Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-08-2008, 07:11 AM   #1
Senior Member




Join Date: Mar 2008
Location: Madison, WI
Posts: 270
50mm f1.2

So I have a question... the lens that came with the K1000 film body. Is this the same lens people pay big money for? I mean some people are getting a K1000 body with the 50mm F1.2 from ebay for like $100.00. ( I have been watching) and other auctions with just the 50mm f1.2 have gone for $250.00! I was wondering if the K1000 "kit lens" is different. Did Pentax make 2 50mm F1.2 that looked the exact same?

04-08-2008, 07:13 AM   #2
Veteran Member




Join Date: Feb 2008
Location: Toronto
Posts: 3,915
the old kit lens was 1:2 i.e. F2
a lot of people confuse 1:1.2 to 1:2
04-08-2008, 07:16 AM   #3
Veteran Member
Gooshin's Avatar

Join Date: Sep 2007
Location: Toronto, the one in Canada.
Posts: 5,611
there are two 1.2 lenses

those that are f1.2 (one point two), or, 1:1.2

and those that are f2.0 and are supposed to be written 1:2 but since people are sneaky or just stupid they write 1.2 instead, tricking people into clicking on their sale adds.

the original k1000 kit lens was a 50 1:2 (which is an f2.0)

a real f1.2 will typicaly go for around 500 bucks, if you can find one for 250 that doesnt have something horribly wrong with it... GET IT.



also this is why when browsing ebay its best to look at what the image shows rather than what the ad shows then contact the seller to get clarification, lots of sneaky people on ebay.

i remember someone was selling "a picture" of a playstation 3 for nearly full price.... and people bid because they dont read between the lines.
04-08-2008, 07:25 AM   #4
Veteran Member
aegisphan's Avatar

Join Date: Nov 2007
Location: New Mexico
Posts: 815
By the way, Gooshin, I passed up the deal on the K50/1.2. If you're still interested, you should contact the seller.

The Pentax 50/1.2 has two variants: the K version, and the A version. They've the same optical design. The K has 8 blades, while the A has 9 blades. The A seems to be harder to find and fetching around $550. The K is easier to find, so it hovers around $350.

04-08-2008, 08:17 AM   #5
Senior Member




Join Date: Mar 2008
Location: Madison, WI
Posts: 270
Original Poster
is the f2.0 a good lens on the digital bodies? how many stops am I loosing by getting the f2.0 vs the f1.2? Forgive my ignorance to aperature stops, always stuggled with that! I DO know that the smaller the number the more light and better bokeha (misspelled).
04-08-2008, 08:21 AM   #6
Veteran Member
Gooshin's Avatar

Join Date: Sep 2007
Location: Toronto, the one in Canada.
Posts: 5,611
you're thinking of it the wrong way

you are not losing anything with the 2.0

2.0 is already pretty darn fast, but thats not the point.

depth of field while using anything less than 2.8 is ridiculously thin, this means that you cant just go around snapping pictures of stuff

if you shoot people at 1.2, you can go so far as having their noses out of focus while having the eyes in focus.


me personaly i just want one so i can say i that i have it, but my "need for fast glass" subdued after i realized that actualy shooting at such wide apertures degraded the quality of my work!.

something to think about....
04-08-2008, 08:23 AM   #7
Veteran Member
jshurak's Avatar

Join Date: Jul 2007
Location: philadelphia
Posts: 627
QuoteOriginally posted by madisonphotogrl Quote
is the f2.0 a good lens on the digital bodies? how many stops am I loosing by getting the f2.0 vs the f1.2? Forgive my ignorance to aperature stops, always stuggled with that! I DO know that the smaller the number the more light and better bokeha (misspelled).
I have the 2.0. First lens I used. Its decent and solidly built but you're losing probably 3 stops with the f/2.

Keep in mind that the DOF for the 1.2 is razor thin and difficult to control at close range.

Have you considered the less expensive (and waaaaay easier to find) 50mm f/1.4?
04-08-2008, 08:32 AM   #8
Pentaxian
Oldschool's Avatar

Join Date: Jun 2007
Location: Central NJ
Posts: 1,276
I believe that there is one full stop between f2.0 and f1.4. So, it's more like 1.5 stops between f2 and f1.2 (I think).

04-08-2008, 08:32 AM   #9
Senior Member
Groundloop's Avatar

Join Date: Aug 2007
Location: Toronto, Canada
Photos: Gallery
Posts: 236
QuoteOriginally posted by madisonphotogrl Quote
is the f2.0 a good lens on the digital bodies? how many stops am I loosing by getting the f2.0 vs the f1.2? Forgive my ignorance to aperature stops, always stuggled with that! I DO know that the smaller the number the more light and better bokeha (misspelled).
Your losing between 1 1/3 and 1 1/2 stops going from an f1.2 lens to an f2.0 lens. The meaning of the f numbers get a little ambiguous at that end of the aperture dial depending if your using a 1/3 stop or 1/2 stop scale. Couple that with manufacturing variances you might even find an f1.4 lens that's nearly as "bright" as an f1.2 lens.

But I digress.

The old manual lenses work fine on DSLR bodies, with a few limitations. Obviously they're manual focus only, and if the lens doesn't have the 'A' setting on the aperture ring, you have to use stop down metering via the Green button, and you're restricted Av or M exposure modes only. And spot metering.

