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Old Mar 5, 2010, 9:18 PM   #1
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Default What is the best wide angle lens at small apertures?

We all the time are talking about the best lens at wide open and we also talk incessantly about the bokeh delivered by a fast aperture lens but to get the most detail in a wide angle landscape you need more Depth of Field.

So the question is...What lens gives the best results with a modern DSLR using the smallest aperture available for that lens? Ansel Addams was a member of the F64 club whose members were interested in getting the most detail from close up to far away in each and every photo they took. I know that there is a price in IQ from using a small aperture with the small sensor of the DSLR but which lens out there in the 15mm - 50mm range has the smallest aperture available and gives the best IQ?
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Old Mar 6, 2010, 1:05 AM   #2
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This isn't my area of expertise, but I can say that my 12-24 isn't that sharp at really small apertures - it's best from f4-f11.

My first thought would be one of the wide-angle macro lenses, since they are always designed for sharpness when stopped down. Maybe the DA 35 mm macro? It goes to f22, which is respectable.
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Old Mar 6, 2010, 8:18 AM   #3
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This isn't my area of expertise, but I can say that my 12-24 isn't that sharp at really small apertures - it's best from f4-f11.

My first thought would be one of the wide-angle macro lenses, since they are always designed for sharpness when stopped down. Maybe the DA 35 mm macro? It goes to f22, which is respectable.
That is the problem I'm running into in my quest. Not many go beyond f/11 or so in their photographs as the lenses do not seem to perform very well at f/16 and above. May be a problem with the sensors or just the newer lenses are aimed at that lower f/stops because of auto metering and focus that perform better at those settings.
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Old Mar 9, 2010, 3:12 PM   #4
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Hi Dawg... the problem with a lot of lenses is that one runs into diffraction problems after f/11 or f/16. This is why a lot of times you reach a point of diminishing returns in terms of sharpness after stopping down past a certain point. Dunno if you care, but here's an interesting piece on the subject:

http://www.luminous-landscape.com/tu...fraction.shtml

I suspect the Pentax DA 35mm f/2.8 macro Limited might be the lens you looking for in that range.

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Old Mar 9, 2010, 7:01 PM   #5
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Hi Dawg... the problem with a lot of lenses is that one runs into diffraction problems after f/11 or f/16. This is why a lot of times you reach a point of diminishing returns in terms of sharpness after stopping down past a certain point.
Hi Dawg,

Biro's right about the diffraction. f64 might have some relevance to 4x5 and larger view cameras, but doesn't really play well with smaller formats. The physically smaller lenses have correspondingly smaller diameter apertures, and diffraction shows its ugly head at larger f-stop values, so you rarely see anything smaller than f22. If you take a look at most P&S cameras, they stop at f11 (if they even get there) because their even smaller diameter apertures start showing the effects of diffraction even sooner.

Scott
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Old Mar 14, 2010, 7:42 PM   #6
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Quote:
Originally Posted by Biro View Post
Hi Dawg... the problem with a lot of lenses is that one runs into diffraction problems after f/11 or f/16. This is why a lot of times you reach a point of diminishing returns in terms of sharpness after stopping down past a certain point. Dunno if you care, but here's an interesting piece on the subject:

http://www.luminous-landscape.com/tu...fraction.shtml

I suspect the Pentax DA 35mm f/2.8 macro Limited might be the lens you looking for in that range.
Thanks Biro but the 35mm is really not as wide angle as I want.
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Old Mar 14, 2010, 7:43 PM   #7
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Hi Dawg,

Biro's right about the diffraction. f64 might have some relevance to 4x5 and larger view cameras, but doesn't really play well with smaller formats. The physically smaller lenses have correspondingly smaller diameter apertures, and diffraction shows its ugly head at larger f-stop values, so you rarely see anything smaller than f22. If you take a look at most P&S cameras, they stop at f11 (if they even get there) because their even smaller diameter apertures start showing the effects of diffraction even sooner.

Scott
Thanks Scott. All this I've read before but needed reinforcement from my friends...still and all...the question remains...which wide angle lens does the best job?
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Old Mar 14, 2010, 8:34 PM   #8
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You really don't need to stop down a wider lens that much, because your hyperfocal distance is going to be relatively close to the camera anyway.

For example, using a camera with a typical APS-C size sensor (K7, etc.), if you shot with a 20mm lens at f/8, the hyperfocal distance is only around 8.3 feet. So, if you focused at around 9 feet away, everything from less than 5 feet from to infinity should be acceptably sharp at most viewing/print sizes.

If you went to f/11 with a 20mm lens, the hyperfocal distance drops down to around six feet. So, you could focus at around 6 feet away and have everything from about 3 feet to infinity acceptably sharp.

http://www.dofmaster.com/dofjs.html
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Old Mar 14, 2010, 9:39 PM   #9
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My Mamiya medium format's 65 mm wide angle goes from F 2.8 to F 32 and the 180 mm telephoto Mamiya MF lens in my kit, goes to F 45.

I think it maybe the larger the camera format the greater the aperture #, although my Pentax DA 50 mm Macro F 2.8 also goes to F 32.
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Old Mar 15, 2010, 11:12 AM   #10
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The larger the sensor or film size, the shallower the depth of field for a given subject framing and aperture. The smaller the sensor or film size, the greater the depth of field for a given subject framing and aperture.

That's why you have a lot of depth of field shooting with a point and shoot model versus a dSLR. Because of the smaller sensor size, you can use a shorter "actual" focal length lens for the same framing, resulting in a lot more depth of field with the smaller sensor for a given aperture and framing. The same thing applies comparing medium format to 35mm or APS-C size sensors (i.e, you don't need to stop down as much for the same depth of field for a given subject framing when shooting with cameras using smaller sensors or film sizes, because a shorter actual focal length lens can be used for the same subject framing as you use smaller sensors or film sizes).

A smaller sensor is also one reason why most point and shoot models don't let you stop down the aperture much over f/8 (and some don't even stop down that far).

The smaller the sensor size, the sooner you'll run into diffraction issues (starting to get softer photos past a certain aperture, regardless of lens quality). See the calculator on this page:

http://www.cambridgeincolour.com/tut...hotography.htm

Now, some lenses that work with dSLR models can go to f/32 or even f/45. But, as a general rule, once you start getting past about f/11 with a typical APS-C sensor), you're going to start getting softer images than you would if you stuck with apertures around 2 or 3 stops from wide open, no matter what lens you use (as diffraction issues set in because of the sensor's size, regardless of optics design)

It may not make much difference, depending on what you're shooting (i.e., the need for more depth of field can outweigh the softness you'll start to get from diffraction issues, as compared to how much a lens can resolve at more optimum apertures for a given sensor size). But, with a wider lens on an APS-C size sensor, you have lots of depth of field by the time you stop down to around f/11 or so anyway. So, there is rarely any need to stop down much further unless you're shooting macros.
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