Benjamin B
Pooh-Bah
Reged: 06/21/04
Posts: 1156
Loc: Sweden
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I am now close to buy a CCD. But I still have much to learn. What CCD is the best? What should I think of when buying a CCD? I have my LX200 10". What magnification will it be with thees CCD`s? I will also buy a Refractor, like the Takahashi. I want to buy a good CCD. Some advice pleace.
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G11/Gemini
APM TMB 80/480 super apo
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EricCCD
Carpal Tunnel
Reged: 04/14/04
Posts: 1945
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Benjamin,
Here's my take (please note that I am an SBIB bigot  ):
SBIG Camera:
Pros:
Guiding capability is built in.
Built-in guide chip helps reduce flexure issues when guiding with a guide scope. This also addresses mirror flop issues to a point.
Built-in guide chip also allows for use of SBIG's AO-7 adaptive optics device, which helps turn the LX200 from an OK imaging mount to a terrific imaging mount. With the AO-7, you can image at f/10 for high-res imaging.
Built-in guide chip simplifies setup somewhat: there will be less equipment to setup (no extra guide scope, etc.)
Cons:
Finding a guide star to show up on the guide chip can sometimes be aggravating.
When using filters, finding a suitable guide star can become REALLY aggravating.
When using narrowband filters, you may end up needing a separate guider.
You will need to learn about taking dark and flat field frames. This is a must for SBIG cameras.
Starlight Express:
Pros:
Lighter than SBIG.
Less need for darks, and even flats (though I don't understand how SX users have less need for flats).
Separate guider eliminates the Ha/narrowband imaging problem.
Cons:
Guider is a separate purchase.
Separate guider brings up mirror flop and flexure issues.
There may be more, I may add them as I think of them.
Overall, I don't think you can go wrong with either camera. I've seen outstanding images taken with both. It's just a question of how you want to tackle the guider technology of one versus the other.
HTH,
Eric
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Suk Lee
Post Laureate
Reged: 10/07/03
Posts: 4534
Loc: Pleasanton, CA
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Quote:
(though I don't understand how SX users have less need for flats
They don't.
If your optical train vignettes or has dust in it, you've got to flat process.
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melvy
professor emeritus
Reged: 10/17/03
Posts: 710
Loc: Shoreline WA
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To help reduce frustration I will add some things I have found out the hard way. You are not going to be guiding with a LX200 at over a 2m FL. Even at F6.3 you will need the AO7 to get much past 3 minutes. My guess is your image scale will be at around .58 or so and that just takes more precision than the LX200 has.
Now with the AO7 its a whole new ball game and with good alignment I can get 3 hours or more. I still do not use the LX200 to make any guide adjustments it just seems to mess things up.
Good luck!
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WO Megrez 80 SAPO
WO 66 SD APO
TMB SS 130 APO
C8 XLT SCT
Losmandy GM-8 w/Gemini
Losmandy G-11 w/Gemini
Discmount DM6
SBIG ST-2000XM/AO7
Marc Elvy
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Benjamin B
Pooh-Bah
Reged: 06/21/04
Posts: 1156
Loc: Sweden
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Suk Lee
You have the ST-2000XM. I have seen that you have taken great pictures with this CCD. Is it difficult to take pictures with it? You have the XM, Black and white? Is it better to buy the Black and white and buy a filter wheel? Is the Color ST-2000 not that good?
How critical is it to be in a place where is very dark to take good ccd pictures?
I have 2500mm Focal on my scope, I do have Focal reducer, but how many magnifications will it be with the CCD?
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G11/Gemini
APM TMB 80/480 super apo
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Suk Lee
Post Laureate
Reged: 10/07/03
Posts: 4534
Loc: Pleasanton, CA
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Quote:
Is it difficult to take pictures with it?
Well, no more, particularly, than any other CCD camera. CCD imaging is challenging in general though, with a long learning curve. I've been doing this for 5 years and learn new stuff regularly.
Quote:
You have the XM, Black and white? Is it better to buy the Black and white and buy a filter wheel?
That's my preference since one-shot color cameras are less flexible in filtering options, and are always less sensitive than the equivalant B&W. One-shot's are definitely more convenient though.
Quote:
How critical is it to be in a place where is very dark to take good ccd pictures?
Not very. I do all my imaging from my backyard, several miles from a small municipal airport. The skyglow makes for more processing work, but one of the strengths of CCD imaging is the ability to process out skyglow.
Quote:
I have 2500mm Focal on my scope, I do have Focal reducer, but how many magnifications will it be with the CCD?
The ST2k has a 14.78mm diagonal chip size, so @ 2500mm focal length, the effective magnification is 169x.
Suk
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Benjamin B
Pooh-Bah
Reged: 06/21/04
Posts: 1156
Loc: Sweden
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Suk Lee Thank you so much. One question more. I have a focal reducer 6,3. What focal do I get? from 2500mm to what? The cause I ask it`s because I want to know if I can get the entire sun or the moon in one picture, i have some trubble with that now.
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G11/Gemini
APM TMB 80/480 super apo
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DJMcCrady
Carpal Tunnel
Reged: 06/27/03
Posts: 1692
Loc: Seattle, WA
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Ron Wodaski's CCD calculator is very useful for these kinds of questions. See http://www.newastro.com/newastro/book_new/camera_app.asp.
