Help - Use of Lens for widefield with ASI 1600mm-c

[halli]

Hi

I want to try widefield using  a  camera lens - an old manual focus prime lens ie a  200mm F4 SMC Takumar   and the 1600mm-c with an ATIK EFW2 filter wheel.  

First problem is to mechanically screw everything together  ie working out how to connect the lens to the filter wheel.  The lens I want to use has a M42x1mm thread which I believe I will need to convert to a M42 T thread.  I already have a M54 to T thread converter for the filter wheel (scope side).  I think I can get hold of an M42 to M42 T adapter on ebay.  

Next issue is to ensure the lens will focus !  

Am I right in assuming that as long as the distance from the lens base to the 1600mm chip is less than the distance when it is used in an old  Pentax camera  for infinity focus  - I will be ok ?  

I have currently about 17mm from  the ASI chip to the filter wheel which is 22mm thick making 39mm and I need to add the adapter distances to the lens from the filter wheel.  However, don't know what the max distance would be between the lens base and the focal point for an old Pentax lens like the above.  Can anyone help with this please ?

Final issue is mounting the arrangement !  ZWO do a holder ring accessory for attaching the camera via a 1/4 inch photo thread and I guess the lens may require supporting as well.  

Any views on how a good mounting can be achieved ?

Sorry if I have interrupted the sequence of fine images but thanks in anticipation for any help with this.

 

 

[ecuador]

The M42 lens flange distance is 45.5mm. If you had the ZWO EFW, you would use one of these adapters, with an inexpensive M42 to EOS ring and be done. But I don't know if the ATIK EFW is the same width.

[halli]

Hi ecuador - thanks very much for you response and info.    

 Is the distance you mentioned which I guess is from the chip to the lens flange that for a Canon lens or does the lens type not matter ?  Sorry about the additional question but I am new to the use of lenses !