Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-21-2009, 11:00 PM   #1
New Member




Join Date: Oct 2009
Posts: 22
Would this lens fit a K20D?

Would these lenses fit a K20D and could you tell me if they are any good and worth purchasing? I am looking for a wide angle/fish eye lens for landscape photography but as i am just learning don't want to spend a great deal (plus i can't afford to spend much)

Pentax M 1:2.8 28mm Wide Angel Lens - does the M stand for manual focus?

Takumar 1:3.5/28mm Wide angle Lens - Is this manual/autofocus

Asahi SMC Takumar 1:3.5/28 M42 Pentax Lens - Is this manual/autofocus

SIGMA AF 28-80MM LENS FOR PENTAX AF CAMERA

PENTAX TAKUMAR F 28-80MM F3.5-4.5 AF LENS

Many thqanks

10-21-2009, 11:52 PM   #2
Loyal Site Supporter
SteveM's Avatar

Join Date: Jan 2009
Location: Vancouver Island, BC, Canada
Photos: Gallery
Posts: 3,295
QuoteOriginally posted by mattmiles Quote
Would these lenses fit a K20D and could you tell me if they are any good and worth purchasing? I am looking for a wide angle/fish eye lens for landscape photography but as i am just learning don't want to spend a great deal (plus i can't afford to spend much)

Pentax M 1:2.8 28mm Wide Angel Lens - does the M stand for manual focus?

Takumar 1:3.5/28mm Wide angle Lens - Is this manual/autofocus

Asahi SMC Takumar 1:3.5/28 M42 Pentax Lens - Is this manual/autofocus

SIGMA AF 28-80MM LENS FOR PENTAX AF CAMERA

PENTAX TAKUMAR F 28-80MM F3.5-4.5 AF LENS

Many thqanks
First would borrow one of these lenses to see if it is right for you.... Check out the Takumar club thread.....but understand that these lenses take a few manual steps....

Pentax M 1:2.8 28mm Wide Angel Lens - It is manual focus...it's a fine lens if you find it cheap enough but if you want a 28 I would find a 28 3.5 instead. Manual everything including focus. Read about using the green button.

Takumar 1:3.5/28mm Wide angle Lens - Great lens....but it is screw mount (M42) so you need an adapter (buy only an authentic Pentax adapter or you could be very sorry). Manual everything including focus. Read about using the green button. This lens should be fairly cheap.

Asahi SMC Takumar 1:3.5/28 M42 Pentax Lens - One of my favorite lenses. SMC is the coating which helps control light (flare) etc. Manual everything including focus. Read about using the green button. This lens should be fairly cheap.

Older zooms are not as great as older primes.
10-22-2009, 12:53 AM   #3
emr
Guest




mattmiles, you might want to have a look at this:

https://www.pentaxforums.com/forums/pentax-dslr-articles/64298-pentax-lenses-explained.html

EDIT: And this:

http://mosphotos.com/PentaxLensesExplained.html
10-22-2009, 07:20 AM   #4
Pentaxian




Join Date: Sep 2007
Location: Bay Village, Ohio USA
Posts: 1,047
The short answer is that all those lenses should work on a K20D, although the M42 (screw-mount) lens will require a relatively inexpensive adapter (less than $30US).

SMC refers to "Super Multi-Coated", which was Pentax term for improved anti-flare coatings that were introduced in the seventies. This term was applied to both M42 screw-mount lenses and k-mount (bayonet) lenses.

M-series lenses were built to accompany the M-series cameras, introduced in the late seventies or early eighties. Inspired by the success of the Olympus OM-1, Pentax created the M-series cameras (ME, ME Super, MX, MG, MV) that were much smaller than previous cameras, such as the KX and K-1000. The "M" doesn't stand for manual focus, although they are, in fact, manual focus lenses. Back then, autofocus was just a gleam in the designers eyes, so there was no reason to differentiate between manual and auto-focus lenses. There was a variant, called the ME-F, that used a unique autofocus system. There was only one lens ever produced that autofocused with that camera.

