Meade 200mm ACF v Vixen VC200L

mick pinner · #1 10-07-2009, 07:53 PM

looking for opinions from the optical gurus or people with experience of either of these scopes. any thoughts on which one should be a better option for astrophotography and why. thanks.

jjjnettie (Jeanette) · #2 10-07-2009, 08:35 PM

My next scope will be the Vixen.

Hagar (Doug) · #3 10-07-2009, 09:48 PM

WOW, difficult question. I have a Vixen VC200L and can only speak of my experience.
The scope is a very well made and optically stable instrument made mainly for imaging. It has a built in field correction lens which produces almost perfectly flat fields. It doesn't have a front mounted corrector plate to frost over although I have had a couple of frost ups on the secondary mirror but this was easily fixed with a dew shield. The scope does suffer from large difraction spikes from the overly thick spider but good collimation helps this small problem. The focuser is not the greatest focuser and at the moment there is no alternative available although I believe one is being made at the moment. The mirror is fixed so no mirror flop problems.
Overall this is a great little imaging instrument which performs very well with medium sized CCD's or DSLR's for imaging and it also has a dedicated reducer which drops the FL from 1800mm to 1260mm at F6.4 with the same flat field.

I would still consider this an excelent imaging scope but would also be looking at the 10" GSO or 8" GSO RC's as an alternative particularly after the results Paul Haese has had with his. Then again he has replaced his focuser and it doesn't have a dedicated FFlattener as yet and appears to require some form of field corrector. I think Paul uses a Tak TSAor TOA field flattener to correct the field rotation.

Again a hard question and really a matter for personal choice. Check out some images from them all and see what you would be happy with.
This scope has served me very well.

mick pinner · #4 10-07-2009, 09:59 PM

thanks Doug, l don't know why people have an issue with the corrector plates dewing up, l put a dew shield on my LX200 and never dewed up once and l do like the idea of a closed optical system, less contamination of the primary.
probably the one draw back for me is the diffraction spikes although l could learn to live with them.
both can be brought back to around f/6.3 with focal reducers so this evens out which makes the decision harder because both scopes have good and bad points although l am leaning slightly to the Meade.
as for the GSO R/C's l just don't see the advantage given the after sales modifications needed to fix obvious problems that should have been rectified before release.

Gama · #5 10-07-2009, 10:35 PM

The Optics on the ACF are pretty good.
I have the RCX-14, and images are as flat as the CDK i have, and as sharp too.
You really need to see the optics in real life to appreciate the image quality.
The vixen also has great optics as well, so really come down to your preferences.

Theo

mick pinner · #6 10-07-2009, 10:52 PM

thanks Theo. appreciate the comments.

Terry B · #7 10-07-2009, 11:30 PM

I've owned my VC200L for many years. I haven't looked throught an ACF so can't comment on it.
I now use my scope only with a camera attached. Having never used anything else I didn't understand all the hassles others have with coma and needing field flatteners etc.
The VC200L has round stars to the edge of a 35mm film frame.
When I did try imaging through an APO refractor I then realised how good the VC200l is. The refractor has better contrast but needs a field flattener. This is a major hassle.
I like the diffraction spikes and they are a great focus aid.
Visually the diffration spikes arn't noticeable. Contrast on planets isn't great but I have only compared it to a 14" celestron that does show planets better. My 127mm refractor is no better on planets visually than the VC200l.
Good luck deciding.

Tandum (Robin) · #8 10-07-2009, 11:51 PM

I initially got my vixen to solve weight problems with an heq5 mount, it only weighs 6kgs. I don't have a problem with the focuser, mine has a 10:1 knob fitted and I found that the 2 tiny grub screws on top of it are there to adjust for any issues with tension and slop.

marki · #9 11-07-2009, 02:12 AM

I have a 10" LX200R/ACF. Nice flat fields, nice sharp optics, mirror lock and plenty of aftermarket gear available eg focusers, reducers etc. Same as you Mick, I have never needed any more then a dew shield to hold the dew at bay so I am not sure what all the fuss is about although the air is pretty dry over here. Only problem is its weight, its a heavy tube for its size. I guess it really depends on your mount. As has been mentioned here I would also be looking at the GSO RC's as they are a nice scope (yes I have looked through TrevorW scope) for about the same price as the Meades. Vixen I have no idea, never even seen on in real life.

Doug, I am pretty sure Moonlite make focusers for the vixen tubes and there must be others e.g. Feather touch?????