You might want to look into getting the FA 50mm f1.4. Awesome lens with all mod cons (less quick shift). Just my 2.
04-08-2008, 08:44 AM   #10
Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 715
f stops go 1;1.4;2;2.8 etc So 1.2 to 2.0 is 1.5 stops.

But as has already been pointed out f2.0 is already fast. Use the lens and i am sure you wont feel it lacks ability to create shallow dof.

the f2.0 is not as appealing to buyers as the 1.7 or 1.4 in the "K" and M series , but that has little to do with its optical quality which is reputed to be as good as the faster lenses.

use it and enjoy it.
04-08-2008, 08:58 AM   #11
Veteran Member
aegisphan's Avatar

Join Date: Nov 2007
Location: New Mexico
Posts: 815
jshurak is right. Stop of light is measured based on area of light getting in. At f/1.2, the area diameter is ~42mm, while at f/2 the diameter is 25mm. That is a 1.68 ratio. 1.68^2 is roughly 3 stops (~2.8).

DOF depends on several factors, and one of them is subject distance. If you stand far enough from the subject, you would get a comfortable DOF. For portrait, your aim might be for creativity purpose.

Optically speaking, both of the K and A 50/1.2 are fine lenses. They might not be as good as the 50/1.4 when stopping down to f/8. But from f/5.6 to f/1.2, their performances are equivalent.
04-08-2008, 09:08 AM   #12
Senior Member




Join Date: Mar 2008
Location: Madison, WI
Posts: 270
Original Poster
QuoteOriginally posted by aegisphan Quote
jshurak is right. Stop of light is measured based on area of light getting in. At f/1.2, the area diameter is ~42mm, while at f/2 the diameter is 25mm. That is a 1.68 ratio. 1.68^2 is roughly 3 stops (~2.8).

DOF depends on several factors, and one of them is subject distance. If you stand far enough from the subject, you would get a comfortable DOF. For portrait, your aim might be for creativity purpose.

Optically speaking, both of the K and A 50/1.2 are fine lenses. They might not be as good as the 50/1.4 when stopping down to f/8. But from f/5.6 to f/1.2, their performances are equivalent.
wooooo... way to technical..
04-08-2008, 10:08 AM   #13
Loyal Site Supporter




Join Date: Sep 2006
Location: Bronx NY
Photos: Gallery | Albums
Posts: 5,599
QuoteOriginally posted by aegisphan Quote

*snip*

Optically speaking, both of the K and A 50/1.2 are fine lenses. They might not be as good as the 50/1.4 when stopping down to f/8. But from f/5.6 to f/1.2, their performances are equivalent.
Actually, I disagree. My "K" 1.2 is a better lens than my FA 1.4. I have both and shoot both frequently and I get better results with my 1.2. Sean Carpents did an exhaustive study of all the 'fast 50's' and came to the conclusion that the A 1.2 was the best of them all. I don't have the link here at my office but if you do a search of this forum I'm sure you'll find the posts. It was an excellent comparison piece.

NaCl(the only way you will get my 1.2 is if I'm dead)H2O
04-08-2008, 10:16 AM   #14
Senior Member
Groundloop's Avatar

Join Date: Aug 2007
Location: Toronto, Canada
Photos: Gallery
Posts: 236
QuoteOriginally posted by aegisphan Quote
jshurak is right. Stop of light is measured based on area of light getting in. At f/1.2, the area diameter is ~42mm, while at f/2 the diameter is 25mm. That is a 1.68 ratio. 1.68^2 is roughly 3 stops (~2.8).
I'm sorry, but I have to disagree. The difference between f2.0 and f1.2 is not 3 stops. Using your calculations, the difference between f2.0 and f1.4 would be 2 stops, when thru experience we all know it's a 1 stop difference. If you don't believe me, watch what happens to your shutter speed in Av mode when you change aperture from f2.0 to f1.4 and vice versa. This web site has A Tedious Explanation of the f/stop
04-08-2008, 10:26 AM   #15
Veteran Member




Join Date: Dec 2006
Location: Outside of Philly
Posts: 1,564
Groundloop is correct
Full Stops go 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
50mm, body, f1.2, k-mount, k1000, lens, pentax lens, people, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wanted - Acquired: Pentax FA-50mm 1.7 or F-50mm 1.7, Sigma 50mm EX 1.4 vtqanh Sold Items 1 11-03-2010 04:24 PM
For Sale - Sold: SMC Takumar 50mm 1.4 / Pentax-A 50mm 1.7 / Pentax-M 50mm 1.4 (US) JP_Seattle Sold Items 3 09-02-2010 06:17 PM
For Sale - Sold: Pentax *ist DL, FA 50mm f/1.4, DFA 100mm f/2.8 macro, DA 18-55mm, A 50mm f/2.0 chemxaj Sold Items 14 05-31-2010 09:34 AM
For Sale - Sold: F 24-50mm 4, A 24-50mm 4, M 35mm 2, M 50mm 1.4, A 35-105mm 3.5, A 70-210mm 4 raybird Sold Items 7 08-29-2008 01:06 PM



All times are GMT -7. The time now is 08:31 PM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top