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04-16-2011, 12:00 PM   #1
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wide angle lenses

Does anyone know of a good wide angle lens for the K20D?

04-16-2011, 12:11 PM   #2
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Autofocus or manual focus? Budget?

DA15Ltd is (currently) the big favorite on this forum if it comes to a modern lens. From the current Pentax lineup:
DA14, DA15Ltd, DA21Ltd, DA12-24.

Sigma also has some wide stuff.
04-16-2011, 12:13 PM   #3
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DA 14

DA 15

DA 21

DA 10-17

DA 12-24

Sigma 10-20
04-16-2011, 01:42 PM   #4
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I'll also add in the Sigma 8-16.

However, all of this comes back to what you want to spend, along with what do you want to do with the lens - landscapes, architecture, interiors, exteriors, ..... etc. The wider you go, the more distortion you gain, so within the real of wide angles, begs the question of how wide do you want to go.

Also, the focal lengths tend to not convey the idea of how wide of a view you are getting. So here is a conversion into angle of view in degrees (horizontal):
8mm = 112 degrees
10mm = 100 degrees
12mm = 90 degrees
14mm = 81 degrees
16mm = 73 degrees
18mm = 67 degrees
20mm = 61 degrees
22mm = 57 degrees
24mm = 53 degrees
These values are from the Angular field of view Calculator (using a crop factor of 1.5) at


04-17-2011, 03:37 AM   #5
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it will mostly be for landscapes, I dont really have a budget as I didnt realise that they would be so expensive :s
04-17-2011, 03:48 AM   #6
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Kit lens? Or DA16-45 (only available second hand I think)? And the second hand market with AF and manual focus lenses; although extreme wide angles (below 20mm) from the film era might be rare.

Overview of most lenses available for Pentax:
Pentax Reviews - Pentax Lens Reviews & Pentax Lens Database
Third-Party Lenses for Pentax - Pentax Third-Party Lens Review Database

Good luck with the shopping; note that you need an adaptor for M42 lenses and be aware of lenses that possibly can have the Ricoh pin as they might get stuck on the camera.

Last edited by sterretje; 04-17-2011 at 03:55 AM.
04-17-2011, 08:07 AM   #7
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The DA 21 would be a good place to start. What are you using now.
04-17-2011, 12:52 PM   #8
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As with most items, the more extreme you get, usually the higher the cost. Wide angle lenses are the same. You are going out to an extreme, where the light needs to be bent or redirected from the edges on to the camera's sensor. That takes glass and engineering to accomplish. Also, in doing so you create distortion, that takes more glass and engineering to compensate for.

The kit lens is really very good at 18-55mm. At the wide end you are at 67 degrees. If you have the kit lens, I would just start there and go out and try experimenting (its not like the "film" is not free). You can also "stitch" - see below for an explanation.
The 16-45 lens is better at 16mm and you gain another 6 degrees of width. It is also reasonably affordable at $200-$250 (given what the other lenses go for).

The other lenses climb in price as they get wider and the distortion is controlled to the extent possible.

Another alternative is stitching. Essentially taking adjacent images (with some overlap ~20-25%), and then using software to "stitch" them together. Its really pretty easy. Microsoft's ICE software is free and very easy to use - it also does a pretty good job.

http://research.microsoft.com/en-us/um/redmond/groups/ivm/ICE/

... hope that helps ....




Last edited by interested_observer; 04-17-2011 at 12:57 PM.
04-17-2011, 07:21 PM   #9
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Most published landscape photos are shot within a focal range equivalent to 18-55mm on your K20D, so your kit lens is a good place to start. Stop the aperture down to f/8 and you'll be fine. If you want to stitch wider panos, shoot with the lens around 28mm to minimize distortion. Yes, the DA16-45 is slightly better optically, and costs hundreds of bucks. Buy one. Make the officers and shareholders of PenHoya happy.

As mentioned, wide lenses are costly, and ultra-wide lenses are costlier, and autofocus wide and ultrawide prices can make your eyes bleed. Many people associate LANDSCAPE with ULTRAWIDE and mortgage their futures for superduper ultrawides. But wider lenses diminish distance -- they're best for showing a close subject within its context, or for revealing small enclosed spaces, not for capturing The Great Outdoors.

Really, start with your kit lens. Then ask yourself what you want to do that you can't do with what you already have. That will inform your future lens choices. Enjoy!
04-17-2011, 07:33 PM   #10
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For landscapes get the 16-45. You don't need an ultrawide to take a good landscape (in fact I'd bet you will find yourself taking quite a few in the 20-30mm range).
04-17-2011, 11:36 PM   #11
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I would suggest going back to the main page, scrolling down to the lens clubs, click there and then find the kit lens club. Take a look at those images - they are wonderful. One nice thing about Pentax, is that the kit lens is one of the better ones around. You are able to do just about anything with it. I would experiment around with it for at least a few months, before deciding to spend any money. The kit lens and a stitcher can work wonders..... also helps the check book and damage to the credit card.

04-18-2011, 12:11 AM   #12
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I Sigma 10-20 and extremely happy look sigma 1020 club sectionThis lense very good for landscape
04-18-2011, 12:16 AM   #13
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If you don't have a budget, and you find the new range of prime lenses expensive, then you are probably best going with flexibility. As others have noted, the Pentax kit (short zoom) lens, the 18-55, can be had quite cheaply second-hand and is a remarkably good performer for the money.

Even second-hand good primes at the wider end of the range, such as the FA20 are hard to come by, and can be as expensive as some of the better new wide zooms (such as the Sigma 10-20). If you don't mind focussing manually, then perhaps an older K-mount like the 24 or 28 may be more in your price range. The 'A' versions are more expensive than the earlier variants, but will communicate aperture information to your DSLR, making your task that little bit easier.

However, given that you're interested in landscapes, having to focus and set aperture manually probably isn't so much of a chore as if you were intent on moving subjects. It's also a good way to learn more of the craft side of photography.

First things first, though. Perhaps you should work out how much you're willing to spend, and then start weighing up the balance between the various factors at play here.
04-18-2011, 12:47 AM   #14
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As has been mentioned, for landscapes, it may be that you won't actually need an expensive wide-angle lens. Do check this out with your kit lens, because if you find yourself around the 30mm mark a lot of the time, then there is a very cheap solution (other than just staying with the kit lens, of course): get yourself a decent manual-focus 28mm lens.

Don't be deterred by the fact that it's mf, because for landscapes you're likely to be stopping down to f8/f11, and at these apertures you're better off with hyperfocal focusing: make use of the DOF markings on the lens barrel to set the lens focus distance so that infinity is within the DOF. Note that you'll need to use the marks for an aperture 2 stops wider than you've set - so, for f8, use the marks for f4. This is because the lens markings will assume a larger sensor size than the K20D's.

Recommended lens would be the Vivitar 28mm f2.8, made by Komine (identified by a serial number 28........). This should be readily available cheaply, and, especially when stopped down, will be a step up in sharpness compared to the kit lens.
04-24-2011, 05:33 AM   #15
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Thanks everyone for all the advice
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