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  #21  
Old 28-10-2018, 07:01 PM
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xelasnave
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Thats easy to gear from up to five to one is easy with pulleys bike gears or wood ...depends what you have on hand.
Have you a design in mind.
Fram motor mounting turntable...maybe temperature control?
Do you need to watch temp with prolonged polishing or grinding?
The glass much pick up heat ...build in a peltie device in the turntable☺
Must be a concideration in final finishing..you would polish to suit a temp that you will image at I expect ...I dont know but I would polish at that temp..what do others think who know what they are talking about☺
Alex
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  #22  
Old 28-10-2018, 07:05 PM
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I have been thinking of doing a 2.8 in anticipation of getting one of those curved sensors some how..should ask zwo if they have in mind this arrangement...but those sensors should make a hand made mirror more viable you could think.
Alex
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  #23  
Old 28-10-2018, 07:12 PM
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I would love to try fitting a curved piece of glass straight on the sensor of a old dslr and see if that could work inconjunction with a hand made mirror.
You could probably test this with a lens flat one side and concave on the other...sit it on and you could get an idea but making a lens to cover the whole sensor would be a challenge...a square lens...but could coma correction for a short fl be made that simple ... be fun playing around if you could get a round lens from surplus shed...are they still selling?
Alex
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  #24  
Old 29-10-2018, 08:17 PM
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Another idea Logan.
Build the frame onto an old fridge or something you can use to capture water etc...U assume there could be times where a waste management could make life more pleasant.
Alex
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  #25  
Old 29-10-2018, 08:23 PM
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Canon apparently have a curved sensor to suit 1.2 fl and they are seeking folk to test it...try a letter...I will put up my 12 inch for a blank...imagine a 12 inch like that...short tube for a start☺
Alex
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  #26  
Old 29-10-2018, 09:17 PM
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Lognic04 (Logan)
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You know what would be cool, configurable curve, like the sensor detects the lens or you input it manually and it automatically curves - now that would be awesome!!
Yeah, waste management is gonna be tricky!!!
I have been working with the awesome David Campbell who had lended some of his engineering skill to help
I have started learning CAD to aid in design!
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  #27  
Old 29-10-2018, 09:32 PM
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Quote:
Originally Posted by Lognic04 View Post
You know what would be cool, configurable curve, like the sensor detects the lens or you input it manually and it automatically curves - now that would be awesome!!
Yeah, waste management is gonna be tricky!!!
I have been working with the awesome David Campbell who had lended some of his engineering skill to help
I have started learning CAD to aid in design!
That is an original idea.
A great idea ..it really is...and I suspect it will come to pass and when it does be silently content that you had that idea.

I think the problem these curved sensors may present is a need to be made to match a specific fl.
Not a problem so much for astro photography but in other areas that could be a major problem.
I am not up to date they may have a way around the prblem but your idea if they could do that ....mmm nice challenge for us...how to make a sensor that will comply to a command for it to curve...how to do that...I know..you get that wire that grows with current...a very small web an the well suspended somehow...first problem is how to make it flexible...maybe the material ...only way around is a round sensor as if round you could possibly distort it to various fls.

If you had a pressurised chamber you could geometricly distort it I think.

Alex
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  #28  
Old 29-10-2018, 09:56 PM
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Heres one☺
It does work apparently ...simeone said they use it with exray scopes when I ran the idea some place years ago.

But draw a parabola on paper so you get a wine glass extent.
Say our glass on the paper 150mm high...at the top "rim" of our wine glass we cut say from the top down 50 mm could be bigger...but to get the idea...takw our ring and work outchow to collect the light not bouncing off and back from the mirror but glacing at a fine angle...the idea is that it may be better☺
I wonder..
Alex
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  #29  
Old 29-10-2018, 10:19 PM
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Lognic04 (Logan)
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Hmm, I wonder if having a lens simply the opposite curvature of the mirror would correct curvature? This is your number one enemy at fast speeds
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  #30  
Old 29-10-2018, 10:41 PM
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Thinking more the curved sensors would have to dish out whereas what they are working with is dished in...need to think about it.
Just trying to avoid dragging all my gear upstairs and actually doing something.
I wonder could you grab a sensor out of and old dslr and heat it and bend it☺
Microwave should do it☺
I still think a piece of glass to shape could be fitted to a sensor and maybe work.

Alex
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  #31  
Old 29-10-2018, 11:29 PM
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And with a curved sensor a sperical mirror may be better...
Thats something to think about...but should be much easier to get right ...
.mmmm
And all this from some one who hasnt adjusted their reflector since purchase☺
Ask your helper what he thinks about building a vacuum chamber and mirroring set up.
Alex
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