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Flattener for TMB130ss and full frame DSLR

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#1 Phil Hosey

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Posted 02 February 2014 - 04:06 PM

Does anyone know of a flattener or reducer/flattener that will work with a TMB130ss with the FT 3545 focuser and a full frame DSLR? I need about a 42mm corrected image circle right?

#2 David Pavlich

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Posted 02 February 2014 - 04:32 PM

Would this one work, Phil? That full frame chip is going to be tough to cover! This was made for WO's 132, so maybe it could be your reducer.

David

#3 Phil Hosey

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Posted 02 February 2014 - 04:42 PM

Would this one work, Phil? That full frame chip is going to be tough to cover! This was made for WO's 132, so maybe it could be your reducer.

David


David,
I actually have that reducer. It works very well over APS-C sensors, in fact stars are pinpoint corner-to-corner and there is no vignetting. It supposedly has a 50mm clear aperture, but who knows if it is well corrected over the 42mm image circle I'll need. In addition that that, since it uses a T-thread connection to the camera, I'll bet there will be vignetting on a full frame sensor.

#4 Odell

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Posted 02 February 2014 - 05:51 PM

This is the one that was suggested to me with the same basic set up as yours Phil. I can't verify its efficacy but might be worth a look.

https://www.astronom...ro-tech-tmb-...


Ian

#5 Phil Hosey

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Posted 02 February 2014 - 06:51 PM

This is the one that was suggested to me with the same basic set up as yours Phil. I can't verify its efficacy but might be worth a look.

https://www.astronom...ro-tech-tmb-...


Ian


I have that one also. Not sure if it'll cover a full-frame DSLR though.

#6 buckeyestargazer

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Posted 02 February 2014 - 10:11 PM

Hi Phil,
This one TSFlat2,5 is an excellent flattner. The specs say it has a corrected field for up to 55mm sensors. I can't confirm that as I only have a KAF-8300 chip, but that flattener worked very well with my APM115 apo.

#7 David Pavlich

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Posted 02 February 2014 - 10:37 PM

Would this one work, Phil? That full frame chip is going to be tough to cover! This was made for WO's 132, so maybe it could be your reducer.

David


David,
I actually have that reducer. It works very well over APS-C sensors, in fact stars are pinpoint corner-to-corner and there is no vignetting. It supposedly has a 50mm clear aperture, but who knows if it is well corrected over the 42mm image circle I'll need. In addition that that, since it uses a T-thread connection to the camera, I'll bet there will be vignetting on a full frame sensor.


Good point, Phil. If it uses a T-thread adapter, you'll have some pretty hefty vignetting.

David

#8 mfarrell

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Posted 02 February 2014 - 11:58 PM

Hi Phil,

I have the TMB130SS also, and use it with a Canon 5D MkII. For a flattener, I have the William Optics FLT flattener that came with my scope when I purchased it used.
FLT Flattener
The original version has a conical T-thread adapter, which unfortunately does vignette the extreme corners of a full-frame chip. I also noticed that while it is very good with the TMB130SS, the corners of the full frame chip aren't perfectly corrected. I bought several adapters from Teleskop Service to get rid of the T-thread bottleneck, and use M48 thread instead. While I was at it, I stumbled across a different spacing that actually improved the correction to almost perfect. :jump: Now, it looks like the FLT flattener as sold by Agena Astro comes with an M48 thread adapter instead of the old conical T-thread adapter, but I suspect the spacing is optimized for the WO scopes, and not for the TMB130SS. For what it's worth, these are the adapters I purchased:

FT3545 to WO FLT Flattener
M80 to M69
M69 extension + M69 to M48 adapter
I found by removing the 5mm M48 extension that comes with the above adapter, the edge correction improved.

Now, admittedly this is a pretty expensive flattener setup and would cost close to $700. There is another flattener on the market that closely resembles the FLT flattener, in fact it looks like a dead ringer, even down to the suggested spacing and connection threads. :question: It is sold here in the US as the Meade flattener for their Series 6000 130mm refractor and by Teleskop Service as their 3" TS Photoline flattener. Needless to say, it is much less expensive than the WO FLT, but I can't be certain if it is optically identical. Considering it is designed for Meade's 130mm F/7 refractor, it's probably pretty decent at worst and doesn't cost a fortune. You could buy the same adapters I mentioned above and get the unvignetted M48 connection to your camera.
Meade 3" Flattener

The TSFlat 2.5 mentioned previously would likely work well also, but I'm not sure exactly what spacing would be optimal for the TMB130SS and a full frame chip.

As for a reducer/flattener combo, I can attest that the Riccardi 0.75x works extremely well with this scope even to the corners of my full frame DSLR...unfortunately it is an expensive beast. :bawling::tonofbricks: There may be other reducers out there that work, but since a full frame sensor is very demanding, I decided to skip straight to what I thought had the best chance of being successful.

Hope that helps!

#9 Phil Hosey

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Posted 03 February 2014 - 06:39 AM

Thanks for the great info guys.. at least now I know there are some solutions that should work, even if they are a bit expensive.


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