I think Rodenstock will coat lenses, only thing is turnaround time is not that optimal.
I think Rodenstock will coat lenses, only thing is turnaround time is not that optimal.
Might be something special to see Rodenstocks's reaction if you send in one of Mark's 2F99c specials for their premium multicoating. Could ask for mounting on a Sinar DB board in order to use the auto aperture feature of the Sinar shutter as well, taking full advantage of the myriad and mysterious optical qualities inherent in Mark's new optical system concept. Now there would be a conundrum for the mighty Rodenstock, might further extend their turnaround time a bit (or trigger an immediate event in the return post from the good wizards at Rodenstock).Originally Posted by Dave Wooten
I think Rodenstock will coat lenses, only thing is turnaround time is not that optimal.
Yours in mirth and admiration (much more the latter),
Larry
^^^ They would probably just grin and take his money.
Just like my old girlfriend...^^^ They would probably just grin and take his money.
"I love my Verito lens, but I always have to sharpen everything in Photoshop..."
How would one go about measuring the aperture of these? Just estimating?
It has something to do with diameter vs. FL but I can't remember the formula. I'll bet Mark knows.
Pretty easy, really:
1. Hold the lens in front of a white wall or sheet of cardboard and focus on something far away. Measure the distance from the lens to the wall. This is the focal length. (You can also measure from the lens to the ground glass if you have it on a camera.)
2. Measure the diameter of the lens.
3. Divide the focal length (1.) by the lens diameter (2.), and the answer is the f/stop!
Example: if it's ten inches from the lens to where the image focuses on the wall, and the lens is two inches in diameter, divide ten by two. You get five. It's an f/5 lens.
"I love my Verito lens, but I always have to sharpen everything in Photoshop..."
Aha, math to the rescue! I knew it was a ratio of some kind but I didn't know it was that simple.
Alright, so I dropped by my local dollar store and grabbed the only remaining glass-lensed magnifying glass in the shop ($1.50). I've fabbed up a lensboard and mounted it on the 4X5. It looks to be a 250mm lens with a 90mm diameter - and unless my calculations are terrible that makes it almost exactly a 250mm f/2.8! It's swirly as heck and the coverage seems massive, although I wouldn't say it's sharp in the corners, haha! I'll post some pics when I get some shots taken, hopefully this evening as I've really got no way of using a hat-shutter in broad daylight with an f/2.8 lens.
Wonderful project. However, I think it is incorrect to call these "soft focus" lenses. Soft focus lenses are soft across the entire field (caveat: the center may be relatively sharper than the edges). We need another term for lenses that are not sharp outside of an inner circle - something like "grad-focus lenses".
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