|
Forum: Pentax SLR Lens Discussion
02-11-2011, 11:05 PM
|
| |
How does the Vivitar 28/2 A-type compare to the Pentax-A 28/2? The Vivitar is so hard to find, especially when the front doesn't show A like it does on Pentax. "Pentax-A 28mm f1:2"
|
|
Forum: Pentax SLR Lens Discussion
02-10-2011, 10:48 PM
|
| |
Eric, seems the problem with movement is the clicks for each fstop. 3.5, 4, 5.6, 8.... At each fstop it is hard to go over this 'bump' between stops it's smooth like the focus. Wonder why each stop has a grip like that?
|
|
Forum: Pentax SLR Lens Discussion
02-10-2011, 06:02 PM
|
| |
I was just hoping someone made an adapter like the Pentax 110 MFT one which controlled the iris with the adapter. Controlling the aperature with the ring is so clunky. I've used an auto Zuiko before. Almost easy as an A lens.
|
|
Forum: Pentax SLR Lens Discussion
02-10-2011, 05:53 PM
|
| |
Oh, the lens focuses silky smooth btw. Like buttah!
|
|
Forum: Pentax SLR Lens Discussion
02-10-2011, 05:52 PM
|
| |
Have you ever seen an ISCO/Schnieder lens? Wonderful German glass that is on par with Leica. They still make cinema lenses. Guess I'll just have to use it as a specialty lens portrait lens only until I can afford a 135mm A lens. I'll try to upload some pic
|
|
Forum: Pentax SLR Lens Discussion
02-10-2011, 05:49 PM
|
| |
Mike,
The lens is mint. It's just old. That's how it was made 60 years ago. Done on purpose as not to accidently move the aperture ring. It's like comparing the TOS Enterprise to TNG Enterprise. It's all metal and glass. Works the way it did brand new.
|
|
Forum: Pentax SLR Lens Discussion
02-10-2011, 04:57 PM
|
| |
Lowell, no contacts. It's almost 60 years old m42 lens. Just the bare flat metal that I can see. I can see what I can do to upload.
|
|
Forum: Pentax SLR Lens Discussion
02-10-2011, 02:46 PM
|
| |
I know olympus zuikos on a film slr also work like I said. It should be a simple matter of only adding a spring that if pushed opens the aperture fully? Then once released stops down to the set aperature on the ring like it's already doing?
|
|
Forum: Pentax SLR Lens Discussion
02-10-2011, 02:42 PM
|
| |
newarts,
The problem is, I would like a lever to push. That opens and shuts. either a push or release to open to f3.5 and the other to say f16. The lens has only one aperature ring. no auto. no auto lever switch. how do they add such on auto-taks?
|
|
Forum: Pentax SLR Lens Discussion
02-10-2011, 03:34 AM
|
| |
Mike,
My 135mm f3.5 ISCO has no such switch :( It's impossible to focus wide and then turn to the aperture I want. It's all metal and very stiff. When I try, the whole camera moves from the effort.Love the lens, has the best warm color and amazing bokeh.
|
|
Forum: Pentax SLR Lens Discussion
02-10-2011, 02:06 AM
|
| |
I would like to focus wide open with my m42s by either pressing or realeasing a 'pin'.I can then immediately meter at my chosen aperature. This would help focus without having to manually turning the ring. Even worse, trying to focus at say f22!
|
|
Forum: Pentax SLR Lens Discussion
02-10-2011, 01:16 AM
|
| |
acrollet,
how much did you pay so I have an idea of what's acceptable?
You have any other A lenses? How does it compare? I have the pentax-a 50mm f1.7. Great lens. Love the A compared to my m42.
|
|
Forum: Pentax SLR Lens Discussion
02-09-2011, 05:57 PM
|
| |
rp,
So the big green A is the only way to know? Whenever I see a k or ka mount vivitar on ebay only the front with the lens information has a picture. Very rarely does a seller show a picture of the f-stop scale showing the A.
|
|
Forum: Pentax SLR Lens Discussion
02-09-2011, 06:54 AM
|
| |
But isn't MTF more accurate than lp or dpi? I have a crt projector which can show all 1920x1080 pixels of an hd signal. But so can any 1080p digital like DLP. Every single DLP, even the $100 Walmart special, though, will kill my crt for MTF.
|
|
Forum: Pentax SLR Lens Discussion
02-09-2011, 06:42 AM
|
| |
kh,
35mm film according to the DCI (digital cinema initiative) group claims 4096 (4k) wide digital projectors are equal to 35mm movies. That would be 2,890 dpi. Very close to your 2,700 dpi.
|
|
Forum: Pentax SLR Lens Discussion
02-09-2011, 04:59 AM
|
| |
How do you know if one of these lenses has an A setting? Any of the f2 or f1.9 have A? I'm trying to find an A f2 or faster lens 24mm or wider by any maker. Only found a zuiko and these that can work, period, on a pentax in some way
|
|
Forum: Pentax SLR Lens Discussion
11-15-2010, 09:13 PM
|
| |
results! :( That's really lame the old top model 35mm models could do that sort of thing but a fancy digital with all the bells and whistles can't. Especially when Pentax brags about how it can use its old mounts.
|
|
Forum: Pentax SLR Lens Discussion
11-15-2010, 09:11 PM
|
| |
Douglas:
So that was my problem? The camera won't meter automatically in Av mode with K and M lenses and then stop down based on the lens ring? You have to do it? I thought that since the k7 was so advanced it'd do that on it's own. But I was getting funky
|
|
Forum: Pentax SLR Lens Discussion
11-14-2010, 03:30 PM
|
| |
I love you Pentax for making the better mount!
Oh yeah, I'm on Boost Mobile. I get unlimited voice and text. But, unlimited doesn't mean unreasonable. So more than the twitter posts is abusing my 'unlimited'!
|
|
Forum: Pentax SLR Lens Discussion
11-14-2010, 03:27 PM
|
| |
not using the right term. What I mean is the lens aperture can't move with the m42 lens. So the camera can't try any auto so it does the correct metering. Unlike with the K and M which can move. Apparently have Mr cripple K-mount and aren't playing nice.
|
|
Forum: Pentax SLR Lens Discussion
11-14-2010, 03:24 PM
|
| |
Jolepp, Whatever is going on, the camera is ignoring the aperture at the final stage with my k7 and wasn't taking the correct picture. The only way I was getting correct pics was in M with stopdown metering using the green button.
I know I'm probably not
|
|
Forum: Pentax SLR Lens Discussion
11-14-2010, 03:20 PM
|
| |
newarts,There's tons of K and M glass I'd love to get.But I just couldn'd get then to work like they do on a K1000 35mm.On my k7 I was only able to use them in M with stopdown metering or in Av with real funky always wide open.The camera wouldn't close it
|
|
Forum: Pentax SLR Lens Discussion
11-14-2010, 03:03 PM
|
| |
with my camera and not how to use K and M lenses? Or maybe the lens was broken? But that's how the wonderful crippled k-mount handles the k/m lenses?
|
|
Forum: Pentax SLR Lens Discussion
11-14-2010, 02:56 PM
|
| |
I knew the only way to get K and M lenses to meter was to put them in M mode, set the aperture on the lens, hit the green button and snap the pic. Which is why I use m42 lenses which allow Av mode since they stop down on the fly.
Unless I was doing
|
|
Forum: Pentax SLR Lens Discussion
11-14-2010, 02:53 PM
|
| |
won't move the lever on the lens. That's what confused the hell out of me by what Lowell said. He made it sound like to me M and K lenses were working like A lenses but just setting the f-stop on the aperture ring rather than the camera dials. But to the
|