Takumar is a name that Pentax used on their lenses for a long time. The simple Takumar name was used very early on, in the fifties. This was superceded by the Auto-Takumars, then the Super-Takumars and finally, the SMC-Takumars. In the early days of the bayonet era, the name Takumar was revived and placed on inexpensive lenses, designed to compete with third-party lens makers, such as Vivitar and Soligor. The Takumar lenses of this era lacked the SMC coatings and were not as highly regarded, optically, as their more expensive cousins in the Pentax lineup.

Please note that all these manual focus lenses must be used in stop-down metering mode. The K20D lacks the mechanical linkage to know the aperture setting of the MF lenses.

Any autofocus lens should work on a K20D with no problems.

10-22-2009, 09:52 AM   #5
Senior Member
chedoy's Avatar

Join Date: Dec 2006
Location: Chicago, IL
Posts: 143
QuoteOriginally posted by mattmiles Quote
Would these lenses fit a K20D and could you tell me if they are any good and worth purchasing? I am looking for a wide angle/fish eye lens for landscape photography but as i am just learning don't want to spend a great deal (plus i can't afford to spend much)

The first three are manual everything, I would guess that the DA 18:55 will do better than the other two you mentioned, except for being able to do 80 mm. If you already have the 18-55mm, there are some cheap AF 70-150mm zooms. I had a (used) Pentax FA model that cost me 50 bucks from keh.com. Everyone says it sucks, but I thought it was OK for my needs at the time. I did replace it later.

It will be tough to get a wide lens (under 18 mm) for your K20D that is inexpensive. Inexpensive to me means skipping a couple of beer/pizza nights out. Maybe more than tough. Maybe impossible.

Last edited by chedoy; 10-22-2009 at 09:58 AM.
10-22-2009, 12:16 PM   #6
New Member




Join Date: Oct 2009
Posts: 22
Original Poster
Thanks for the reply. I was wondering if there was any difference in the wideness of the shot with the Kit II lens and the Pentax M 1:2.8 28mm.

I am new to photography and was curious as the Kitt II lenses is an 18-55mm and the Pentax M 1:2.8 is 28mm. What do the 28mm and the 18mm mean. Does this mean that the KitII lens produces a wide angle shot.

Sorry if this seems a real beginners questions but unless you ask sometimes you never find out and people explain it hear better than in books or other sites.

Thanks

Matt
10-22-2009, 12:56 PM   #7
Pentaxian
Marc Sabatella's Avatar

Join Date: Sep 2006
Location: Denver, CO
Photos: Gallery
Posts: 10,686
QuoteOriginally posted by mattmiles Quote
Thanks for the reply. I was wondering if there was any difference in the wideness of the shot with the Kit II lens and the Pentax M 1:2.8 28mm.
If you set the zoom ring of the kit lens to 28mm, it will take a shot exactly as wide at the M28/2.8 - all 28mm lenses will produce the same field of view on any given camera.

QuoteQuote:
I am new to photography and was curious as the Kitt II lenses is an 18-55mm and the Pentax M 1:2.8 is 28mm. What do the 28mm and the 18mm mean.
What they *really* mean has to do with the physics of how these things work, and that isn't really all that relevant, any more than knowing what it *means* to say the temperature outside is 45 degrees Fahrenheit (eg, what defines the number "45"). What matters, of course, is that you have some sort of basic idea of what 45 degrees *feels* like. so if someone tells you it is 45 degrees out, you have some idea of how to dress. Similarly, where the number 28 comes from isn't all that important; what matters is that you have some idea of what the view looks like when using a 28mm lens.

The zoom ring on your 18-55 is how you learn this. Zoom all the way to the 18mm side and look through the viewfinder. That's wide. Now zoom all the way to 55mm. That's a lot narrower view (slightly telephoto). If you try 28mm, you'll find a sort of middle-of-the-road view - neither "wide" nor "narriow" (the term "narrow isn't normally used in this context, which is a shame, because "telephoto" actually means something slightly different, but we use the term colloquially to mean "narrow").

QuoteQuote:
Does this mean that the KitII lens produces a wide angle shot.
When the zoom ring is at 18mm, sure. But not at 55mm. And 28mm is smack dab in the middle.

