Pentax lens mount question
I want to thanak all of those who replied to my question about getting my Pentax K1000 CLA'd. Now I have a question regarding the lens mount.
On KEH's website, I was looking for a 50 mm lens for my Pentax K1000. The lenses on KEH's site are listed as follows, for example: 50 F1.7 SMC A and 50 F1.7 SMC M. NO mention of the K-mount. What's up? Will these lenses fit the K-mount? I am not familiar with the K-mount and which lenses will fit, and I could used some help. Obviously I am missing something,and I'd hate to order a lens and have to exchange it because I didn't get the model number right in the first place.
Thanks to all who reply.
With best regards,
The short answer is that both are K mount and will work on the K 1000. The A has additional contacts that more advanced bodies use so if you plan on getting another body it might be a consideration.
A good resource for K mount is Bojidar Dimitrov's website.
You should be able to locate used K mount lenses without too much trouble. Although KEH is reputable, you might do better shopping around at flea markets and places like that.
John, Mount Vernon, Virginia USA
Indeed, the no. 1 reference in Pentax bodies and lenses is Bojidar Dimitrov - you'll find there all about Pentax.
Besides that, if you are looking for a 50mm Pentax lens, forget the 50mm f:2 - it has only 5 elements (a shame). On the other hand, the f:1.7 and f:1.4, are all beautiful lenses. And you also can check with other manufacturers like Ricoh who also sold under the label of Sears who made very contrasty lenses (excellent for slides), Chinon (very precise, but somehow technical outputs), Cosina and Vivitar who's 50/1.7 is a beauty (precise, still very gentle outputs). All these made 50mm f:2 and f:1.7 with 6 elements, and f:1.4 with 7elements. For aditional information about K-mount lenses and bodies other than Pentax, the reference is Butkus: http://www.butkus.org/chinon/index.html
All of the pictures I've ever taken with my smc P-M 50/2 look fine to me...
Please forgive the ignorance of my question, but what does the number of elements in a lens do for the quality of the photograph? The only affect I can think of a larger number of elements having is an increase in lens flare...
At any rate, most (if not all) of the Pentax primes are wonderful, and they won't disappoint. Also, if you can find one, an adapter exists that allows you to use M42 (i.e. Takumar) lenses on a K-mount camera. The Takumars (which are the lenses that Pentax made for its Spotmatic line) are just as nice as the K-mount Pentax lenses, if not nicer.
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[ Also, if you can find one, an adapter exists that allows you to use M42 (i.e. Takumar) lenses on a K-mount camera.
Such an adapter opens up a universe of opportunities, since any of the Pentax-Practika screw mount lenses may be used--not just Takumars.
John, Mount Vernon, Virginia USA
Adapters to mount M42 on K-mount are pretty common. I believe B&H sells them, among others. The geometries involved mean that the adapter is just a hunk of metal with a thread inside and a K-mount ring on the outside; no optics are required. One caveat, though: "Automatic" M42 lenses, with the pin that stops down the aperture, don't work well with most adapters, since the adapters don't work that pin. I vaguely recall hearing of an adapter that will stop down the pin, but I don't recall the details, and I could be misremembering.
Be careful with any that you find on ebay or some camera shows. Some do not mount flush like the Pentax version and will not allow infinity focus. The Pentax made versions are best but they are getting hard to find. And no, I'm not selling either of mine......
Originally Posted by srs5694
While beautiful, screw mount lenses (M42) will limit you when focussing and metering: M42 do not meter with the aperture wide open like K-mount lenses. So, you'll have to make the focus with the aperture wide open, than close it manually in order to adjust it with the shooter time. I really don't see an advantage in M42, as they are neither better, nor worser, than K-mount lenses. Maybe cheaper, but with today's drop in prices does this really matter?
To Stevopedia: What do the numbers of elements in a lens count? Well, in 35mm it does a lot. In LF it does far less. Let's put it in another way: what enlarging lenses do you prefer - 4el/tessars or 6el? I also found a 5el enlarging lens, a russian one (Vega), but at least this is a "hot" lens (with 1el of radioactive Lanthanium making it equivalent to 6el lenses) and it is my beloved for portraits. Back to 35mm: if you want to avoid flare, the best is to look for a multicoated lens. Even 4el/Tessars or 3el are giving flare if simple coated. By reducing the number of elements in a lens you do not avoid the flare, but only the image quality. I had the Pentax 50/2, and had to pray for somebody to buy it for 20$ Canadians (12-13$ US at that time). And by that time lenses prices were still high - it was the time when there were no digital cameras over 1MP, and nobody believed in digital yet.
BTW, many M42 lenses are simple or double coated. Some K-mount are too, but far less. Pentax's SMC stays for Super Multi-Coated, and it means 5 or 7 coating layers (7 I think), and this is the best coating system ever done (I mean even today it isn't overpassed by any other manufacturer). But forget about the 50/2 even if SMC...
Last edited by phenix; 05-06-2008 at 12:42 AM. Click to view previous post history.
B&W is silver.
I've also got a Vega 11U enlarger lens. I know of one other FSU/Russian lens that's said to have some lanthanum (the Industar 61L/D, which shipped with later FEDs), but I wasn't aware the Vega 11U (if that's the model you mean) also used lanthanum. I'm curious: Why do you like that lens for portraits?
Originally Posted by phenix