Quote Originally Posted by deathrox View Post
Live and learn, no more mirror lens' from now on. I see NO point in making a lens that can't produce a sharp image.

....
I think the term sharp image has different meanings to different people ... but more importantly! an understanding of what the lens is doing helps to assess the lens's ability(or otherwise).

if you don't mind me interloping and posting an image from my Nikkor 500/8 C.
it's an old lens, been beaten about a bit, inferior optic design to most modern lenses, cheap cheery fun lens that produces a unique outcome that not many other lens types can do.

D800E_DSC_0948.JPG
This image is a 50% crop and then resized to 1000pixels for the forum software to accept. Even at a straight out 1000 pixel crop the detail rendered looks OK(enough).

If exif is not in tact, then the specs are D800E, 500/8 model C mirror lens, 1/250s(sorry Lance ), obviously f/8(that's the only option) .. but what isn't obvious in the exif is that this is just after I installed this Dandelion CPU chip onto the lens. So the lens specs in the exif come up as 500mm f/8 G. If you know about Nikon lenses you'll know that the G nomenclature is their second most recent in terms of modernity(and this becomes important .. if you care to read the info below)

As I said earlier the durability of this little Dandelion CPU device is pretty hopeless, but the important feature that it offers is that it almost makes the lens an AF lens.

obviously it doesn't transform a manual focus lens into an AF one(you need a special adapter for that, which you need to hack and .. too long a story to tell here!) .. but back onto what this cpu chip offers.

On some cameras you can set the camera to only make an exposure when focus is achieved. That's the default method that most Niko's come out of the box.
I don't know if this works on a D5500 .. and probably never find out .. but with the chip installed, the camera thinks it's an af lens, and that it's it's autofocusing it. Of course it's not, but as long as the camera thinks it is, this trick works.
Because the camera thinks it's autofocusing the lens, I manually focus the lens. I hold my finger all the way down on the shutter and nothing happens .. but as soon as the camera thinks it's now in focus, as I'm already holding the shutter release down, it automagically makes the exposure the moment focus is achieved.

So the action needed to do all this is a split moment and what woudl be normal operation. Press and hold shutter .. Nothing happens as the there is no focus... I focus the lens as per normal manual focus lens... Nikon's have a rangefinder focus system that works for manual focus lenses .. the instant I fluke focus in my tuning the focus ring the camera snaps the image.

This is only due to the way the Dandelion chip can be programmed to use what's known as focus trap.
There are camera settings that need to be made too, but it's all quite simples.

The only way to get a decently half usable image out of this lens prior to this Dandelion CPU was to focus bracket.
That lil birdy shot was a single exposure. 1 in 3 shots made was in focus, actually I think the other's are just blurry due to slow shutter speed(see! Lance was right )

Like I said before, there are tricks to owning a mirror lens and getting 'satisfaction' from it. Sharpness and intricate detail rendering is not one of the qualities you get this lens for, but with a bit of patience, there should be enough to warrant having one at hand.