I'm looking for refractor field flattener/reducer recommendations

[[1ponders]]

I'm looking at getting a field flattener for my Orion 80ED refractor (among other things) in the next month or so. What flatteners are available that would be suitable for this scope?

[[1ponders]]

I've come across these:

Televue 1.1X field flattener (http://www.optcorp.com/product.aspx?pid=660&kw=field%20flattener&st=2)

Williams Optics 2" APO 0.8x Focal Reducer/Field Flattener (http://www.optcorp.com/product.aspx?pid=6962&kw=field%20flattener&st=2)

Williams optics Megrez and Zenithstar reducers for 80mm scopes (http://www.iankingimaging.com/show_products.php?category=65&offset=10&offset=20)

Vixen Focal Reducer for FL80S (http://www.buytelescopes.com/product.asp?t=71&pid=4807&m=)


Vixen 0.67x Focal Reducer for ED81S/ED103S/ED115S (http://www.buytelescopes.com/product.asp?t=71&pid=11099&m=)

comments?

[Gama]

Well, i use the Next Gen Maxfield reducer (0.5). This actually works very well.
Its really made for the SCT scopes, but i tried it on my 102mm f5 refractor which i normally use as a guide scope, and with the SXV-H9, the image is Magic.

[Dennis]

Hi Paul

Just be aware that some of the Vixen products tend to use Vixen specific threaded things, such as 64mm and 60mm rings to attach to their telescopes, which are non standard and usually a little expensive to buy.

Cheers

Dennis

[Garyh]

Hi there,
How about the mogg focal reducer? I think they are made just for the ED-80s
They are just a 2 element design so don`t really know how good a pic you get through them?..
http://www.moggadapters.com/
cs Gary

[gbeal]

Good question Paul, and one most seem to be asking. I recall Striker doing the same exercise, so maybe he will suggest something.
What I would suggest is you grab one of each, including the Mogg, and do a quantative test. That way we will all know. I want one for the Tak for example.

[acropolite]

Here's some stuff on the NextGEN that gama is taking about. http://www.optecinc.com/optec_028.htm

[Striker]

The optec reducer has a flat field diameter of 18mm....may be pushing it with a DSLR chip....fine for small chipped CCD's.

Do you really want to reduce a 600mm focal length scope to .5x with some vignetting.
.8x williams optic looks pretty good.
I would give the mogg reducer a go.
I think you want more flatning then reducing is this right Paul.

[[1ponders]]

One of the things that concerns me the most is finding one that will give a full illumination of the 300D chip. I know Stricker used the Lumicon Giant Easy Guider, but I don't want the off axis ability nor the additional expense that comes with it.

I like the sound of Steve Moggs one. Anyone heard any reviews on it.

Gamma if the Next Gen is an SCT reducer for f/10 and works with the orion, what are your thoughts on the current Meade focal reducers? Is it likely they would be suitable?

[[1ponders]]

Yes Tony, I'm more after the flattening effect rather than the reducing.

[acropolite]

I thought I had read somewhere that the Meade f6.3 F/R can be used on an ED80, how suitable is it?? Here's some info on a similar f6.3 SCT reducer and use on ED80's, but the reduction is only from f7.5 to f5. Its down the page a bit http://www.clearvueoptics.com/newest_products.htm

[[1ponders]]

I've just remembered reading somewhere, cant find it though, that there is a problem reaching focus using the meade, maybe why there is an adapter that goes with the one you linked to Phil.

[[1ponders]]

I just tried the Meade 6.3 in the Orion and no way was it going to come to focus. I didn't have enought infocus. That was using this setup

[gbeal]

Maybe try a shorter T adapter, the thing that takes the reducer SCT male thread to a male T thread. Even just hold the Canon, with T ring in place, against the reducer (also in place in the scope), see if it focuses??

[[1ponders]]

I've been looking into that Gary. Just don't seem to have the right length adapter with C thread one end and T thread the other. I might just bite the bullet and contact either Steve Mogg or Clear View optics.

Gama do you need an special adapter to get your Next Gen reducer to reach focus in the Orion?

[acropolite]

I bought a T adapter heaps shorter (to clear the LX90 forks with my camera) than yours from scopestuff, Baader make an even shorter one than the one I have. I seem to remember reading that the 6.3 FR needs a certain distance extension between it and the camera for correct operation (perhaps for 35mm only). I know Peter in hobart successfully uses the much shorter baader with the 300d. There's an image of the 6.3 FR, baader T adapter and 300D on his site (http://www.users.bigpond.com/lansma/art_prime_focus_imaging.htm). I have heard of people using the Meade reducer on the ED80 so it can't be that difficult.

[[1ponders]]

The "normal" distance Phil, form front reducer element to imaging surface is 105mm. Increasing the distance "increases" the reducing effect and shortening "lessens" it so I believe. f/ratio reduction is not what I'm look at so this might be a solution for me. I'll check out the site you've linked to

[[1ponders]]

I think the Baader mount he uses is very similar to the one from Clear Vision. It isn't a straight through tube but is infact a lense system to still achieve the full 6.3 reduction. It's hard to tell from the picture but it looks similar

[JohnG]

Hi Paul

I asume that you have had a look here:

http://televue.com/engine/page.asp?ID=169

I notice that they have a distance of 55mm to the focal plane using a normal T-thread. From the photo's I have seen they seem like they would be OK for you short focus refractor, and in 2" format as well.

Cheers

JohnG

[[1ponders]]

Yes I did have a bit of a look at them John, but they were starting to get up into the "choke" factor for me atm, which is why I was looking at just the 1.1x TV flattener (see link at the top) even though it will slow the scope down.

