M42 thread on ZWO asi 224

[Steve Clay]

Will a M42 thread Pentax lense fit a ZWO camera?

Sounds a silly question but I know threads can have different characteristics.

Thanks

Steve

[Kev M]

Both will be 42mm threads but the pitches are different 0.75mm & 1mm.

If you screw them together they may lock up and/or damage the threads, so NO would be the best advice.

Adapters are available to convert between them

 

 

[michael8554]

You also need the lens to be no more than 45.46mm from the sensor to achieve infinity focus.

45.46mm is the backfocus of Pentax M42 threaded lenses.

You can get infinity at less than 45.46mm, but more than 45.46mm and the lens focus will run out of travel.

Apparently the ASI 224 sensor is 12.50mm into the body, leaving a 32.96mm gap to the lens.

So the 28mm extension from a set like this may get you close enough, then you need a M42 1.0mm to 0.75mm converterno thicker than 4.96mm :

https://www.ebay.co.uk/itm/Macro-Extension-Tube-Ring-Mount-Adapter-For-M42-screw-mount-Zenit-Zeiss-Pentax/230998682313?hash=item35c8982ac9:g:5x8AAOxyhodRuW8m

Michael