On film camera, the meaning of these numbers is entirely different - kind of like switching to the metric system, where 45 degrees means something very different than it does to those of us accustomed to Fahrenheit. In Fahrenheit, 45 is pretty cold; in Celsius, it's very hot. Similar, on a typical DSLR, 28mm is "middle of the road", but on a typical film camera, it's about as wide as 18mm is on digital. If you Google the term "crop factor", you find more than you ever wanted to know about that, but you really don't need to know any of that. All that matters is that on the camera *you* own, 28mm is not wide.
10-22-2009, 01:00 PM   #8
Pentaxian
Marc Sabatella's Avatar

Join Date: Sep 2006
Location: Denver, CO
Photos: Gallery
Posts: 10,686
BTW, the M28/2.8 is one of my favorite lenses. It takes pictures of the same width (field of view) that the 18-55 does when set to 28mm, so it's not different in that respect. But it does f/2.8 - meaning you can get faster shutter speeds when necessary - plus it is just enough sharper to be noticeable. And the manual focus ring is much nicer than that of the 18-55, so in situations where MF makes more sense (like in low light - the same sorts of situations where you might need f/2.8), it can be easier to use. Plus it's half the size and weight. Not that the 18-55 is big or heavy, but I usually carry a bunch of smaller lenses rather than a couple larger ones.

10-22-2009, 01:09 PM   #9
Senior Member
chedoy's Avatar

Join Date: Dec 2006
Location: Chicago, IL
Posts: 143
Since you are probably away from your camera, here's a graphic of 4 different focal lengths as seen on a Pentax camera. You can see that as the focal length gets smaller, like from 18 mm to 16 mm, more stuff appears in the image. Small focal length means wider. Big focal length means more zoom. Easy?

Like Marc say, you can run anywhere between 18mm and 200mm with your zoom two lenses.

If you were able to put these lenses on other cameras, the images might look wider or more zoomed in, depending on whether their sensor is the same size as a Pentax.
Attached Images
 
10-22-2009, 05:27 PM   #10
Loyal Site Supporter




Join Date: Jun 2009
Location: Tumbleweed, Arizona
Photos: Gallery | Albums
Posts: 5,107
Pentax offers a genuine "Mount Adapter K (35m m Screwmount to Bayonet)" for $30.95

PentaxWebstore Mount Adapter K(35m m Screwmount to Bayonet)

I have also read in another post that someone wrote that they buy a separate adapter for each of their M42 lenses so that they essentially become a K mount, without having to bother moving a single adapter among lenses. That may become a bit expensive depending on the number of M42 lenses you acquire. Note - that even with the adapter, the lens remains a manual lens.

Also, rather than thinking of focal length, you can think of angle of view or field of view, i.e., how many degrees across the horizon does the lens take in. Here is a table that provides the field of view for various focal length lenses.

http://www.bhphotovideo.com/images/Angles-02z.jpg

hope that helps ...
10-25-2009, 05:55 PM   #11
Veteran Member
Barnster's Avatar

Join Date: Jun 2009
Location: Mid North Coast,Australia
Photos: Gallery
Posts: 1,013
If you do get the adapter,make sure it is the genuine Pentax version and not the cheaper inferior version.Of memory from a previous posting,the cheaper versions get stuck on the body and are hard to take off.Just be aware!
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!
28-80mm, af, camera, lens, pentax, pentax help, photography, takumar
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Will this lens fit my kx? 4ngi3 Troubleshooting and Beginner Help 13 06-30-2010 11:33 AM
Oh no! I got a lens that won't fit! Ouroboros Troubleshooting and Beginner Help 15 03-23-2010 08:12 AM
Will this lens fit my kx ??????? spanky66d Troubleshooting and Beginner Help 7 02-18-2010 03:23 PM
Does the K10D/K20D focusing screen fit the K-7? pasipasi Pentax DSLR Discussion 1 08-01-2009 02:16 PM
will this lens cap fit? pentaxbling Pentax SLR Lens Discussion 4 07-19-2007 05:14 PM



All times are GMT -7. The time now is 11:13 PM. | See also: NikonForums.com, CanonForums.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