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02-16-2010, 04:19 PM   #1
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K200D crop factor

I have recently aquired some M42 lenses, when I fit 50/1.8 to my K200D it asks for focal length to be selected, now my question is, do I select actual or aply crop factor, which I understand to be 1.5
Martin

02-16-2010, 06:11 PM   #2
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QuoteOriginally posted by martc Quote
I have recently aquired some M42 lenses, when I fit 50/1.8 to my K200D it asks for focal length to be selected, now my question is, do I select actual or aply crop factor, which I understand to be 1.5
Martin
Welcome to the forums Martin!
You put in "50"mm
..or is what you have actually is a 55mm lens 'coz I know there is an f:1.8 for the 55mm but not for the 50mm.
02-16-2010, 06:21 PM   #3
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Gerry is right, you enter the focal length which is marked on the lens.

Perhaps more information than you'd want to know but here is an explanation of the "why":

https://www.pentaxforums.com/forums/pentax-lens-articles/90477-crop-factor-fo...ield-view.html
02-17-2010, 03:24 PM   #4
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Thanks for prompt replies,
Ole:- I checked out the link Re field of view, it confirmed my understanding of things,
but it might be a silly question, but are all lenses of say 2.8 / 50 for example all the same field of view regardless of manufacturer.

GerryL:- the lens I have is a pentacon auto 1.8/50

02-17-2010, 05:26 PM   #5
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QuoteOriginally posted by martc Quote
Thanks for prompt replies,
Ole:- I checked out the link Re field of view, it confirmed my understanding of things,
but it might be a silly question, but are all lenses of say 2.8 / 50 for example all the same field of view regardless of manufacturer.

GerryL:- the lens I have is a pentacon auto 1.8/50
There are no silly questions!

Yes, all 50mm lenses will have the same field of view on the same camera.
02-17-2010, 06:11 PM   #6
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The reason for my question Re:- field of view, is that I want a wide angle lens, wider than the 18-55 that came with K200d, any suggestions, I dont mind a M42 manual lens
martin
02-17-2010, 06:45 PM   #7
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QuoteQuote:
martc: The reason for my question Re:- field of view, is that I want a wide angle lens, wider than the 18-55 that came with K200d, any suggestions, I dont mind a M42 manual lens
martin
Martin, do you have a preference for a zoom or prime for the WA?
02-17-2010, 07:26 PM   #8
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I would prefer Prime
martin

02-17-2010, 08:33 PM   #9
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The primes available from Pentax are the DA 14 mm and DA 15mm Limited, expensive, and not that much wider than your 18mm. You may get more bang for the buck from the DA 12-24mm zoom, or the DA 10-17mm fisheye zoom - both those lenses are among my favorites.

Lenses designed for film (like M42 manual lenses) are hard to find any shorter than 15mm unless you go for a fisheye. Pentax didn't make any film lenses shorter than 15mm, perhaps other manufactures did.

Btw, a really nice and excellent prime fisheye is the A 16mm f/2.8. But again, I think one of the above mentioned zooms will be the better option.

The lens review database is a good place to start your research:

https://www.pentaxforums.com/lensreviews/index.php

Last edited by Ole; 02-17-2010 at 08:40 PM.
02-17-2010, 09:17 PM   #10
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Martin, all of the Pentax lenses Ole suggests are excellent. And I agree with him that, among those choices, the Da 12-24mm zoom would serve you best because it would provide even wider focal lengths. But, if you are budget conscious, and still want excellent image quality, the Sigma 10-20 is an option too. See, for example:

PentaxForums.com Third-Party Pentax Lens Review Database - 10-20mm F4-5.6 EX DC HSM (AF Lens)

And if you want to see pics with the lens from our Sigma 10-20mm Club, you can sift though here. Best of luck to you.

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/84539-sigma-10-20mm-club.html
02-18-2010, 08:18 AM   #11
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QuoteOriginally posted by martc Quote
I would prefer Prime
martin
I really don't get WA primes, well maybe the 15mm 'cos it's so small but optically the zooms are as good if not better outside the extremes of their range and about the same price.

The 12-24 is as good as the 14mm at 14mm, just a stop slower. The 10-20 is cheaper but agan seems comparable at 14mm to the prime.
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