Is the William Optics RedCat 51 worth buying?

Started 4 months ago | Questions thread
mikeyL Contributing Member • Posts: 977
Re: Is the William Optics RedCat 51 worth buying?

little jim wrote:

starman1969 wrote:

I've been after a short focal length refractor for wide field deep space imaging and I have been looking at so many scopes. For a while I have been using standard camera telephoto lenses due to being without a scope for a while.

The RedCat would suit my style of astrophotography more than any other, but I'd like to know if it is worth buying over a similar focal length standard camera lens?

There's no doubt the Redcat51 (250mm/F4.9) would yield fantastic images, even with your full-frame Nikons (most refractors perform best with APSC cameras, FF image circles are hard).

But, given your heavy investment in premium Nikon FF cameras and lenses, I'd recommend seriously considering a premium quality new or used 300mm/F2.8 prime lens, which would complement your 70-200/F2.8 and 500mm/F4. This class of telephoto would give you >4 stops more light and (arguably) better resolution than the Redcat51 with its ~100mm aperture.

But you also don't mention what mount you're using. The saying "put your money where your mount is" applies here.

Committing to the 300/2.8 could put you on the following roadmap (in no particular order):

1) purchase FF mirrorless camera and adapters for best in class Nikkor lenses

2) modify your 800E to astro

3) invest in premium quality equatorial mount

4) think about the manual focus Samyang/Rokinon 135mm/F2 prime to fill out your astro lens collection

5) start saving for a premium quality 600mm/F4!

I've followed the above roadmap (purchased the Sony A7R3 for all-purpose photography, adapted my Sony A7 (Kolari) for AP, adapters for FD and EF Canon lenses, purchased the EF 300/F2.8L UXM (no IS) and FDn 500mm/F4.5L legacy lenses (30 and 40 yrs old respectively) while upgrading my mount from SkyWatcher HEQ5 to iOptron CEM40.

I went through the GAS of considering purchase of a premium quality 5" refractor--purchasing the FD500 and CEM40 cured me temporarily LOL. I'm having a blast with the adapted lens strategy.

Good luck with your choice, you can't go wrong with the Redcat (or its larger aperture siblings).


Jim's advice is spot on - for any deep sky style astroimaging, the mount is absolutely critical for your results. You can have a $20,000 telescope, but if it cannot track the sky accurately, your results will be unusable. So only once you have that figured out should you then see what your remaining budget is for some sort of a telescope or camera lens to use for imaging. Of course, as I stated earlier, for lower magnification and/or faster optics, the tracking requirements are lower than with high magnification or optically slower scopes or lenses. But it is always best to buy more mount than you think you need, as if you stay in the hobby you will likely grow into it with larger scopes or optics in the future that will benefit from its higher weight capacity and better tracking ability



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