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Focal reducers and a LX200 12"GPS

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#1 greg

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Posted 17 June 2008 - 01:00 AM

Hey all,

I just picked up a Meade LX200 12" F/10 and I would like some input on focal reducers. I really want to make this scope work with the MallinCam so I can build an OBS and be able to broadcast more often. If this scope won't perform the way I want, then up for sale it goes....

So I'm using a MallinCam Color Hyper. I tried my MFR-3 and 20mm of spacers and found that I couldn't even come close to framing M51...I could get most of the main galaxy or half of the main galaxy along with the smaller galaxy.

I would like to run the scope as fast as I can, and if possable still use a diagonal.

I own an MFR-3, 25mm of spacers, Meade 3.3 and a 6.3

I am open to buying other focal reducers if need be..
MFR-4 ???

So what combo of focal reducers, and spacers will help me achieve the maximum useable focal reduction?

Thanks
Greg

#2 smokin oakum

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Posted 17 June 2008 - 06:42 AM

Greg, I would say go with a Hyperstar and all your problems will be solved, but as of now it doesn't look like they offer one for the 12" Meades. If you add too many rings and reducers I'm afraid you might start running into a lot of vignetting and that to me is worse than having a poor FOV!

If it were me I guess I'd go with the advice you gave me, and get the C14 with Hyperstar.

Just a thought.
Neil

#3 smokin oakum

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Posted 17 June 2008 - 07:49 AM

Greg, here is a design for a BYO that you might find interesting.

Neil

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#4 smokin oakum

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Posted 17 June 2008 - 08:01 AM

And here is one with dimensions

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#5 greg

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Posted 17 June 2008 - 10:36 AM

Hey Neil,
Your right they don't make the hyperstar for the 12" Meade.
I got a really good deal on this scope so I just need to get the maximum usable focal reduction to see if I will be happy with it. I'm not thinking I'll be able to get down to F/1.8 but F/3 would be nice... Too much light pollution at my house for F/1.8 anyway :O)

I can't afford a C-14 with Hyperstar (Too much light pollution at my house anyway) so that's why I'm trying to make the LX200 12" work...

I like the design of the roll off dome, Great if I lived at a darksite, but for me rolling the dome off would defeat the whole purpose of having a dome... Where I live I would need the Dome to shield from wind and light pollution.

Back to focal reduction... I talked to Jack and he told me he had heard (if I understood him correctly) that someone used a Meade 6.3 before a 1.25 diagonal and then used an MFR-3 .... Anyone try this ???
What would the F/Ratio end up being?

Are there any other combo's that would yield usable focal reduction??? :question:
If so, what would the final focal reduction end up being?



Greg :imawake:

#6 smokin oakum

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Posted 17 June 2008 - 01:31 PM

Hey Neil,
Your right they don't make the hyperstar for the 12" Meade.
I got a really good deal on this scope so I just need to get the maximum usable focal reduction to see if I will be happy with it. I'm not thinking I'll be able to get down to F/1.8 but F/3 would be nice... Too much light pollution at my house for F/1.8 anyway :O)

I can't afford a C-14 with Hyperstar (Too much light pollution at my house anyway) so that's why I'm trying to make the LX200 12" work...

I like the design of the roll off dome, Great if I lived at a darksite, but for me rolling the dome off would defeat the whole purpose of having a dome... Where I live I would need the Dome to shield from wind and light pollution.

Back to focal reduction... I talked to Jack and he told me he had heard (if I understood him correctly) that someone used a Meade 6.3 before a 1.25 diagonal and then used an MFR-3 .... Anyone try this ???
What would the F/Ratio end up being?

Are there any other combo's that would yield usable focal reduction??? :question:
If so, what would the final focal reduction end up being?



Greg :imawake:


Wish I could help with the reduction question, but I have never owned a SCT before, and have no experience with diagonals.

As to the roll off dome, it is intended to have the best of all worlds. When you have a new moon, and no wind, what could be cooler than rolling off the dome, and seeing the whole sky at the same time? Then when its birighter, and the wind is blowing, you will have the dome. I also priced out what it would cost to build a roll off roof and and ED type setup, and it would run about the same.

I know this is somewhat off topic, but wuth you going from broadcasting with a 30" dob, and now thinking of an OBS, I thought it might be something to also think about.

Neil

By the way, I can do any design you can write out, if you give me dimesions.

#7 greg

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Posted 17 June 2008 - 04:01 PM

If I where building at a dark site I would probably build a roll off dome.
The Moon is not the problem... It's the 4 near by street lights, and the night sky isn't much to look at in my backyard anyway....

If I build an OBS even the slit may need to be baffled down to keep unwanted street light out of the dome.
Also if I have an OBS the 30" will stay in it's trailer unless I'm working on it or I'm at a dark site.

