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02-17-2009, 10:04 PM   #1
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wide angle question

hi, i'm thinking about buying a wide angle lens but what i'm looking for is a combination of the widest picture possible and the shortest/least bulky length. i would like wider than 24 or 28mm, ideally 15 or 16 but is this possible?

also, i don't really want a zoom lens but it seems like the non-zoom lenses are more expensive in this area. just looking for something small i can leave on my camera.

extreme newbie here, thanks!

02-18-2009, 01:31 AM   #2
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QuoteOriginally posted by murphyinc Quote
hi, i'm thinking about buying a wide angle lens but what i'm looking for is a combination of the widest picture possible and the shortest/least bulky length. i would like wider than 24 or 28mm, ideally 15 or 16 but is this possible?
Sounds exactly like the DA15 Limited that has been announced and should be out within the next next or so - it's comparable size-wise to the other DA limiteds (which is to say, very small). Of course, no one knows what the price will be yet.
02-18-2009, 01:56 AM   #3
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but the DA lenses don't work on regular camera bodies, right?
i should add that i was previously looking for one lens that could go on both without sacrificing too much on the digital side, the 1.5X (i forget what the name of the measurement is). i'm not sure that's possible either, though.

anything, say, half the price? or am i basically investing in a lens that might cost more than both cameras combined?
(price based on the DA21)

Last edited by murphyinc; 02-18-2009 at 01:58 AM. Reason: $600!
02-18-2009, 02:11 AM   #4
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from existing AF lenses one that would match your criteria is FA20/2.8, how expensive it is and IF you would be able to get hold of one at all I don't know. There is Sigma 20/1.8 but considerably bigger and again I'm not sure about availability and price. Last option is DA14/2.8 good lens apparently, though bit bigger than FA20 but I wouldn't say it's bigger then Sigma 20. If you are looking for anything smaller, your only option at the moment is to wait for DA15ltd, or settle down with 21ltd.
BR

02-18-2009, 10:22 AM   #5
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QuoteOriginally posted by murphyinc Quote
but the DA lenses don't work on regular camera bodies, right?
By "regular" I assume you mean 35mm film. The DA lenses work in the sense of you can take a picture with them, but the image might not fill the whole frame (some are better than others in this respect). You get dark borders around your image. That's called "vignetting".

QuoteQuote:
i should add that i was previously looking for one lens that could go on both without sacrificing too much on the digital side, the 1.5X (i forget what the name of the measurement is). i'm not sure that's possible either, though.
"Crop factor" is the term you are looking for. There is no lens that is immune from this effect. A piece of 35mm film is bigger than the sensor in a Pentax DSLR, so no matter what lens you attach, you'll get a different field of view between film and digital. No way around that. So yu have to decide if you want something around 15mm - which is "incredibly" wide for film, "very" wide for digital - or something around 22mm, which is "very" wide for film but only "somewhat" wide for digital.

QuoteQuote:
anything, say, half the price? or am i basically investing in a lens that might cost more than both cameras combined?
(price based on the DA21)
At $400-ish, The DA21 is about as cheap a modern wide angle lens as you are likely to find, but it's not all that wide on digital - nowhere near what you're talking about. And of course, it vignettes on film. Some older film lenses can be found used that are wider and will work with both film and digital, but they aren't generally cheaper than the DA21. I'm guessing the DA15 will be comparable in price to the DA21, BTW - it seems all the DA Limiteds except the 40 are in that same general price area.
02-18-2009, 02:07 PM   #6
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You need to remember that on APS C sensors, "Normal" is about 28mm. On 35mm a "Normal" lens is 50mm (really about 43mm).
A 24mm film lens is just barely wide on digital.
02-18-2009, 02:35 PM   #7
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I will beat the fisheye drum.

Many of us have gone to various fisheye lenses in the 15-16mm range as a wide-angle solution. The cheapest option new is the Zenitar 16/2.8 in k-mount (about $200 USD through various gray-market online merchants). The Zenitar is pretty compact (about the same size as many 50mm lenses) and the optics are quite adequate. The distortion is manageable and the lens is still usable as a fisheye on 35mm film. See the reviews in the third party lens database.

Here is a photo (lifted from the Web) of the Zen mounted on a *istD to give an idea of size:



Steve

Last edited by stevebrot; 02-18-2009 at 02:43 PM.
02-19-2009, 10:05 PM   #8
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calicojack -- you're talking about specifically film lenses, right? for instance, a 28mm *digital* lens on a digital camera is still 28mm...

...or do you mean a 28mm *digital* lens on digital shows the *same* picture as a 50mm lens on slr...

thanks all, this narrows things down! stevebrot, that's exactly what i was looking for, but now, more questions --

if a lens doesn't actually say it's fisheye, should i assume it's not?
and if it's a super-wide digital lens, does the camera actually "fix" the image automatically, or just jpg (versus raw), or none of the above?

i was looking at the pentax gallery for 12-24mm because of these questions and i don't see any distortion...

02-19-2009, 10:45 PM   #9
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QuoteOriginally posted by murphyinc Quote
calicojack -- you're talking about specifically film lenses, right? for instance, a 28mm *digital* lens on a digital camera is still 28mm...

