[axl]

I realize "it works" I just mean to say that a wide angle film lens is no longer so wide on a dslr as in it doesn't work to take such a wide angle feild of view photograph. So if you really want a functional wide angle lens to use on your dslr you need a new one designed for apsr.

No yo don't!
15mm designed for film (ie K or A15/3.5) will see exactly the same as DA15/4 when both are used on DSLR.

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Last edited by axl; 02-18-2010 at 04:17 PM.

[axl]

Lenses that wide weren't cheap for 35mm format either. APS-C versus 35mm barely enters into it. But my question would be, what experience do you have that convinces you that you want something in the 10-12mm range on APS-C? Were you accustomed to using 15-18mm lenses on film? What I'm getting at is, how do you know 14, 15, or even 16mm wouldn't be enough for your purposes?

Fair point, but if you can have 10-20 covered, why would you want 16 - 45 only

[GeneV]

.

Yes, I think a contrasty, sharp zoom that gets out to 16mm would be 1) wide enough on aps-c for most WA applications, and 2) great if it could be had for $250 or less used.

Too bad something like that doesn't exist.

Oh, wait!


Stopped down, the DA 16-45 is a very good WA tool and is basically a great value any way you add it up.


.

I thought for sure we were about to be treated to another of your excellent DA15 shots.

[GeneV]

marc raises a good point.

I can't obviously speak for the OP, but form my own experience, when I shot film, the widest I had was a 24mm and I was frustrated that it was not wide enough. That is equivelent in todays world to a 16mm on ASP-C.

when I got my *istD, I took the FA-J 18-35 that came with it and used that on my PZ-1 for wide shots.

I finally was approaching what I wanted, so for the complete move to digital I went for a sigma 10-20. Still shoot 60% of all shots with that lens at 10mm. Now I'm looking at an 8mm fisheye

I've gone through some of the same evolution. Putting the DA15 on my ZX-L has given me 10mm envy.

[panoguy]

Now I'm looking at an 8mm fisheye

Check out the Samyang 8mm (Polar, Vivitar, Bower, etc.). Not your typical, mushy "circular fisheye" - it has a "different" kind of field distortion - which makes it ideal on an APS-C sensor camera.
(edit: I see you've already looked into this...)

Ohmygosh! I think we just hit on a "cheap" ($300) and very wide-angle lens for Pentax!! Gasp! (But prepare to manual focus in a fishbowl...)
I like the Pentax 10-17 fisheye myself - not too pricey, sharp as they come, and AF to boot!

[Pentaxor]

I realize "it works" I just mean to say that a wide angle film lens is no longer so wide on a dslr as in it doesn't work to take such a wide angle feild of view photograph. So if you really want a functional wide angle lens to use on your dslr you need a new one designed for apsr.

nope, that is a misconception. a 35mm film lens will have the same FOV as that of a 35mm digital lens whether on an APS-C dslr or full-frame slr. FOV is dependent on the camera's sensor size, not the lens' focal length. the camera does the cropping, not the lens. when they say that the lens is enhanced for APS-C camera, it means that the lens designed for the APS-C dslr are enhanced in a way that they would appear or look better when used on an APS-C dslr. it doesn't mean that it would make the FOV of a DA16-45 at 16mm retain or display a focal length value of 16mm on an APS-C dslr. it would still get cropped by a factor of 1.5 which is equivalent to approximately 24mm. that's why when you look at the specs of an APS-C lens, it mentions 35mm equivalent focal length of that particular lens.

here are some notes regarding about Pentax lenses and bodies.

1.> all old full-frame Pentax mount lens will work on an APS-C dslr. Pentax lenses with a different mounting would work with a proper adapter mount.

2.> all old full-frame Pentax lens will have the same FOV of that of an APS-C lens on an APS-C dslr.

3> not all DA or APS-C designed lenses will work nor work efficiently on a Pentax full-frame camera. exceptions are the DFA lenses and other Pentax lenses that are full-frame compatible. also known as dual-compatibility.

4.> some old Pentax full-frame lenses work much better than the APS-C designed lens. this is in terms of overall IQ. some notable parts are very low or non-existent distortion, resolution, and colours.

5.> FOV is dependent on camera sensor size.

[Pentaxor]

the real use of an ultrawide lens is for corner shots to corner shots without requiring panoramic shots or stitching.

such shots include indoors shots, tight corridors, stairs, etc... and outdoor which concerns close up close corner shots of buildings, cityscapes, streets, bridges, etc...


for subjects like landscapes and architectures with considerable and acceptable distance, a 16mm or 18mm would be enough.

at the end of the day, such wide lens acquisition would definitely depend on your working space around the subject.

[Just1MoreDave]

Thanks for all the info guys! Sounds like a wide angle lens is a difficult engineering feat! One other thing that occured to me is that mainstream APS-C DSLRs have only been around for a few years. And the film lenses made most obsolete by DSLRs are wide angles lenses. So DSLR wide angles are high demmand (since old ones don't work) and low supply (since they have only been sold for a few years).

nope, that is a misconception. a 35mm film lens will have the same FOV as that of a 35mm digital lens whether on an APS-C dslr or full-frame slr. FOV is dependent on the camera's sensor size, not the lens' focal length. the camera does the cropping, not the lens. when they say that the lens is enhanced for APS-C camera, it means that the lens designed for the APS-C dslr are enhanced in a way that they would appear or look better when used on an APS-C dslr. it doesn't mean that it would make the FOV of a DA16-45 at 16mm retain or display a focal length value of 16mm on an APS-C dslr. it would still get cropped by a factor of 1.5 which is equivalent to approximately 24mm. that's why when you look at the specs of an APS-C lens, it mentions 35mm equivalent focal length of that particular lens....