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++don;
http://starryvistas.net
Tak Sky 90, Tak EM200, STL-4020M
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Benjamin B
Pooh-Bah
Reged: 06/21/04
Posts: 1156
Loc: Sweden
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St-2000XM, is it a good CCD or is there any better that I should think of,. The SBIG ST8E, is that a better camera? What are the difference between CCD and other CCD, can any one explain that please. What should I look for in a camera to know if it`s a good one?
Edited by Benjamin B (08/12/04 03:54 PM)
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Suk Lee
Post Laureate
Reged: 10/07/03
Posts: 4534
Loc: Pleasanton, CA
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The difference between the ST2k and the ST8e the number and size of the pixels and the sensitivities of the cameras. The physicals of the cameras (including the self-guide chip) are the same
The ST2k has 1600x1200 pixels at 7.4 microns pixel size.
The ST8 has 1530x1020 pixels at 9 microns pixel size.
I chose the ST2k instead of the ST8 because of the slightly higher pixel count and slightly smaller pixels (I wanted smaller pixels for both high resolution as well as the ability to do wide-field imaging with lenses).
They're both terrific cameras.
Suk
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Benjamin B
Pooh-Bah
Reged: 06/21/04
Posts: 1156
Loc: Sweden
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DJMcCrady, Thank you so much, that was big help
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G11/Gemini
APM TMB 80/480 super apo
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Undermidnight
BEOTS "Tweener Cup" winner
Reged: 05/25/04
Posts: 3411
Loc: Hilliard, Ohio
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I can only comment on a Starlight Xpress cam. I owned an HX516 which was an excellent camera. High quality, low noise, etc. If you have a Fastar compatible scope, you can use it in that configuration whereas you cannot with the SBIG.
Good luck!!
Jason
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"There's only two things that excite a man, expensive toys and real expensive toys." - Red Green
WO Zenithstar 66 on Microstar Mount
8" Ultima 2000, "Wilma"
8" F/4.2 Ultralight, "Marilyn II"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Figuring
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
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Suk Lee
Post Laureate
Reged: 10/07/03
Posts: 4534
Loc: Pleasanton, CA
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By the way, my first "real" CCD camera was an HX516 and I loved it. Easy to use, very little dark current to deal with (dark current processing on non-HAD CCDs is a real pain). Gave me lots of enjoyment before I started hankering for a bigger chip.
IMHO, the real difference between the Starlight Express and SBIG cameras is the "system" you're buying into. I went from Starlight Express to SBIG because I knew I'd eventually want the AO7 adaptic optics device, which makes self-guiding a BUNCH easier.
Suk
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Benjamin B
Pooh-Bah
Reged: 06/21/04
Posts: 1156
Loc: Sweden
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Hmm...I think I have to Buy one more Telescope if I want to to take pictures like the M31. That is a really big Galaxy. perhaps Takahashi would be nice?
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G11/Gemini
APM TMB 80/480 super apo
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Suk Lee
Post Laureate
Reged: 10/07/03
Posts: 4534
Loc: Pleasanton, CA
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 Heh heh, another victim of FOV/Focal length matching...
An FS60 would be nice...
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Benjamin B
Pooh-Bah
Reged: 06/21/04
Posts: 1156
Loc: Sweden
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Do I have to buy the book to sign up on this page? http://www.newastro.com I would like to have the full version becouse I dont have the ST-2000 in the program, just other SBIG`s
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G11/Gemini
APM TMB 80/480 super apo
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DJMcCrady
Carpal Tunnel
Reged: 06/27/03
Posts: 1692
Loc: Seattle, WA
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You don't have to buy the book, although if you do you can get the full version (which just has more sample images and evidently a larger database). You can add your own CCD cameras as well if you know the specs. In fact, Suk's e-mail above has the exact specs for the ST-2000.
BTW... it's an excellent book, and you absolutly should buy it.
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++don;
http://starryvistas.net
Tak Sky 90, Tak EM200, STL-4020M
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TeamGS
Post Laureate
.gif)
Reged: 01/20/04
Posts: 3073
Loc: Elk Grove, CA
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Quote:
To help reduce frustration I will add some things I have found out the hard way. You are not going to be guiding with a LX200 at over a 2m FL. Even at F6.3 you will need the AO7 to get much past 3 minutes. My guess is your image scale will be at around .58 or so and that just takes more precision than the LX200 has.
Hey Marc,
Apologies if I have totally misunderstood your post, but are you saying that, even with an f/6.3 reducer, that the LX200 can't be accurately guided for more than 3 minutes without an AO7?
Regards,
Gary
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Celestron 80ED
Losmandy G11
NexStar 80
Starlight Xpress SXV-H9
SXV guidehead, ToUcam 840
http://www.teamgs.org/astrophotography.htm
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Suk Lee
Post Laureate
Reged: 10/07/03
Posts: 4534
Loc: Pleasanton, CA
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Gear slop. Effectively, the AO7 takes the mount out of the equation.
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TeamGS
Post Laureate
Reged: 01/20/04
Posts: 3073
Loc: Elk Grove, CA
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Hey Suk,
I am still confused (as often seems the case  ).
I routinely guide my LX200 for 5 minute exposures using the f/6.3 and my MX7-C with STAR2K. I have gone as long as 10 minutes, and would like to try longer, when I get the time. It seems to me that I have seen many great images with LX200's that were longer than 3 minutes, as well.
While I understand the benefit of the A07 for SBIG users, I guess my question is regarding the tracking ability (or lack thereof)of the LX200.
Regards,
Gary
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Celestron 80ED
Losmandy G11
NexStar 80
Starlight Xpress SXV-H9
SXV guidehead, ToUcam 840
http://www.teamgs.org/astrophotography.htm
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