know when the camera might be released in Europe.

Still, it's only slightly smaller than the Atik314l+ though only 12-bit, but seems good value. I'd quite like one!

Louise

[Thommy]

The miniCAM seems promising as a guidecamera, but I'm not to sure regarding its imaging abilities. I did calculate the FOV with the QHY 6 / 8" f4.5 combination to be 19'x14' and with the miniCAM it is 18'x14' - in other words identical! The problem is that the pixelsize is very small - 3.75 mu compared to QHY 6's 6.5 mu. The resolution for the QHY 6 option would be 1.5 "/p, which is quite small for danish seeing, but ok as I would do high resolution imaging. For the miniCAM option the resolution would be 0.86"/p - good if you live in the Andes. I think I would have to bin it, but then there's not many pixels left. But it would be very sensitive!

/Thommy

[wuthton]

The miniCAM seems promising as a guidecamera, but I'm not to sure regarding its imaging abilities. I did calculate the FOV with the QHY 6 / 8" f4.5 combination to be 19'x14' and with the miniCAM it is 18'x14' - in other words identical! The problem is that the pixelsize is very small - 3.75 mu compared to QHY 6's 6.5 mu. The resolution for the QHY 6 option would be 1.5 "/p, which is quite small for danish seeing, but ok as I would do high resolution imaging. For the miniCAM option the resolution would be 0.86"/p - good if you live in the Andes. I think I would have to bin it, but then there's not many pixels left. But it would be very sensitive!

/Thommy

The QHY6 is generally considered a guidecam not an imaging camera. If I were you I'd be patient and save some more money for an Atik if you want to go ccd.

Can you borrow a DSLR in the meantime?

[Thommy]

Well, I think (or thought) that the QHY 6 is used both as an entry level CCD camera and/or guide camera. The advantage being that I could use the QHY 6 for guiding when I upgrade. But perhaps I'm wrong! Any QHY 6 users out there? Is it fine for imaging or just scrap?

I wanted the camera for the coming season, but I'm in no hurry. My old MX7C is still working fine!

/Thommy  

[pete_l]

Well, I think (or thought) that the QHY 6 is used both as an entry level CCD camera and/or guide camera.

Yes, it is.

It's at least as capable as the early Starlight cameras, such as the MX716. It has a comparable CCD, cooling and similar resolution.

The only thing "against" it is that it's considerably cheaper than most new CCDs which start at 2 or 3 times its price.

[Thalestris24]

The miniCAM seems promising as a guidecamera, but I'm not to sure regarding its imaging abilities. I did calculate the FOV with the QHY 6 / 8" f4.5 combination to be 19'x14' and with the miniCAM it is 18'x14' - in other words identical! The problem is that the pixelsize is very small - 3.75 mu compared to QHY 6's 6.5 mu. The resolution for the QHY 6 option would be 1.5 "/p, which is quite small for danish seeing, but ok as I would do high resolution imaging. For the miniCAM option the resolution would be 0.86"/p - good if you live in the Andes. I think I would have to bin it, but then there's not many pixels left. But it would be very sensitive!

/Thommy

Sorry, Thommy

I forgot about the small pixels! Duh! I use the qhy5l-ii as a guidecam - it's very sensitive with a qe of something like 73%, I think. The 5s will be similar, but cooled. Next time I'll remember not to just compare resolutions!

Louise