Atik 11000 under way.

[ollypenrice]

If you read my earlier posts on this camera you'll know that the first ones I received had a problem with banding due, I think, to something called Linear Read Timing. For all I know about CCD electronics you could have called it Yellow Monkey Fever. Atik were faultless in being responsive and did their level best to get it sorted quickly, which they did. In fairness to them the problem was very odd in not showing up in flats or darks but only in genuine images. It had not affected earlier incarnations of the big chip which has, I think, found a new manufacturer. Whatever, the service was great and the camera is running as sweetly as all the other Atiks I've used. (I've either had, or still have, seven.)

The whole point of the 11000 is the size of the chip. It covers just short of 16 times as much sky as the 314L at a given focal length. Pixels are 9 micron, meaning that it is over sampled in a Takahashi FSQ106 at 3.5 arcseconds per pixel. Purists might dismiss the whole idea but the fact remains that the FSQ106/11 meg chip is the biggest single APOD grabbing combination of them all. Here's one from Tom O'Donoghue. http://apod.nasa.gov...d/ap120828.html There are many more. Sky coverage in this combination is 3.9 x 2.6 degrees. In the FSQ the Eagle Nebula and the Swan can easily be imaged together with plenty of space around them. The Horse, Flame, Running Man and M42 fit easily on a 2 panel mosaic.

This brings two advantages. Widefields can be captured fast and, frequently, two objects can be had for the price of one, something which I think our visitors will appreciate.

However, the big chip has some disadvatages, too.

- It needs a flatfield instrument to cover the chip. The Baby Q, alas, couldn't quite do it, hence my move to the 106.

- It needs 2 inch filters, which are expensive.

- It has an M54 thread for attachment to avoid vignetting so some wheels may not offer that (I'm not sure.) The Atik EFW2 has this as an option as standard.

- It has large 9 micron pixels which won't match the optical resolution available in many scopes but, on the other hand, each pixel gets a lot of light.

- The chip is noisy. Darks and bias will scare the life out of anybody used to Sony chips! Does this matter? Not if you calibrate effectively.

Calibration; I started by using temperature and exposure matched set point library darks and acheived mixed results, sometimes fair, sometimes bad. On switchng to a Defect Map and master bias there was a sudden change and the images stacked up as clean as a whistle. Lovely. I stack in AstroArt 5 which supports defect maps. The instructions say to make a master dark and then clip the black point by 2000 ADU. This takes seconds and leaves a smattering of hot pixels on a back background. There's a box in which to put the defect map as you load up your stacking files and you just put a master bias in the box normally used for darks. In my last two images I don't recall cleaning up a single pixel. No columns, no hot pixels (though I do run the hot pixel filter in AA) and no dead pixels showing. This entire process is painless.

I was slow to get going with the 11000 because its targets are really in the Milky Way. In the galaxy season Yves' full frame camera sees most of the action in the 14 inch Dall Kirkham. However, the targets eventually rose over the north eastern horizon and I was able to exploit the new beast. The scale is simply thrilling. It took just 6.5 hours to get this lot;

http://ollypenrice.s...j5GGtP&lb=1&s=O

This is only about 2/3 of full size. Each of the four panels had about 100 minutes or a little less. I feel that this is a fast result in a 7 Nm Ha filter and pretty clean for the time, bearing in mind that shooting also began at very low elevations.

I like it!

Olly

[fwm891]

Very impressive Olly. Superb image detail (as usual). Thanks for the breakdown on your calibration, I've been having problems getting flats to 'work' and tried all sorts of exposure length combos, but not looked at the defect mapping in AA5 - thanks

[michael.h.f.wilkinson]

Very impressive indeed.

[MartinB]

I've been trying not to think about the joys of a large format chip but you keep luring me!

How are you finding the cooling? I don't know what your night time temps are like now but do you think it is good for 38deg below ambient? How long does it take and is the temp maintained steadily? How good is the light sealing e.g do you have to worry about the odd LED in the observatory, can you take darks when it isn't pitch black? How quickly will it download an unbinned star image for focusing and how long for a full sub?. What steps have been taken to avoid condensation?

Sorry about all the questions, the Atik has some stiff competition in this sector but it does score well on price.

[ollypenrice]

Martin,

- Cooling seems good and, yes, it seems to pull about 38 below ambient. My Atik 4000s roundly outcooled Yves' SXVH36 but the big chip may be more of a challenge. It isn't very warm here at the moment so my regular -20C has been easy. Tom uses his 11000 in the intense heat of southern Spain.

- Condensation won't be an issue, I don't think. Atiks have a chip window heater. It would be nice if it were controlled from Artemis Capture but it isn't, it's activated by going into the programe files but if I can do it... It's easy and I guess anyone not running on batteries might have it running gently most of the year. On the other hand the SXV H36 has been stopped for the night on two occasions by chip window fog.

- It's light proof for flats. I took some successful T shirt flats in bright daylight (with a lot of T shirts!) I was getting a gradient on my panel flats, as I sometimes do on all setups for reasons unknown, but these daylight flats were beauties and worked a treat.

- I don't know about darks. I've read a persuasive article suggesting that the full metal cover is a good idea to keep gamma ray hits off the chip so I use the supplied cap for dark taking. From memory this was indoors with normal lighting. Since it doesn't respond too well to darks I can't say whether it was leaking or not but I'd have thought not.

