screw fit v k fit
Posted 16/06/2009 - 10:58 - Helpful Comment
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You are correct.
The original Pentax screw thread was a 42mm diameter screw thread mount. (I'm ignoring a previous very very old mount to avoid complication.) This was introduced with the Pentax camera of 1957, one of the first with a fixed pentaprism finder.
This mount served well, but in 1975 was superceded by the K mount, a faster to use bayonet mount of 45mm diameter. This increased diameter made possible new and exciting lens designs such as the 50mm f1.2. It is still used today, albeit with the addition of all the electronic contacts.
This means that all Pentax K bayonet lenses are useable on all Pentax K bayonet bodies. There are exceptions to this, and qualifications. For example, newer lenses may be for digital only (reduced image circle would cause vignetting on film bodies) and lenses with no aperture ring need a body that can control the aperture. Even so, almost everything can be used, with limitations in some cases.
The screw thread lenses can also be used, via the Pentax Adapter K, in Av and M modes only.
That's the simple version of the tale, and if you search the forum or ask a specific question then any exceptions that may be relevant to you can be revealed!
The original Pentax screw thread was a 42mm diameter screw thread mount. (I'm ignoring a previous very very old mount to avoid complication.) This was introduced with the Pentax camera of 1957, one of the first with a fixed pentaprism finder.
This mount served well, but in 1975 was superceded by the K mount, a faster to use bayonet mount of 45mm diameter. This increased diameter made possible new and exciting lens designs such as the 50mm f1.2. It is still used today, albeit with the addition of all the electronic contacts.
This means that all Pentax K bayonet lenses are useable on all Pentax K bayonet bodies. There are exceptions to this, and qualifications. For example, newer lenses may be for digital only (reduced image circle would cause vignetting on film bodies) and lenses with no aperture ring need a body that can control the aperture. Even so, almost everything can be used, with limitations in some cases.
The screw thread lenses can also be used, via the Pentax Adapter K, in Av and M modes only.
That's the simple version of the tale, and if you search the forum or ask a specific question then any exceptions that may be relevant to you can be revealed!
Best regards, John
Posted 16/06/2009 - 11:13
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Great thanks for confirming - takes the confusion out of which lenses are compatible. I saw some lenses for sale on eBay stating K mount and screw fit which I thought was strange.
Posted 16/06/2009 - 11:38
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72dessa wrote:
I saw some lenses for sale on eBay stating K mount and screw fit which I thought was strange.
That is very useful information. It means that the seller has no idea what he is talking about, and should be avoided!I saw some lenses for sale on eBay stating K mount and screw fit which I thought was strange.
G
Keywords: Charming, polite, and generally agreeable.
Posted 16/06/2009 - 13:01
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George Lazarette wrote:
G
Or you might pick up some good gear very cheap 72dessa wrote:
I saw some lenses for sale on eBay stating K mount and screw fit which I thought was strange.
That is very useful information. It means that the seller has no idea what he is talking about, and should be avoided!I saw some lenses for sale on eBay stating K mount and screw fit which I thought was strange.
G
shim
Posted 16/06/2009 - 14:29
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Ironically, the older K mount lenses (K and M series) aren't as easy to use on a modern DSLR as the (older still) M42 screw-mount lenses (mainly down to the somewhat erratic metering with the older K mounts - nothing that's insurmountable but they may take a bit of practice).
I have bought and sold many K/M and M42 lenses and the screw-mount versions do tend to hold their value a little better when compared like-for-like. Of course the later K mount lenses (A series onwards) give you more options and tend to fetch quite a bit more money accordingly.
I have bought and sold many K/M and M42 lenses and the screw-mount versions do tend to hold their value a little better when compared like-for-like. Of course the later K mount lenses (A series onwards) give you more options and tend to fetch quite a bit more money accordingly.
Joining the Q
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13 posts
17 years
If it's a screw fit lense then there are adapters available. Have I misunderstood this or am I correct in my understanding?
thanks