I must admit the ClearVue option is looking tempting. I could try the setup as is and with my meade FR and sell one or the other depending on results.

[h0ughy]

I just happen to have the anteres 2" camera adapter and a celestron f6.3 focal reducer, I will give them a go!

[[1ponders]]

Please do h0ughy, I'd like to know how you go getting focus using the Canon

[h0ughy]

right the first images are with the focal reducer on the Skywatcher ed80 pro using my canon 300d mod, so I apologise for the images now. Taken looking roughly east away from the afternoon sun, they are of a communications tower, a tree and the roof of my house. I will also include a wide field shot to show where they were taken.

Until I saw the post by Phil I had no idea that I could use the focal reducer with the adapter. I have two, the Antares one and a Orion one, they are identical! Oh and I left on the IR/uv filter.

[h0ughy]

now I will say focus was extremely easy to achieve with the reducer in, and I had room to move from a far focus to a near object, and the draw tube was not too far out, maybe an inch-1,5 inches.

but without the reducer it was to the full extent of the draw tube plus a little bit of the adapter moved. So there is a huge difference in focus positions:lol: :thumbsup: . I am keen to give this a go soon too!

[h0ughy]

I also apologise for the terrible images

[Striker]

I still cant see any slab going down for the observatory Houghy.

Thats the same T-adapter I use...much better then the skinny sct adapter.

[h0ughy]

You are too cruel Tony:P , I hope ice freezes over the corrector plate :D (not really but that's about as nasty as I can think at the moment for that cruel and insidious comment you made:( , I am working on it though, the pier on on the drawing board and the steel is hot:thumbsup: ........)

[Astroman]

yeah where is that pier?

By the way I have no idea what you are trying to achieve there with all those gadgets, how do they work under the stars? Any coma, CA etc.........??

[[1ponders]]

Well I've ordered the Orion 2" adapter from Bintel to go with my existing Meade 6.3 FR. I'll post how it goes when it arrives but looking at h0ughys images at least I know it comes to focus.

[acropolite]

Paul, Jim (footprint) has successfully mated the celestron F6.3 to his ED80. (see this thread (http://www.iceinspace.com.au/forum/showthread.php?t=11302)) It may be worth PMing him and asking for details. Also this site (http://www.machunter.org/hapsequipment.html)may give some clues. It appears that the distance from the focal reducer to the focal plane is critical according to this report (http://www.saratogaskies.com/articles/ed80-reducers/index.html).

[Adrian-H]

http://www.saratogaskies.com/articles/ed80-reducers/index.html

havent got around to buying a fr yet, i will get around to it sometime in the future.

0.8x will take you from 600mm f/7.5 down to 480mm f/6, its a difference.

[Gama]

I just used the adapter for the Sbig camera that i had.
Turned out to be close enough to give good results.

Further, the f6.3 reducer also works very well on Newtonians.
I placed mine on my 22" F4.5 and not only did it reduce, but gave a nice flatter image. Mind you i was holding it by hand.. I need to make some adapter for it for a more permanent setup.

[Robby]

I've ordered a WO 0.8x 2" reducer for my 80mm doublet. They are on backorder, but have heard good reports. It will take my f/6.9 to f/5.5 and hopefully flatten the field so I can utilise the whole 300D chip. ATM I get coma in the corners.
Let us know how you get on with the f/6.3 as I have one of those too, but no adapters at the moment.
Cheers

[[1ponders]]

If anyone has with and without reducer shots I'd be interested in seeing them posted here. If enough are posted to give a range of good comparisons, with the links to the suppliers, it could be worthwhile making this a sticky thread for other refractor users to find more easily.

[Karls48]

Hi 1ponders
Here are three pictures of treetops about 1km away. Taken with Celestron 102, 500mm stopped to f8.3 and Gstar camera. First – no reducer then home made 0.75 reducer and Mogg 0.6 reducer. Each needs different combination of T adaptors and the spacer rings to achieve focus. On my GS 150mm f5 Newtonian I cannot get focus with Mogg reducer at all.
Karl

[[1ponders]]

Thanks for getting the ball rolling Karl. :thumbsup:

[gbeal]

Paul,
while the idea is sound, it would be my suggestion to try it on "stars". I had a reducer that looked for all money to be great in my ED80/840 scope. When Striker was after one I sent it to him, and it was awful, especially on the outer edges. Maybe it was made for a smaller chip than a DSLR, who knows. What I am suggesting here is that astro usage places greatly more stress on the optics than terrestrial.

[Karls48]

Omega Cen. images with Celestron 102 500mm f5 and GStar camera. Singe exposure 0.64 sec. All images taken with same setting on wobbly undriven tripod. Sorry about focus, the Celestron got awful focuser.
Mogg 0.6 FR, Home made 0.75 FR and no Focal Reducer.

[el_draco]

Greetings folks. I am also trying to work out the best way to go with a filed flattener. I've got a Black Diamond 120mm refractor and love it to bits but I'm now slowly developing (ha ha) an interest in imaging.

I'm currently wading through the morass trying to determine the best way to go with a CCD camera and field flattener to suit. Guhru's most welcome to enlighten me...

[Hagar]

Hi Paul, The WO PFlat 2 reducer flattener is designed for a DSLR size chip but again requires spacing of about 55mm from the chip.
This works very well with my Sywatcher ED80 (same as the Orion).
Available from www.andrewscom.com.au (http://www.andrewscom.com.au)

P-FLAT2 NEW 2" APO field flattener, 0.8x reducer, for refractors. Includes 2" adaptor. $249.00