I'm hoping that I can play with the focal reducers I have this Friday and Saturday night... If the scope is up and running I may try and broadcast.... If my computer can keep up.

Greg

#8 Sky Captain

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Posted 17 June 2008 - 04:21 PM

Hey all,

I just picked up a Meade LX200 12" F/10 and I would like some input on focal reducers. I really want to make this scope work with the MallinCam so I can build an OBS and be able to broadcast more often. If this scope won't perform the way I want, then up for sale it goes....

So I'm using a MallinCam Color Hyper. I tried my MFR-3 and 20mm of spacers and found that I couldn't even come close to framing M51...I could get most of the main galaxy or half of the main galaxy along with the smaller galaxy.


Greg,

I have the 10" LX200 and I use a diagonal and the F6.3 reducer and thats all...but your 12" does have more focal length. I also have the F3.3 FR but havent used it yet. I have a lot of LP too, and think that F3'ish may be pretty good.
I have been extremely happy with how that package works!

:penny: :penny:

#9 skyguy88

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Posted 18 June 2008 - 07:34 PM

Hi Greg,

A friend of mine used my .3 focal reducer threaded on to his Mallincam in tandem with a scope mounted .6 FR to get down to about F/1.8 on his 12inch LX 200. He was happy with the combination and bought a .3 FR from Moog in Australia (Webcaddy). I know that when he got the new fr there were some issues with threads. That was a few months ago. I'll try to get an update.

The combination has considerable appeal because you can select from a range of reductions to suit the target that you are looking at. With the hyperstar, it's either F/10 or F/1.8. Some bright objects (M27 and some of the summer mw nebulae come to mind), look better to me on my 8in sct at about f3.

Bill McDonald
Prescott, AZ

#10 greg

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Posted 19 June 2008 - 12:31 AM

Hi Greg,

A friend of mine used my .3 focal reducer threaded on to his Mallincam in tandem with a scope mounted .6 FR to get down to about F/1.8 on his 12inch LX 200. He was happy with the combination and bought a .3 FR from Moog in Australia (Webcaddy). I know that when he got the new fr there were some issues with threads. That was a few months ago. I'll try to get an update.

The combination has considerable appeal because you can select from a range of reductions to suit the target that you are looking at. With the hyperstar, it's either F/10 or F/1.8. Some bright objects (M27 and some of the summer mw nebulae come to mind), look better to me on my 8in sct at about f3.

Bill McDonald
Prescott, AZ



Thanks Bill
That's what I was hoping to hear. If you can find out what was between the .6 and the .3 that would be great... Some Images with that combo would also be nice.

I have a 6.3 that threads onto the back of the scope, and the MallinCam MFR-3 so that should be very close to what your friend used.

I'm hoping to go from scope, to 6.3, to micro focuser, to diagonal, to MFR-3, to MallinCam Color Hyper... In that order... or what ever comes to focus. I really want to be able to use`a diagonal so I don't have to worry about running the camera into the mount near zenith....To use a diagonal I may have to loose the Micro focuser! Hope not!!!

I'm hoping to get to try out differant combo's on Friday and or Saturday Night... If so I will capture some images showing the same object with differant focal reduction.

Thanks again
Greg

#11 cold space

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Posted 19 June 2008 - 01:45 AM

I too am very intrested to see if this works with my 12 inch Lx200R and Mallincam. Have only been using the MFR3 reducer but want more focul reduction if I can and to keep using the diagonal as well. Keep this thread going if anyone can keep providing ideas or experiences that other people have tried.

Matt.

#12 Jack Huerkamp

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Posted 19 June 2008 - 07:36 AM

Witm my C-8 and CPC1100, I always use the Celestron f/6.3 FR on the back of the OTA, add the visual back and diagonal and then insert the MallinCam with MFR-3 and 10mm ER into it. This yields about f/4. I do not use a micro focuser, however.

Jack

#13 cold space

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Posted 19 June 2008 - 07:52 AM

Great Jack, I will give this a try with the Meade 12, might try and get my hands on a Meade 6.3 reducer and give this a try. By the way loving this Mallincam down here in OZ. I lke the way Gavin is piggybacking a refractor on top for getting really wide fields, I will give this ago as well. Tell you what this Mallincam is creating a bit of a stir at our club, I have members wanting to come over and check out what all the fuss is about.

Matt.

#14 greg

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Posted 19 June 2008 - 12:44 PM

I will be trying out every combo of focal reducers I can think of, hopefully this weekend and next weekend, and I'll save and post some images.

I'll pick a large object, not too near zenith in case I need to remove the diagonal, and I'll stick with that object though out the test.

