Meade 3.3 focal reducer

[2STAR]

hi, Meade 3.3 focal reducer, if anyone spots one of these on there travels could you let me know please, they were discontinued some while back I believe, but maybe someone somewhere has one they don't use and would like to sell.

Thanks

Eric

[cjdawson]

Good luck on that.  Although, they do come up from time to time on EBay.  I managed to get one a few months ago, complete with the CCD adapter that screws onto the visual back.   One day, I'll get time to play with it using my DSI.

[Davey-T]

I think the only reason they made them to start with was for the original CCD sensors which were so small they were trying to squeeze the image onto them, not really needed nowadays and focussing was finicky.

Dave

[2STAR]

On 12/2/2016 at 17:40, cjdawson said:

Good luck on that.  Although, they do come up from time to time on EBay.  I managed to get one a few months ago, complete with the CCD adapter that screws onto the visual back.   One day, I'll get time to play with it using my DSI.

Hi, I have one on loan that I am using at  present with the Atik infinity and  evo 9.25 at f5.

Focal length of meade 3.3 is 85mm

45mm spacing to get f5 ( take into account the Infinity back focus of 12.5mm (13mm), so spacing required is 32.5mm to get f5 (courtesy of Hiton CN)

ERIC

 

 

 

 

[2STAR]

On 12/2/2016 at 18:21, Davey-T said:

I think the only reason they made them to start with was for the original CCD sensors which were so small they were trying to squeeze the image onto them, not really needed nowadays and focussing was finicky.

Dave

Hi, there is mixed opinion on the Meade 3.3, but it works ok with the infinity 2/3 chip. 

[Davey-T]

It doesn't increase the FOV  just fits more of the available FOV onto the sensor by altering the angle of the incoming image which makes focusing harder.

Shouldn't be any different to the 6.3 and a bigger sensor

Dave

[Dave In Vermont]

Here's a link to an article on focal-reduction which references the Meade 3.3. Though written around MallinCam video-cams, the principals shown are pretty much universal:

http://www.mallincam.net/uploads/2/6/9/1/26913006/focal_reduction_for_dummies.pdf

Good luck in your hunt for the 3.3.

Dave

[2STAR]

On 2/22/2016 at 19:28, 2STAR said:

hi, Meade 3.3 focal reducer, if anyone spots one of these on there travels could you let me know please, they were discontinued some while back I believe, but maybe someone somewhere has one they don't use and would like to sell.

Thanks

Eric

Thanks I now have one (albeit on loan)

Eric

[ollypenrice]

I've tried the 3.3. They just cover the tiniest of chips so they are only of use in very specific applications. If only getting an F3.3 scope were that simple!!

Olly