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11-15-2009, 03:23 PM   #16
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The complete brochure is attached in pdf. I scanned it into pdf with Acrobat 8.1. These Focal lenses in the brochure are K-mount.

These lenses function like M series lenses. They support open aperture metering on the K series bodies and M series bodies for example the same way a Pentax M 28mm f2.8 lens would.

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File Type: pdf Focal Brochure K mount.pdf (726.1 KB, 2331 views)
11-17-2009, 04:02 PM   #17
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That's really great! Good information and my 2x is even in there. Thank you!
Ole had said that the zx-50 wasn't compatible with the lenses pre-dating the "A" designation. Do they work ok in manual? I haven't tried the 135 focal or the 50mm chinon on it yet.

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11-17-2009, 08:39 PM   #18
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The problem is that the ZX50 has the "crippled" KAF mount. If it had the "crippled" KAF2 mount, you would be able to use it with the M and earlier series lenses.

For a summary of mounts and bodies that have them etc., take a look at this.

Summary of the K-Mount Evolution, Names, and Features
03-04-2013, 03:24 AM   #19
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Makinon production by the way.

03-04-2013, 05:04 AM   #20
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QuoteOriginally posted by jonhock Quote
I have an "Auto Chinon 1:1.9 50mm" and a "Focal MC AUTO 1:2.8 135mm: lens in Pentax k Mount.
My question is- what is auto about them? I've used both on my k1000 in manual (of course) for years but on my recently acquired ZX-50, nothing special seems to happen.
Since I haven't a clue, I am posting this note.
Thank You
On this lens it means automatic aperture closing when shooting. If you go back through the history of lens development,

- the first slr lenses were manually operated apertures.
- Then they came up with auto aperture which allowed focusing wide open, and would stop down the aperture to shoot.
- Then they developed open aperture metering
- this was followed byAUTO aperture control, which allowed the body to control the aperture setting of the lens directly

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