...or do you mean a 28mm *digital* lens on digital shows the *same* picture as a 50mm lens on slr...

thanks all, this narrows things down! stevebrot, that's exactly what i was looking for, but now, more questions --

if a lens doesn't actually say it's fisheye, should i assume it's not?
and if it's a super-wide digital lens, does the camera actually "fix" the image automatically, or just jpg (versus raw), or none of the above?

i was looking at the pentax gallery for 12-24mm because of these questions and i don't see any distortion...
Nothing gets "fixed" automatically. Here is the skinny on ultra-wides:
  • You need a short focal length for a wide field of view (duh...)
  • There are certain kinds of distortion associated with short focal lengths. A rectilinear lens (such as the Pentax 12-24) will attempt correction of that distortion. (See this helpful article on distortion on PT Lens Website. Click the menu item for "Distortion".)
  • It is difficult to design a true rectilinear lens at focal lengths less than 20mm for the 35mm or APS-C image circle.
  • Distortion may be corrected using special software such as PT Lens (I am not affiliated with the software author, I just think it is a reasonably good product.)
  • Diagonal fisheye lenses also have a wide field of view, but are designed to project the image to a particular mathematical model to allow 180 degrees or more field of view. Straight lines become curves, but this is not the same as barrel distortion.
  • Fisheye lenses designed for 35mm film (such as the Zenitar) have a less "fishy" rendering with the APS-C sensor that is similar to a moderate barrel distortion. This moderate "fishiness" may be minimized by careful composition or completely corrected using software.
  • Fisheye lenses are almost always labeled as such
  • Rectilinear ultra-wide lenses almost always have some degree of barrel or moustache distortion

Here are three pictures taken with the Zen. None have been corrected. All were taken with the K10D within a few hours of each other:

This one is fairly fishy



This one is less so



And this one is hardly fishy at all



Steve

Last edited by stevebrot; 02-19-2009 at 11:03 PM.
02-26-2009, 10:31 AM   #10
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one more question!

one more question -- which is a better deal?

there's one lens with an A next to the apertures, which i'm assuming is automatic? so this will autofocus? but the f-stop is smaller than the second lens, which is just manual (and cheaper!).

i do want to learn, so i don't mind another manual lens, and i've used the manual settings on a *DL, i'd just like to have the focus option, unless that A means something else.
02-26-2009, 11:25 AM   #11
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QuoteOriginally posted by murphyinc Quote
there's one lens with an A next to the apertures, which i'm assuming is automatic? so this will autofocus? but the f-stop is smaller than the second lens, which is just manual (and cheaper!).
That lens won't autofocus, but if you put the aperture ring in the "A" position the camera will be able to meter the picture automatically. That means you'll be able to use all of the camera's metering modes (Auto, Av, Tv, etc) without having to press the "green button" to pre-set the exposure before taking the shot. But you WILL still have to focus manually before you take the shot.
02-26-2009, 11:38 AM   #12
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The A probably stands for Auto, but Auto has been used for every other lens feature so just forget that it stands for anything. The camera can control the lens aperture when the lens has an A setting. It doesn't sound like much, though it affects many features on the camera.

With an A lens, you can use all the camera modes, with a basic K-mount, you're stuck in M. The A lenses allow multisegment metering and multiple AF points, basic K-mounts use center weighted metering and the center focus point. Flashes work better with A lenses. The thumbwheels adjust aperture. Metering works in real time, no pressing a button to get a reading. The aperture reading is visible in the viewfinder and recorded in EXIF data. It's not unusual for an A lens to sell for twice as much as a basic K-mount, even if the A lens is optically worse.

Autofocus lenses all have the same functions as A lenses do. They also tell the camera the focal length, a big convenience if you have SR.
02-27-2009, 09:26 AM   #13
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To put it another way, with the aperture ring on "A", the lens will behave just like a DA lens as far as metering goes (still not AF unless the lnes happens to also be an AF lens). With the aperture ring, not on "A", it will act like an "M" or other fully manual K-mount lens.

As for maximum aperture, that's often not all that important a consideration when choosing a wide angle lens - these are not typically lenses one would use for their low light handholdability or for the ability to create really shallow DOF.
02-27-2009, 09:42 AM   #14
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FA 20-35 f4

I happen to have one of these up in the marketplace right now, sounds like it could fit the bill for you.

It's small (same size and weight as kit lens). It physically extends a few millimeters over the zoom range. It has a constant aperture and the optics are outstanding. Check the reviews on this site or elsewhere online, during its production run it had been called the sharpest zoom in its range from any manufacturer.

And it's full-frame format, i.e. works on both digital and film bodies.

It's been discontinued over the last couple years but sold for ~ $500 new. I priced it the same as a used DA 21mm, but it's a little more versatile.
02-28-2009, 12:23 PM   #15
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QuoteQuote:
The A probably stands for Auto, but Auto has been used for every other lens feature so just forget that it stands for anything. The camera can control the lens aperture when the lens has an A setting. It doesn't sound like much, though it affects many features on the camera.
QuoteQuote:
As for maximum aperture, that's often not all that important a consideration when choosing a wide angle lens - these are not typically lenses one would use for their low light handholdability or for the ability to create really shallow DOF.
ok, that helps a lot!
sorry to the last post, i just bought a 19mm vivitar, f3.8 with the A on the side.

can't wait for it to get here!
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