All true, but you're missing one thing. Film responded well no matter what angle light hit it at. Sensors do not, and WA lenses intended for sensors straighten the light rays out before they strike the sensor. They have less vignetting as a result. An old lens might work in the sense of getting a photo, might gain something from only using the center part of the lens, then lose that advantage because of a factor its designers never considered.

[8540tomg]

Quality lenses are hard to make and can take up to 6 week to make one lens. Specialyl when you take in mind the design, abbriviations, clarity, fringing, distortions reflections, flares and on............

Check this video from the discovery channel to get an idea on how lenses are made.

[YT]http://www.youtube.com/watch?v=X7_wL0ZZi6k[/YT]

Thanks for posting this. I had not seen it before. Considering the time, effort, technology, skill and materials it takes to produce a lens they almost seem like a bargain.

Tom G

[Rondec]

I have to say, that when I shot film, I never shot wider than 24 mm -- that is roughly 16mm equivalent on APS-C. I think you have to be a little careful when you get really wide angle lenses -- there some pretty amazing distortion on the Sigma 10-20 at the wide end. you can get a lot into the photo, but nothing looks quite right. Distortion seems much better controlled on the DA 12-24, but then again, it isn't as wide either.

[ozlizard]

The Sigma 10-20 IS cheap! A lens of that quality for $5-600 is great valur IMHO. Even cheaper second hand. What sort of crappy lens are you going to get for under $200? You only get what you pay for!

[Marc Sabatella]

If you want $200 worth of wide angle, you can always get one of the "wide angle adapter" filters to attach to the front of another lens.

[Steve Beswick]

Another option that I'm surprised nobody has mentioned is the going-to-hit-the-market-any-day-now samyang 14mm f2.8. It works out to be roughly equivalent to 21mm on film, and it should be somewhere in the neighborhood of $250-$350. Sure, it's manual focus, but is that really a problem with a 14mm lens?

[Pentaxor]

Another option that I'm surprised nobody has mentioned is the going-to-hit-the-market-any-day-now samyang 14mm f2.8. It works out to be roughly equivalent to 21mm on film, and it should be somewhere in the neighborhood of $250-$350. Sure, it's manual focus, but is that really a problem with a 14mm lens?

why would it be equivalent to a 21mm on a full-frame film? you don't meant APS-C dslr, do you?

[ProfHankD]

If you want a cheap lens that is wide on an APS-C DSLR, you've got a serious problem because the crop factor makes you want a very short focal length and avoiding the mirror forces the back of the lens to be too far from the sensor (more than ~40mm). Thus, we're talking retrofocus lenses, and it wouldn't be far off to think of one such lens as a simple wide angle lens packaged with a second lens to reproject the image behind it. There are about twice as many elements as in a longer focal length lens. Zooms complicate the design further, and the fact that people love zooms has made tele-biased zooms the dominant market.

Options for that wide-angle look on APS-C:

(1) Redefine $500 to be cheap and buy the Sigma 10-20. I use mine at 10mm more than 90% of the time. It's great when stopped down to f/8, but very soft wide open. There are a few fixed focal length or zoom competitors for this lens, but I have yet to find one as cheap that equals it. Incidentally, part of why this lens works is that it doesn't have to cover full frame, just APS-C.

(2) Get used to cropped wideness. For example, my M42 35mm f/3.5 SMC Takumar definitely has the depth of focus and colors of a classic moderate wide landscape lens. Even though an APS-C sensor doesn't capture a wide angle of view using this 35mm lens, it still captures landscapes just as beautifully and with the same "look." Of course, it is problematic when you can't step back any further to fit things in....

(3) Hunt down an old rectilinear lens in the 17mm-25mm range. There are plenty; I have a Spiratone 18mm, Vivitar 20mm, and Tamron 24mm. Catch is, they're not great IQ and pricing is going nuts: often well over $100, and don't even think about the Flektogons on a budget. Generally, the design and construction is quite good, but the coatings aren't great, and with lots of elements that leads to low contrast and more potential for flare. Often, there's CA too (which the sensor and microlens array make worse than it was for film -- they don't handle light arriving at angles well). The good news is that most of those IQ issues can be helped in postprocessing, so final IQ might surpass that of a modern kit zoom.

(4) Use a distorting wide angle lens and digitally correct. Lenses with a little barrel distortion are easier to make (e.g., Panasonic's 14-140mm and 20mm) and perhaps we'll soon see lenses for other than 4/3 mount doing this deliberately to improve cost, size, and IQ. For now, cheap fisheye and supposedly non-fisheye wide-angle auxiliary lenses that screw on your lens like a filter often produce surprisingly decent image quality except for distortion and CA, which can be corrected in postprocessing. Just be careful about putting heavy auxiliary lenses on plastic-body kit lenses. There are also various prime fisheye lenses, with my personal favorite being the old Accura 12mm f/8 I got for about $65.

Personally, I favor option (1)... but (4) is your cheapest answer for getting really wide on APS-C, and it is viable. Actually, I do all four.