FWHM single star downloads are effectively just in real time. There's no significant wait. Full chip downloads are slow. I haven't timed them but will do so next clear night. Using Bin 4 is good for framing, though. Or Bin 3. That's perfectly bearable and gives a clear enough image in reasonable time.

It's a shame, maybe, that Atik don't make an equivalent of the H36 with the larger version of the 4000 chip. Slightly smaller pixels would be good at shorter focal lengths. I didn't want to desert Atik, though.

Olly

[MartinB]

Thanks a lot Olly, that's really useful to know. A long download isn't such an issue with 30min narrow band subs which is the majority of my imaging but a bit of a pain for shorter LRGB subs. Not the end of the world though, just take longer subs! There's a very tempting QSI coming onto the market soon though

[ollypenrice]

Thanks a lot Olly, that's really useful to know. A long download isn't such an issue with 30min narrow band subs which is the majority of my imaging but a bit of a pain for shorter LRGB subs. Not the end of the world though, just take longer subs! There's a very tempting QSI coming onto the market soon though

Aha. QSI are expensive but so well made and thought out. I've imaged with a couple down here and seen a good few. Very tasty. I suspect that a big chip QSI would break my bank, though!

Olly

[cfpendock]

I found your post very informative, Olly. I was particularly interested in your calibration development, and your use of a Defect Map. I was wondering if you had to follow a similar development with your other Atik cameras, or was this particular to the 11000? I don't want to comment on your images, as usual they set the standard!

Chris

[NickK]

Nothing quite prepares you for the immense size of the thing...

I had a play testing the 11000 with the OSX drivers whilst over at Olly's in Jan.

[E621Keith]

Very impressive bit of kit

Doesn't the FSQ106 have an enormous 88mm image circle. Next stop Apogee Alta 4320

[ollypenrice]

I found your post very informative, Olly. I was particularly interested in your calibration development, and your use of a Defect Map. I was wondering if you had to follow a similar development with your other Atik cameras, or was this particular to the 11000? I don't want to comment on your images, as usual they set the standard!

Chris

I think the big chip is probably more sensitive to calibration. I just used darks with my other Atiks. We found with Yves' SXV H36 that a defect map worked well for calibration of chip noise but played hell with flats calibration. You can't win!! Don't ask me why this should be the case. It just was, so far as I could tell. I don't know why.

I'll take this opportunity to repeat a superb bit of advice from Peter (Psychobilly) with regard to focus. For fine focus, pick a star at the intersection of the one third lines. Focus on a star here and you'll get a better compromise focus across the whole chip. In other terms, you'll get a focus which lasts longer as cooldown wreaks its havoc.

Olly

[ollypenrice]

Very impressive bit of kit

Doesn't the FSQ106 have an enormous 88mm image circle. Next stop Apogee Alta 4320

Can't hear you, can't hear you!!!

Olly

[Tim]

I'll take this opportunity to repeat a superb bit of advice from Peter (Psychobilly) with regard to focus. For fine focus, pick a star at the intersection of the one third lines. Focus on a star here and you'll get a better compromise focus across the whole chip. In other terms, you'll get a focus which lasts longer as cooldown wreaks its havoc.

Olly

Did I just shout to repeat that? Well it was worth it

Very interesting stuff Olly. I was weighing up the options for the 11000 yesterday at the IAS. Will probably go for 50mm unmounted filters I think, can't stretch to a FLI wheel atm.

I am wondering how the camera would fare on the two scopes that I think will make up my 'permanent' setup.

The Esprit 150, focal length 1050mm, f7, not sure on the illuminated field on this. =1.74 as/pix FOV = 77 x 116 arcmins

and the C11EdgeHD, focal length 1950mm, f7, illuminated field at f10 is 42mm, not sure with the reducer. =0.95 as/pix FOV = 42 x 63 arcmins

Any thoughts?

Thanks

Tim

[Tim]

Oh, I also have a Quattro 10" F4, I have no idea what the illuminated /flat field is on that, but that would give 1.85 as/pix with 82 x 123 arcmins FOV.

Although this scope may be on the list of things to sell at some point.

Cheers

[MartinB]

and the C11EdgeHD, focal length 1950mm, f7, illuminated field at f10 is 42mm, not sure with the reducer. =0.95 as/pix FOV = 42 x 63 arcmins

29.4mm ??? 7/10 x 42? I think this is a best estimate assuming the aperture of the reducer doesn't cause any additional restriction.

[ollypenrice]

It looks bang on for the Esprit. I'm aiming to get the flattener for the TEC when I've seen how the money is settling down. The image circle for the 11000 is, I think, 45.6mm. 42mm won't cover it but how bad will the edge distortions be? No way of knowing without trying it. You might get away with it but a bit of cropping won't be the end of the world.

I'm glad you agree with the importance of Peter's tip. It can be a game changer.

Olly

[Tim]

Apparently even with the reducer the C11EdgeHD is 42mm circle. I can hardly think of an image that I haven't had to crop the edges off anyway, so it might be an interesting tool at that focal length.

[ollypenrice]

Apparently even with the reducer the C11EdgeHD is 42mm circle. I can hardly think of an image that I haven't had to crop the edges off anyway, so it might be an interesting tool at that focal length.

On flatfield scopes reducers tend to reduce the image circle, unlike FF/FRs for normal scopes.

Olly

[laser_jock99]

I'm really tempted by this big chip- trouble is it would mean a complete upgrade all round since not many scopes can illuminate it correctly. Need to find about £7K to make it happen. Followed by a mount upgrade.....