First I'll go with no reducer, then I'll used a 3.3 on the scope (the info that came with the Meade 3.3 claims my scope will be running at F/3 using just the 3.3 and no diagonal...) before removing the 3.3, I'll try using the MFR-3 on the MallinCam with the Meade 3.3 mounted on the scope... Probably won't work but at this point it doesn't cost me anything to try... :O) . I suspect that to get this combo to focus I may need to remove the diagonal ... if it will focus at all ... also the focal reduction may be WAY too fast to be usable....

Next I'll try the MFR-3 with no spacers and no other reducers, then with 25 mm of spacers.

Then I'll try the 6.3 on the scope by itself, then add the MFR-3, then add spacers one at a time....

This test should help me figure out the Max usable focal reduction I can get out of my LX200 12" GPS, as well as other combo's that may work better with differant objects.

This is all in preparation for the Golden State Star Party where I hope to have the 12" set up running the MallinCam with a home made color LCD eyepiece that does not cause any Light pollution to anyone other than the person that is looking into the LCD eyepiece.

If I can make all this come together in the next couple of weeks, then the MallinCam color eyepiece views should be very interesting.

Thanks for any and all input on this little project.
Greg


#15 GrassyPond

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Posted 19 June 2008 - 02:03 PM

Hi Greg,
I am using the MFR-4 with my 12 R and MallinCam. M51 fills about 75% of the screen in this configuration.

#16 cold space

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Posted 19 June 2008 - 05:23 PM

Hi Greg,
Your test sounds great I will be keen to see/hear the results. Thanks for that.

Matt.

#17 Gavin Bray

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Posted 20 June 2008 - 04:38 PM

Hi Greg,
I am using the MFR-4 with my 12 R and MallinCam. M51 fills about 75% of the screen in this configuration.


Joe

Have you tried estimating the focal ratio you achieve with the MFR-4? Is it anywhere near F3.3?

Regards
Gavin

#18 Gavin Bray

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Posted 20 June 2008 - 04:42 PM

Greg

I'd be keen to hear what you estimate the focal ratio is using the various combinations.

I have an MFR-4 that I use with my LX200R and I'm looking for alternatives to try to get down to around F3.3 but the options are very limited.

Regards
Gavin

#19 Gavin Bray

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Posted 20 June 2008 - 04:47 PM

Great Jack, I will give this a try with the Meade 12, might try and get my hands on a Meade 6.3 reducer and give this a try. By the way loving this Mallincam down here in OZ. I lke the way Gavin is piggybacking a refractor on top for getting really wide fields, I will give this ago as well. Tell you what this Mallincam is creating a bit of a stir at our club, I have members wanting to come over and check out what all the fuss is about.

Matt.


A small refractor (I use a 90mm Stellarvue) works very nicely with the Mallincam on brighter nebulae producing a nice wide field and more pin point stars than I get with my LX200R. Still, for most things you can't beat aperture. :)

Regards
Gavin

#20 cold space

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Posted 20 June 2008 - 05:51 PM

Yep,You are right Gavin, can't beat aperature. I will definatly be getting a nice ed type refractor to piggy back ontop of my 12'R mate.Like your wide field shots, you can't beat a bright Neb that is framed with some space around it. Probally look at the new Orion 80mm Eon F6.25 for this.

Matt. :)

#21 greg

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Posted 21 June 2008 - 03:47 PM

OK,
Last night I was able to do some testing.... All tests where done straight through using the Meade Micro focuser and no diagonal.

I 1st picked M51 as a target and found that with the MallinCam and no focal reducers I could get the Main Galaxy without it's smaller companion, or approx. half of the main galaxy and all of the smaller one.

With the Meade 3.3 focal reducer M51 seemed too small....
sorry no images yet ... before I could get my act together M51 went behind a tree...

I found changing out the focal reducers that thread onto the scope a hassle.... Time consuming have to remove and reinstall the Micro focuser and refocus every time...

So, not wanting to end the night without images to share, I chose the Moon cause its easy to find focus...

So here's some of the images starting with the MallinCam and no focal reduction and ending with the Max reduction I could reach with the reducers and spacers I have...Max was reached using the Meade 3.3 on the scope followed by the Micro focuser followed by the MallinCam with the MFR-3 and no spacers.... Wouldn't focus with 25mm of spacers without removing the micro focuser.

Greg

#22 greg

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Posted 21 June 2008 - 03:50 PM

Mallincam Only

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#23 greg

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Posted 21 June 2008 - 03:51 PM

Mallincam & MFR-3

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#24 greg

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Posted 21 June 2008 - 03:54 PM

MFR-3 & 25mm of Spacers

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#25 greg

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Posted 21 June 2008 - 03:55 PM

6.3 only Threaded onto scope

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