A Ken Rockwell lens and focusing quote

kshapero

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"An advantage of the older Nikons is that their focus screens are optimized for fast lenses like f/1.2 and f/1.4, so you can see the really shallow depth-of-field and actual bokeh of these lenses through the finder. Newer cameras, like the FM2 and DSLRs, are optimized for slower zoom lenses, which makes their finders much brighter with slow lenses, but unable to show you the shallower depth of field of which faster lenses are capable. Think I'm kidding? Press the depth-of-field button to stop an f/1.4 lens down to f/2 or 2.8 on most modern cameras and you will see no difference in depth of field or brightness!" Ken Rockwell

Is this true? What about RF's? Are my ZI and FM3A obsolete even before I bought them?
 
My Nikon D200 has a DOF preview button. BTW those old Nikon F's were great. No need to join a gym, they weighed a ton.
 
But then again he followed it up today with a heading "HDR that doesn't suck" which included a link to typically garish HDR images.
That's Ken, as soon as he writes something interesting, he then goes and writes something wacky, but he is entertaining.
 
A plain ground glass screen is the least intrusive on the wqy the picture looks but dark and not easy to focus. A screen made up of little tiny "microprisms" snaps in and out of focus a lot more decisivly but the prisms are set at an angle optimized for a particular f-stop. If you use a smaller aperture the prisms start to black out, giving the finder image a shimmering effect. Essentially, if the prisms are set for an f/5.6 lens aperture they start looking funky if you stop down more. If you open up to f/2 or f1.4 or whatever YOU'RE STILL FOCUSING AT f/5.6 because that's the part of the lens that the screen is reading. Nikon used to offer various screens for different lenses.

http://thepriceofsilver.blogspot.com
 
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I couldn't see bokeh with my Canon 40d and 50/1.2L but I can see it with a Pentacon Six and CZ Jena 80mm/2.8.
 
Is there any 35mm SLR higher viewfinder magnification than a OM-1 at x0.92 with 50mm ?

The aberrations of the 50mm f/1.2 full open unfortunately lower the contrast a bit so focusing is not as crisp as with the cheap f/1.8. But for visualizing wide open out-of focus effects of a fast lens it's outstanding.
 
A plain ground glass screen is the least intrusive on the wqy the picture looks but dark and not easy to focus. A screen made up of little tiny "microprisms" snaps in and out of focus a lot more decisivly but the prisms are set at an angle optimized for a particular f-stop. If you use a smaller aperture the prisms start to black out, giving the finder image a shimmering effect. Essentially, if the prisms are set for an f/5.6 lens aperture they start looking funky if you stop down more. If you open up to f/2 or f1.4 or whatever YOU'RE STILL FOCUSING AT f/5.6 because that's the part of the lens that the screen is reading. Nikon used to offer various screens for different lenses.

http://thepriceofsilver.blogspot.com
Nice to know that after 35 years behind the viewfinder, I am still learning something new everyday.
 
I will categorically state that "bokeh" is a bunch of nonsense. Nobody aside from a few psychotics look at or care what "bokeh" is.

The people who harp about it are parroting nonsense they've read from other dopes.
 
For close-ups or longer tele lenses the brightest and most accurate screen is a plain clear glass, no ground glass or micro prisms, with cross hairs.

As for bokeh, it means something to me. If you can't see it that's really a shame.
 
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I will categorically state that "bokeh" is a bunch of nonsense. Nobody aside from a few psychotics look at or care what "bokeh" is.

The people who harp about it are parroting nonsense they've read from other dopes.

I won't disagree with you. The second most overused word on Internet photography forums.
 
It's just more convenient to say "bokeh" than "The particular way that a given lens renders the out of focus areas". I guess that makes me both psychotic and a dope.
 
It's just more convenient to say "bokeh" than "The particular way that a given lens renders the out of focus areas". I guess that makes me both psychotic and a dope.

I personally love bokeh. When I was a kid I smoked it a lot until those warnings came out. Later I just made a tea out of it but now my teeth are out of focus.
 
This is all very confusing - I read the Dphotoexpert posting.

My undertanding of depth of field, and pardon my lack of technical descriptions, was that light from any given point on the subject, passes thru the entire surface of the lens. if you think of you viewpoint being the surface of the lens, you will be able to see the subject from slightly different angles, from all points on the lens' surface. These rays from the subject, travel thru the various elements and are "reassembled" at the film plane. each point on the film plane is the superimposition of infinite "rays" of light from the subject. the more surface area of the lens, the more overlapping and infinitessimally offset images and angles of the same subject point. the further the subject is away from the designated focus distance, the more these overlapping images diverge. The smaller the aperture, the fewer overlapping images, and the sharper the focus.
Again pardon me for my intuitive but perhaps way off-base understanding.
Now the true depth of field,at the film plane, is set by the focus distance and the aperture, it shouldn't change. The only think I can think of, is that by diverting light to the sensor, depending on design of the mirrors and prism you may get the same effect in the VF as you would on the film/sensor plane when you use a smaller aperture, if live view shows a more accurate DOF, that would imply that the mirror/prism VF effect is not occuring.

I still don't understand why in zoomin with a variable aperture zoom, you don't see the VF darken...

Anyway - can someone explain this to me in short words and simple sentances ?
 
A plain ground glass screen is the least intrusive on the wqy the picture looks but dark and not easy to focus. A screen made up of little tiny "microprisms" snaps in and out of focus a lot more decisivly but the prisms are set at an angle optimized for a particular f-stop. If you use a smaller aperture the prisms start to black out, giving the finder image a shimmering effect. Essentially, if the prisms are set for an f/5.6 lens aperture they start looking funky if you stop down more. If you open up to f/2 or f1.4 or whatever YOU'RE STILL FOCUSING AT f/5.6 because that's the part of the lens that the screen is reading. Nikon used to offer various screens for different lenses.

http://thepriceofsilver.blogspot.com

And the OM system (single digit bodies) offered a wide variety of screens, with screens optimized for wide, standard, telephoto, macro, etc. With the right screen you could avoid the shimmering and blackout effects. Easy to change, too.
 
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