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Armando
member
Reged: 12/26/05
Posts: 50
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Hi @all!
I'm going to buy a Meade 216XT for 300 USD.
I'd like to use it as a standalone autoguiding CCD.
What do You think about it?
According to someone (maaaany reviewers) I should avoid this CCD.
However I compared it to SBIG ST-4.
According to the specs, it's better than the SBIG ST-4.
I don't own a notebook and so I simply need an autoguiding CCD.
If the only (or the most important) reason for the negative reviews I read is the "single button" and the tremendous operating scheme, then I think to be able to ignore this weakness.
What do You suggest?
And what about the price? 300 USD is too much?
Clear Skies!
Armando
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c131frdave
Post Laureate
Reged: 01/17/05
Posts: 4376
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He Armando. Fire off a PM to jrcrilly. I think John either uses one, or has used one. I know he can help you out.
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Tak NJP
Various sizes and shapes of formed glass
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Jared
Post Laureate
Reged: 10/11/05
Posts: 4554
Loc: Piedmont, California, U.S.
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Don't underestimate the role played by the "one button operating system." The whole point to an autoguider is to relieve you from the tedious task of guiding manually. If you end up spending forty-five minutes getting the thing kicked off and tracking, you haven't accomplished much.
I have owned one when it first came out--along with the 416 imaging camera--and never had any luck with the guider. Some of it can be put down to my total lack of experience at the time, but by no means all of it. The user interface really makes this unit a challenge, regardless of how good a unit it is on paper.
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- Jared Willson
- TV 60iS refractor
- 80mm SV/LOMO refractor
- A-P 130 EDFS refractor
- Planewave 12.5" CDK
- A-P 900 mount
- A-P Mach1 GTO mount
- Takahashi Teegul SP travel mount
- SBIG STL-11000 C1 camera with AO-L
- Some heavily light polluted skies
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Armando
member
Reged: 12/26/05
Posts: 50
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Hi Jared,
first of all thank You for Your advise.
I just downloaded the corrected flow chart of Meade Pictor standalone autoguiding CCD. I perfectly agree with You about the "not very comfortable" one button operating system. 3 buttons and a better display with 3 different indications of the different commands associated to 3 buttons should have been a good idea...
However there is a little of logic in the flow chart.
I hope to be able to use the Pictor with no trouble.
I think I'll make also a parfocal eyepiece by using one of the chinese eyepieces I own to avoid spending too much time to focus.
I won't use the autoguiding on the same telescope by an off axis guider: I'll use a little Maksutov mounted on a support with micrometric controls in both directions.
So I think I won't have to spend so much time to be able to calibrate and use the CCD as standalone autoguiding.
However if I'll find troubles I'll surely remember Your advices.
Let's hope in a better luck 
Thank You again and Clear Skies!
Armando
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msholden
Pooh-Bah
Reged: 09/21/05
Posts: 1193
Loc: Connecticut
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Hi Armando
I went down a similar path about a year ago.
I bought an St-4 and was going to use it with a small mak for auto guiding.
The biggest mistake was probably trying to use a mak. The field of view was quite narrow, and I had problems getting a suitable star on the guiding chip.
For manual guiding, a longer focal length is a good idea. With auto guiding, you don't really need it. The system is happy to pay careful attention and make corrections as soon as your guide star moves one pixel.
I got a couple of useful images with that system, but it was frustrating enough that I decided to upgrade to an ST-2000xm and a laptop. It's much easier to work with.
But frankly, if I was going to do a stand alone auto guider, instead of an St-4 or a pictor, I'd go with a web cam and a laptop. That way you could see what the guide chip actually sees.
And I'd go with a lens with a focal length in the general range of 2-300mm.
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Life is too short to look through bad glass.
Edited by msholden (04/21/06 11:03 PM)
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Armando
member
Reged: 12/26/05
Posts: 50
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Hi msholden,
my small Maksutov focal length is 1250mm. I agree with You: it's too much.
According to Meade the 216 XT should have a 1/4 pixel resolution. Even if we want to ignore the subpixel resolution, because of the E200 film specs, 10um of linear dimension of the 216XT pixel could suggest a good guiding focal length of about 1/2 photo focal length.
However I own a 210mm f/4, a good 2x teleconverter and some adapters to be able to use any lens with eyepieces too.
I also think that when seeing is not good, a manual guiding is required. In these cases I'll guide manually by using my Maksutov.
I don't like the idea to carry a notebook too.
And I should have to make mods to a web cam to obtain good results.
I'll keep You informed about the results I'll obtain by Meade 216XT.
Your experience and the other useful suggestions I found have already saved me a lot of time! I think to be able to successfully use a 216XT.
I also found a good flow chart for Meade Pictor (the diagram map by Meade is really BAD) and I'm going to like the single button operating mode: there is a logic in the scheme since when You think to have to make a middle (or long) press You exactly have to make a middle (or long) press....
I'll keep You informed about my results.
If I'll obtain good results I think suggesting an economical standalone autoguiding CCD could be a good idea.
Clear Skies!
Armando
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Armando
member
Reged: 12/26/05
Posts: 50
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I finally used my Meade 216XT on a Maksutov MC90.
These are my comments:
1. thanks to a parfocal eyepiece no problem to focus;
2. thanks to my piggyback support no problem to center a star on the CCD field (with no notebook);
3. the camera is simple to use also as standalone autoguiding CCD, so no problems because of the single button.
So, no difficulties except for one problem:
msholden, I also had sometimes difficulties to find a suitable star for guiding.
It's simply because my Mak is f/14...
I could solve the problem simply by setting higher exposure times. But for autoguiding I prefer to have an exposure time of 1-2 seconds.
I'll let You know if I'll solve thanks to a 0.5 focal reducer I just bought.
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Clear Skies! 
Armando
Edited by Armando (09/19/06 04:59 PM)
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Armando
member
Reged: 12/26/05
Posts: 50
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I just remembered I had to tell how 216XT camera works as autoguider...
Simply perfectly and with no focal reducer.
It's only required accurate focusing...
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Clear Skies!
Armando
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