Not the William Optics ZS66

[MarkS]

I found a secondhand Nikon lens in a camera shop at the weekend.  It's a Nikkor 300mm F4.5 AI and it's at least 25 years old.  It cost me £100 but they are quite sought after because of their legendary optics. With an aperture of 66mm(!), focal length 300mm and F4.5, in theory, on a DSLR, it has a specification almost exactly the same as a WO ZS66 + 0.8 focal reducer. 

So, theory into practice, I tried it out last night and even at full aperture the stars were very sharp right into the corners with very little vignetting (note the lens would have been designed for a full 35mm frame).  It's only drawback is that it only works in full manual mode on my camera i.e. no auto-focusing and no metering.  But neither are a requirement for astro-photography.

I'm now wondering if I could attach a webcam and turn it into a guidescope.  I wonder if some adaptor exists ...

[Ian]

I wouldn't guide with it, I'd use it as the main imager. Nice find mate

[MarkS]

Yes, I definitely want to use it as a main imager: what I'd like to do is to piggyback it on the C11.  I can then then use one or the other as main imager and guide.

[JohnP]

Mark - Great find & I don't see why not. If you get yourself a modified webcam you'll also have a reasonable FOV for some of the bigger DSO's.

When I started out the only place you could get adaptors for Toucams etc from was a guy in Australia.. Looks like he is still in business & ahas a whole range of adaptors for webcam to SLR lens etc.. Check this out:

http://webcaddy.com.au/astro/adapter.htm

Hope this helps - John.

[Mike]

Speak with Paul - I know he coupled a Canon lens up to his Starlight Xpress somehow.

[Rocket Pooch]

Hi,

I have a webcaddy adaptor and they are plastic and do not fit very well, I beleieve QSI make high quality metal adaptors, but it willl set you bach £130, ouch..

Chris

[MarkS]

Thanks for the link, John, I've noticed they also do an adapter to use the lens on a Canon EOS.  Chris I think £130 for the QSI is a bit over the top - it's more than I paid for the lens.