800mm Mirror Lens
 

hello, someone of you has tried this disc of a valve on the 5d (with l' adapter nikon-eos)?
Ciao

http://www.amazon.com/Rokinon-Multi-...906433&sr=1-16

Ebay Italy link replaced with Amazon link.

Not that one specifically, but I've shot cats and newts with my 5D2. They all have terrible vignetting and doughnut bokeh, but other optical qualities such as sharpness vary widely. Keep in mind that f/8 on a cat is usually like T/11 or so due to the central obstruction.

An 800mm f/5.6 autofocus lens costs $10,600.
A really good cat, such as the Sony 500mm f/8, costs $600.
This 800mm f/8 costs $200.

So it costs 53 times less. Is the quality 53 times worse? No, it's maybe only 20 times worse, so you do get "more than you pay for".

Here's Ken Rockwell's review of Nikon's 500mm f/8 reflex lens. I presume that it's similar in design to the 800mm lens noted above:

Nikon 500mm f/8 Reflex-Nikkor test Review © 2004 KenRockwell.com

I will post some preliminary test shots I took with the a combo I would have thought was going to be pretty poor. In a howling win, I took a 400mm Vivitar T lens and added a 2x adapter, also by Vivitar. When I could keep the camera still from the wind, I think the images were pretty good, in comparison with shots with telephoto adapters I use to use on my FX1. As I said, I will post some examples this evening..

One this that is clear to me, and I don't not the reason for it, is that any dust on your low pass imager filter is for some reason made more apparent with long lenses.

I know that narrow (high) f-numbers cause dust to become more apparent.

Telephoto footage
 

This is a test using the Canon 5D Mark II, with a Vivitar T system 400mm lens with a Nikon mount. Mounted with a Vivitar 2x adapter bought for $15.00 or so on Ebay. Shot in 30p. Not sure how vimeo will handle change to 24p. But I am tickled that not a lot of CA is showing up. This appears to provide a better image than what I could get out of my FX1 with a teleextender on it.



http://www.vimeo.com/3845090

Thanks for the video, Chris.

That's the neat thing about cats and newts: mirrors reflect all frequencies of light the same way. CA is never a problem on a pure newt, but sometimes the corrector plate (the front element) on a cat can introduce CA.

Of course this Vivitar is your standard run of the mill telephoto. See pic attached