Meade Focal Reducer arrived

Striker (Tony) · #1 21-02-2005, 12:49 PM

Ok it arrived first thing this morning from the states....well packed and very happy......I just dont what I am going to use it for or what it does....hehe

Paul.....expect this question Saturday Night....lol

Striker (Tony) · #2 21-02-2005, 01:43 PM

Ok...is their anyway to connect the Meade Focal Reducer 6.3 to the Peterson Eye-Opener?

westsky · #3 21-02-2005, 04:06 PM

How big is the Peterson eyeopener?

rumples riot · #4 21-02-2005, 04:18 PM

No problem ask away. Answer, it screws directly onto the rear cell of the scope. It will give you wider angles of view and is great for use on prime focus shots. It will speed up your exposure times and divide them in half. Does that answer it for you?

Striker (Tony) · #5 21-02-2005, 04:25 PM

Yes but the eye-opener is a larger diameter....so it looks like I have to put the original back on.

[1ponders] (Paul) · #6 21-02-2005, 06:15 PM

Hang on Tony. You should have recieved two adapters that go into the back of your Microfocuser. One is for the Stardiagnal and the other is for the focal reducer. I wondered about this as well so I posted a question at the yahoo LX200 group and this is what they suggested. For visual the people who responded said that it was fine to go straight after the telescope but for photography to avoid some issues (they didn't exactly specify what) to put it after the microfocuser. The adapter I'm talking about is threaded one end and is labelled "L" in Fig 6 on page 13 of your LX200 manual.

Good luck

Striker (Tony) · #7 21-02-2005, 07:28 PM

Paul...that works using the adapter to connect after the Micro-focuser...but then it leaves a thread as per diagram L which I can't connect my 2" diagonal......does that mean I need to get a threaded 2" diagonal.....I cant see anymore adapters to get around this.

I will keep trying and looking.

rumples riot · #8 21-02-2005, 07:37 PM

No Tony now you fit the microfocusor and remove the 1.25" adapter from it and simply slip in the 2" diag in.

Striker (Tony) · #9 21-02-2005, 07:57 PM

I dont use the 1.25" adapter...I have the FR connected to the back of the MicroFocuser as per 1ponders recomendation...but that leaves me with a threaded connection that the 2" diagonal wont fit...I would need a threaded diagonal to fit on the FR.....or am I doing this wrong.....in the Meade Instruction manual page 13 it says as per 1ponders recomendation.

You cant slide a diagonal into the FR...you could only thread it on....?

[1ponders] (Paul) · #10 21-02-2005, 08:20 PM

tony if you want to use the FR for visual work then yes it does go at the back of the telescope first then the microfocuser then your 2" diagnal. For Photography you use the microfocuser at the telescope first then the FR then the Camera. See

rumples riot · #11 21-02-2005, 08:21 PM

Well, what i do is use the adapter straight on the back of the scope, then screw the focal reducer straight onto the adapter. Then I use the threaded adapter ring which is about 10mm wide and put this inside the microfocusor and lock it off with the allen screws. Then I screw this onto the focal reducer. That means that you can now use the 2" throat on the micro focusor to install the diagonal

rumples riot · #12 21-02-2005, 08:27 PM

Actually Paul I use the way I have described for both visual and photographic, so that is just another way of using the focal reducer. Neither is wrong just different uses.

Striker (Tony) · #13 21-02-2005, 08:38 PM

Ok got it.......so really the only way to use it with a diagonal is to screw it into the back of the scope then the Microfocuser....

sorry...just got a bit confused with Paul saying for the FR to put on after the microfocuser for photography.....with photography I was thinking LPI and Toucams....sorry my fault.

Actually Blame Paul (1ponders).....yes its Paul's fault.....lol....striker is never wrong.

So back to my original question.....their is no way I can connect the FR to the Eye-openner...I have to use the smaller and original adapter..

Paul (1Ponders) is not allowed to reply to this post anymore.....hehehe

I am going to give you heaps about this on Saturday paul.....lol

[1ponders] (Paul) · #14 21-02-2005, 09:00 PM

Paul, I'm not sure how this works out using a DSLR or film camera, and I'm sure there are others better versed in this than I am lurking around, but I seem to recall reading in a CN forum that the optimum distance from the last lense element to the CCD chip should be in the range of 109mm to 115mm. (I've tried to find it again but there are so many damn posts over there its like looking for a needle in a haystack when you do a search) I' have come across this though http://webpages.charter.net/tagos/FLR.html . Mind you I like to test these things out myself, not that I don't believe everything that's written on the web, I'm more of what you might call an experiential learner. ie I learn from my own mistakes not others

I might get the opportunity on Saturday night to test out both theories of before and after and compare results.

But Tony I'll let you off easy. The only way I can see to use the FR visually is in front of the Microfocuser.

rumples riot · #15 21-02-2005, 09:30 PM

Paul If you remember those shots I took of M42 and eta carina that were really sharp posted late last year and early this year. These were taken with the FR before the microfocusor. However, that being said, I might experiment myself.

[1ponders] (Paul) · #16 21-02-2005, 11:38 PM

Maybe that's why I'm having trouble getting a good image with my 300D. Maybe the post-microfocuser is for CCD imaging only?

ebob · #17 24-02-2006, 04:29 PM

[quote=Striker]Ok got it.......so really the only way to use it with a diagonal is to screw it into the back of the scope then the Microfocuser....

...

So back to my original question.....their is no way I can connect the FR to the Eye-openner...I have to use the smaller and original adapter..

---------------
Hi Striker,

There is a way to use a focal reducer with the Peterson EyeOpener. You need a female SCT to 2" female eyepiece adapter in order to link the FR to your Diagnal. And fortuantely for you, I have just the link you need! http://www.scopestuff.com/ss_adt2.htm $24USD.

So, for clarity, here's the optical train:

Rear of telescope
EyeOpener
Microfocuser
SC Accessory Adapter (item "L" from manual)
FR
SCT to 2" adapter
2" Diagonal
and away you go!

However... you are unlikely to get exactly the f 6.3 effect from the FR because of its placement and focal length, but you can get pretty close.

The Meade f 6.3 FR has a focal length of 230mm. This means that the nominal reduction to 6.3 takes places 85mm behind the FR. On many 2" diagonals you have internal travel of approximately 90-102mm, and then you have to determine where the field stop of the eyepiece falls in that path (-8mm to +18mm). Most eyepieces have a field stop of about +6mm which gives you an approximate net length of 96-108mm and corresponding reduction to f 5.8 - f5.3 from the optical train effects.

Then there's the change in SCT f ratio due to the mirror travel in the OTA for focus which can move this figure even further. (Meade doesn't release the internal measurements and I'm not doing it by hand...)

Anyway, if you want to use the eyeopener and the FR you can certainly do it.

All my best,

ebob

10" LX200GPS UHTC
StellarView F50
WO 2" Erect Diagonal
yada yada yada

Striker (Tony) · #18 24-02-2006, 04:44 PM

Wow...pretty much a year ago this question was asked.

Mike that must be some kind of record....1 year for an answer....lol

Thanks Ebob but I have seen many scopes since this time a year ago...I dont even own the peterson anymore.