Wish list

Here is my wish list. can you all give me some feedback by putting them in order of importance for me? as I'm not sure what would be the best to buy first. I can't solve the problem quickly by buying them all as my Lotto numbers didn't come up again
1. meade 4,000 series f/3.3 ccd focal reducer.
2. " " " f/6.3 focal reducer.
3. Meade 12 mm modefied astrometric illuminated reticle
4. Meade 25 mm Plossel illuminated ccd framing eyepiece.
5. Meade 9 mm illuminated reticle eyepiece.
6. Meade LX series equatorial wedge
7. meade flip mirror system.
Items 3 - 5 I know I don't need each, but what would be the best of them? bearing in mind my eyes are letting me down and I have problems framing for the DSI. I have the Meade 8" LX90
Look forward to your feedback. Thanks everyone.
Bill H.

Hi Bill,
An interesting choice of parts there.
From my own experiance and usage, this is how I'd rate them in terms of how much usage I would use them.

1, meade flip mirror, I had one permanently on the back of my scope for the last 3 years, until I got an OAG and now occasionally swap them around,
Try get the bigger model, as the smaller model can cause (so I read) vignetting on a 35mm frame.
If you do webcam planetary imaging, this device is a major advantage!!

2, F6.3 focal reducer, you can use this for visual and photographic work., very handy!

3, The 12mm astrometric has a fixed centering point, with it you can work out lunar landscape distances and double star positions, and will work for tracking, requires batteries (although I modified my one so it runs off the telescope )

4, The 9mm has an adjustible crosshair, I've read good and bad about this feature, great for tracking as you can put the center on any point of the field of view, its also powered off the telescope, no batteries. I might get one some day.

5,The Meade LX series equatorial wedge should only be considered if you are definitely going to do long expopsure photography. The wedge makes the system more liable to vibration and if it is not very accurately alligned with the pole (takes a good amount of time), your gotos will not work accurately, or so I found.

6, I would consider the Meade 25 mm Plossel illuminated ccd framing unnecessary if you have either of the above eyepieces, lets be honest, once you've taken one image with a camera, you'll know the field fo view, centering can be achieved by either of the above.


7, The meade 4,000 series f/3.3 ccd focal reducer, this cannot be used visually or with DSLRs like the canon. It is for small CCD photography only. Correct spacing from the back of the telescope is critical for achieving focus and correct focal ratio, so if you get one second hand, make sure you get the extension tubes that come with it. If your camera chip is too big, severe vignetting is what you'll get.

I'm not sure if the LX90 has a port on it to run reticle eyepieces, just make sure of that.

Check out
www.mapug-astronomy.net/AstroDesigns/MAPUG/Eyepieces.htm
for comments on reticle eyepiece types, pros/cons.

I hope this helps, just my 2 cents.

Hi Bill - I'm making one overall assumption - your primary imager is the DSI or the LPI.

1. Equatorial wedge OR field de-rotator (preference would be wedge)
2. Flip mirror & eyepiece
3. 6.3 reducer
4. 3.3 reducer (with Dave L's proviso in mind)

I've left out specifics on the eyepieces because I don't know too much about them - sorry. But the astrometric eyepiece would probably be the one I'd go for...

The wedge will give you non-rotated images once you are polar aligned. Beware, polar aligning to the accuracy required for imaging deep sky is tedious. The field derotator will eliminate that step but its another electronic/motor device that can screw up - the wedge is just mechanical.

Dave L's advice is spot on - just the order is different...

And by the way, if you want to try-before-you-buy, you can have a lash at my Celestron 6.3 reducer. The Meade and Celestron are the pretty much identical in what they do - or so the bloke at Woodland Hills Camera in LA told me.

Hope this helps...

Cheers

Dave McD

Many thanks Dave L and Dave McD.
The LX90 has two auxilliary ports for accessories, so should be OK there Dave L. I would certainly love a go with your 6.3 dave McD, it can make a difference when deciding on purchasing something. I could pick it at the same time as that little mount you you bought the other week :lol: :lol: Don't cry i'm only joking (no I'm not) Just let me know when you are out for the evening :twisted:
Thanks again. I shall see if any other advice comes in and colate everything.
Bill H.
PS. You will notice I haven't put books on the list, I already have tips on what books to buy and my book shelf is groaning under the wieght of those and others!

Bill.
You should ask someone like Michael O'Connell about those aux ports as he also has a lx90, just to be sure. On the scope here, its maked reticle, so there is no ambiguity.
With meade equipment, there is a nasty feature called "built-in self destruct" that activates when you plug the wrong plug into the wrong socket. :lol:
this can also happen if you plug in or out at the wrong time.

If you were nearby, I'd lend you the flip-mirror, its definitely worth trying out equipment before you buy it.
I've bought stuff over they years, and when I look back at some of it I think, what was I on :oops:

If you want further experiances of using a field de-rotator, check out
www.mapug-astronomy.net/AstroDesigns/MAPUG/Derotatr.htm
The mapug site is fantastic for SCT info, alot of it can be applied to celestron scopes also.
I personally wouldn't use one, they do work, but are more difficult then a wedge to use, they can have many quirks.

Bill,
Interesting list there. Here's what I'm thinking:
1. Only useful for CCD work.
2. Useful for both CCD and visual. However, wide angle eyepieces have come down in cost in the last year or two so you might be better off getting a wide angle eyepiece for visual work and an f/3.3 for CCD work.
3-5. The astrometric eyepiece IMHO is the one to get of the three. I don't have one myself but Dave L has one and after looking through it, it's got everything you'll ever need for measuring and centering purposes. For it to plug into the LX90 you'll need the APM - accessory port module. Basically it's an adapter that allows connection of a reticle eyepiece and/or autoguider to connect into the LX90. For this reason I haven't bought an astrometric eyepiece.
www.optcorp.com/product.aspx?pid=319-327-331-2300
6. Necessary for long exposure photography. However, for a narow FOV, you'll get a reasonable enough exposure without field rotation. What sort of exposure times are you thinking of? I have only put my 300d onto my scope a couple of times. I tried 30sec exposures and had no sign of field rotation in any part of the frame. As the 300d has a significantly larger chip size than the DSI, the DSI should IMO get several minutes of an image without any field rotation. My advice - don't buy the wedge unless you absolutely need it due to field rotation.
7. Not essential for the mo IMHO. The LX90 has a different size ope at the back which would negate some of the benefits of a flip mirror or OAG. Try without it first. Then, if you see a need for it, go for it then. It will only help with focusing, not with guiding.

Don't buy them all together, even if you can afford it. Get one at a time, learn how to use it and then proceed to the next step.

As for problems centering the DSI, use the High Precision mode when slewing to targets. This will put a bright nearby star in the FOV of the camera. Center it innthe frame of the camera and then press ENTER. Now it'll slew a short distance to the DSO in question.

Make sure you have programmed the rate of rotation of the gears in the LX90. Thi is under "ALT/AZ ratios" or something like that. This will help with gotos.