Mark

Alchemy (Clive) · #10 11-07-2009, 08:27 AM

had the vixen ..... sold it.

fine if you are weight limited. blocky stars due to large spidervanes.

as for the meade offerings stuart (rat ) gets excellent results with his 10 inch.

on a personal note i wouldnt buy either.

gbeal · #11 11-07-2009, 09:37 AM

I'm sort of with Clive here. I have had the Vixen, a couple in fact, and never had the Meade. The newer ACF are getting very good reviews however.
The one thing that I would not enjoy with the Meade is the excessively long (for me) focal length, and the only real way to tame this is the reducer, which is as bad as a corrector on the refractor argument.
The VC200L at 1800 is about as long as I need, but like others found the blocky stars, and spider vanes not for me.
The focuser on the Vixens left me cold as well, and no, right now there isn't really an after-market alternative, although there is the odd murmur of one soon. The problem (I know I pulled it all apart to see if I could do it) is the front section of the focuser draw-tube has the correction lens system built in, and this would need to be done with whatever replaces it.
In the end I settled on a Maksutov, so I still have the potential for dew, and it is heavy, but for visual as well as imaging I am liking it. Each to their own, all are good.
In respect of the thrust of the original post, Mick I reckon you could be happy with either or any, and really it is fun to try differing scopes, settling on one that suits after trying a few. The one thing that is apparent from your sig is the longer focal lengths, for galaxies etc, and the two scopes you mention will do that admirably, each with their own benefits and disadvantages.
Gary

marki · #12 11-07-2009, 09:47 AM

Yeah you are right Gary, the Moonlite focuser option is for the VMC260L. I wonder if Ron would do a custom flange for the 200 ???

Mark

gbeal · #13 11-07-2009, 10:49 AM

Mark,
I am sure Ron would he is that sort of guy, and IIRC Starlight were thinking of looking at a fix as well. I looked at it with the Vixen in one hand, and the Feather Touch in the other and decided that without a lathe I was stumped. Not rocket science, but difficult without the tools and knowledge. The RoboFocus is another alternative.
Gary

Paul Haese · #14 11-07-2009, 01:18 PM

ACF gets my vote, purely on the basis of the lack of blocky shaped stars. I have looked through one and they are very nice. Get around the dew problem and you should be happy.

The problems with the RC have been fixed and the new 10" will not have them. However, that is not the question being asked.

Everything depends on what focal length you want to operate at. Long focal lengths are good for galaxies. Medium you can do most nebula and a lot of galaxies. The ACF can be converted to do both with a ACF reducer. The standard one is not made for the ACF from what I have read and understand.

Best of luck with your selection.

mick pinner · #15 11-07-2009, 04:42 PM

thanks for the input guys, Paul, l cannot seem to find reference to a specific ACF reducer.

Gama · #16 11-07-2009, 06:03 PM

Many use the AP reducer, but you mainly want a reducer with no flattner.
I use the Lumicon Giant reducer on my RCX, it does over correct a little, but start are still pretty good, and reduces my scope to f5.5 .

Theo

marki · #17 11-07-2009, 07:42 PM

Quote:

Originally Posted by mick pinner

thanks for the input guys, Paul, l cannot seem to find reference to a specific ACF reducer.

As Theo said the AP works well. Paul I don't know where you got your info from but the standard SCT reducers work with the R/ACF scopes as well. I have used them a few times without too much fuss.

Mark

Tandum (Robin) · #18 11-07-2009, 10:42 PM

Quote:

Originally Posted by Paul Haese

The problems with the RC have been fixed and the new 10" will not have them.

Off Topic.. Paul, have they got them to balance without hanging weight off the front?

coldspace · #19 12-07-2009, 11:17 AM

I have been using the optec 3.3, 5 and F7 reducers on my 12 inch LX200ACF. They are great reducers and although pricey work a lot better than the cheaper ones I have tried.

Regards Matt.

Paul Haese · #20 12-07-2009, 03:48 PM

The info I got from CN during conversations with Jerry Wise and it seems one you check with the techs the standard corrector is not designed for the ACF. Certainly many other RC reducers would work, everything depends on the metal back distance really. It has to be right to over correct the stars which are typically flat near the edge of the field without correction.

Robin, I did not have this problem at all. I used a longer dove tail bar and that solved any balance issue. Every telescope has balance issue, imagine putting an SBIG with eight hole filter week on an FSQ? You need to counterweight this at the front too. So just a longer bar is the answer to the problem..