Attaching a star analyser 100 to a dslr lens - cheapest way?

[Helen]

I'm looking for a cheap way to attach a star analyser to a dslr with lens.  I'm trying to put a simple kit together for Uni on a limited budget and the official adapter is £46.  Any suggestions?

Thanks

Helen

[Kev M]

Have a look on a well known auction site ( or similar websites  ) for  ......  58mm to 28mm  Step Down Filter Ring Adapter

Assuming the lens takes a 58mm filter and the analyser is 28mm ( or 28.5mm )

 

 

 

 

Edited September 28, 2019 by Kev M
typo

[Stu Todd]

I bought a spare lens cap to fit the lens I use and drilled a 1.25" hole in the centre. Cost about 4 quid. Worked great! 

[Merlin66]

Helen,

A spare lens cap as mentioned above, centre drilled to 28mm allows the SA filters to be securely  "screwed" into place. the cap can then be rotated on the front of the lens to bring the spectral image horizontal to the chip.

Works well.....

 

[robin_astro]

From my website here

http://www.threehillsobservatory.co.uk/astro/spectroscopy_17.htm

The annoying design of the Canon lenses means the grating rotates as you focus but an empty rotating filter cell from a cheap set of polarising filters

https://uk.telescope.com/catalog/product.jsp?productId=109834

completes the setup, making it easy to rotate the SA (glue the rotating filter cell into the hole in the lens cap and screw the SA into that) Clip on lens caps work best but it can be difficult to find ones where the clip mechanism does not prevent a large enough hole for the SA

Robin

Edited September 29, 2019 by robin_astro
links added

[Helen]

Great - thanks all   (I love this place 🙂 )

Helen