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Stellarvue SVX080T-3SV w/ .74X Reducer-Flattener

astrophotography dslr refractor
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#251 zakry3323

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Posted 26 March 2020 - 05:13 PM

I was at 55.5mm last night and it's ok...still room for improvement. Unfortunately I'm working on trying to adjust tilt in the system and my Gerd Neumann CTU is a bit too thick. Right now the tilt is more annoying for me.

 Capture4.JPG
 


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#252 zakry3323

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Posted 27 March 2020 - 09:43 PM

I had a conversation with Alex at Stellarvue and he let me know that the reducer/flattener decouples with the differently-anodized extension, freeing up an additional 16mm of backspace and allowing enough room for the CTU with the use of a single M48 adjustable extension!

I didn't buy directly for Stellarvue, so I'm not sure if there's any documentation about the reducer/flattener. I didn't see much about it at the website  , but this a game changer for me, allowing me to use tilt adjustment along with my OAG and filter wheel. If anyone knows of any documentation floating around out in the Ether, would you please share it with me? 

IMG_20200327_220907.jpg

IMG_20200327_220935.jpg

I'm not sure if this is a single machined part, or if there's an M48 adapter threaded onto the thicker portion of the tube. I sure hope that it's two parts, but my hands are worn out from removing the extension. I'll stick it in the freezer and think about it tomorrow.

IMG_20200327_220953.jpg

 

 



#253 zakry3323

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Posted 28 March 2020 - 01:33 PM

I often tell people that astrophotography is more tedious than it is "hard". That being said, getting this apart was very hard. I'm going to invest in a good strap wrench and save my fingers next time :)

 

IMG_20200328_142636_resize_41.jpg


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#254 SebaAstro

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Posted 31 March 2020 - 08:56 PM

I often tell people that astrophotography is more tedious than it is "hard". That being said, getting this apart was very hard. I'm going to invest in a good strap wrench and save my fingers next time smile.gif

 

attachicon.gifIMG_20200328_142636_resize_41.jpg

I have the same reducer but after reading your post then I HAVE to try too since I have the OAG and filter well on my imaging train and I didn't realize that i needed to take that spacer off in order to reach 55 mm back focus.

 

I have only one concern: once the extender is removed and then you insert the flattener inside the focuser how to you plan to remove it? I don't see a way to hold it in order to unscrew it back out. 


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#255 zakry3323

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Posted 01 April 2020 - 10:18 AM

I have the same reducer but after reading your post then I HAVE to try too since I have the OAG and filter well on my imaging train and I didn't realize that i needed to take that spacer off in order to reach 55 mm back focus.

 

I have only one concern: once the extender is removed and then you insert the flattener inside the focuser how to you plan to remove it? I don't see a way to hold it in order to unscrew it back out. 

I haven't reassembled the imaging train completely yet, I'm waiting on an M48-T2 adapter to arrive in the mail sometime. 

 

IMG_20200401_105655.jpg

 

My plan is to go from Reducer-->Tilt Adjuster-->OAG-->FW-->Sensor, with an adjustable threaded extension between the OAG and the FW to get the focal distance dialed in. 

 

It's my understanding from my discussion with Alex that the backspace of 55mm is with the extension attached. Removing the 13mm extension gives you that much more space to use for additional or thicker accessories (like my tilt adjuster). I don't know what kind of OAG and filter wheel you're using, but it may not be necessary for you to remove the extension. 

 

To remove the reducer once installed, I'm just using the knurled ring that threads onto the reducer, seen in my photo above. It bottoms out counter-clockwise, so it should provide you a good grip to decouple from the drawtube.  




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