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02-24-2010, 11:31 AM   #1
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Purpose of a 28mm 2.8?

I've been evaluating my kit lately and started to doubt me owning a 28mm 2.8. Well, as of now two actually but one of them I'll sell anyways.
I'm struggling to find a good use for it, since it's range lies in the 18-55 already. It is a bit faster, sure, but somehow either of the two lenses only really start to get sharp around f/6 or so.
What do you guys do with a 28mm f/2.8 on your digital bodies?

02-24-2010, 11:41 AM   #2
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A good 28/2.8 is sharper wide open than the kit lens is at f/8, and is considerably smaller/lighter. I love my Vivitar 28, and I use it a lot as a walkaround prime.

Which 28/2.8 are you using?
02-24-2010, 11:52 AM   #3
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I've used a Panagor E-PMC Macro (never seen another one of those anywhere) quite extensively and I now also have a Panagor PMC (I've seen a few of these in Nikon F-mount. Haven't really had a chance to compare either, I might print some test charts soon.
02-24-2010, 11:55 AM   #4
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if you are critical about overall IQ, you will easily notice that a prime 28 would beat the kitlens. and yes, some people find that the extra speed useful in lowlight and rendering a shallow DOF.

I had compared my kitlens with my prime 28, and saw how really good the prime is.

02-24-2010, 11:58 AM   #5
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QuoteOriginally posted by Lauke_101 Quote
I've used a Panagor E-PMC Macro (never seen another one of those anywhere) quite extensively and I now also have a Panagor PMC (I've seen a few of these in Nikon F-mount. Haven't really had a chance to compare either, I might print some test charts soon.
I see. I haven't had any experience with any Panagor lenses. there are a lot of them for sale but I never bought one since I'm highly doubtful of their IQ.

you might want to try out the Pentax 28mm primes and do some comparisons with the Panagor primes?
02-24-2010, 12:45 PM   #6
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I have the Sigma 28mm f/1.8 and it is my favorite lens. I use it all the time.
02-24-2010, 12:46 PM   #7
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And then there is also the possibility of using it on film.

02-24-2010, 02:07 PM   #8
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QuoteOriginally posted by Lauke_101 Quote
I've been evaluating my kit lately and started to doubt me owning a 28mm 2.8. Well, as of now two actually but one of them I'll sell anyways.
I'm struggling to find a good use for it, since it's range lies in the 18-55 already. It is a bit faster, sure, but somehow either of the two lenses only really start to get sharp around f/6 or so.
What do you guys do with a 28mm f/2.8 on your digital bodies?
Here is a comparison between the kit lens at 28mm and my Pentax K 28mm F3.5.
Aperture is F4. Left: Kit lens Right: SMC K 28mm F3.5.

Kind regards
.lars
Attached Images
 
02-24-2010, 02:11 PM   #9
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I have the Pentax M 28mm f2.8, and find its a great walk around lens for me. The "normal" focal length (on APS-C) is perfect, and the small size makes is less obtrusive for some people. The only thing I wish is that it were PK/A mount because I hate having to do stop down metering, and when you are walking between shadows of buildings in the CBD, the lighting changes so dramatically so often!

I have used it wide open quite often, always with good results.
02-24-2010, 03:15 PM   #10
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Lars, you posted that before, but now I'm wondering, is that a 100% crop? Because that's *much* worse than anything I've seen even from the kit lens (although as I recall, yours ithe version I).

Basically, the reasons to use a 28 instead of the kit lens (version II) are either:

- you need the extra stop or so of speed
- you need the extra sharpness you get up to about f/8, after which the differences are negligible
- you're just a prime kind of person
02-24-2010, 06:09 PM   #11
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QuoteOriginally posted by Marc Sabatella Quote
Lars, you posted that before, but now I'm wondering, is that a 100% crop? Because that's *much* worse than anything I've seen even from the kit lens (although as I recall, yours ithe version I).

Basically, the reasons to use a 28 instead of the kit lens (version II) are either:

- you need the extra stop or so of speed
- you need the extra sharpness you get up to about f/8, after which the differences are negligible
- you're just a prime kind of person
Marc, I have the 18-55 WR and basing from the shot comparisons that I made against it and the K28/3.5, FA35, and FA50/1.7, the resolution of the WR kitlens seems to suffer more with the 18-55 as you shoot longer at midrange to infinity, irregardless if you stop down or not. I did shoot at 3 varying stops from f4, f5.6 and f8 at 28mm, 35mm, and 50mm.

the 18-55 did very with up-close shots at those focal length against the 3 other lenses, although it appeared that the 3 lenses have quite some advantage in resolution. the advantage becomes more apparent as you move further away. stopping down doesn't improve it sharpness. and the image becomes more blurry. I also tried an image text test.

I also noticed such weakness when I compared the 18-55 against the 12-24 set at 18mm and 24mm with apertures f4 to f8 respectively when I did some architectural shots last year. even at f8, the 18-55 is no better.
02-24-2010, 06:59 PM   #12
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Well, this was shot with an M28/3.5, not a 2.8. Still, it's sharper than the kit lens, lots smaller, and feels better, too!



By the way . . . thanks to deadwolfbones for this lens: I shot this the day after I received it from him in the mail. (Thanks, Ben!)
02-24-2010, 09:10 PM   #13
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I have two 28mm lenses (Tamron 28/2.5 and Vivitar 28/2.8 CF). Here are my thoughts:
  • My kit lens (v. I) at 28mm is a notch off either prime, but not by much
  • A 28/2.8 will provide narrower DOF and needs less light than the kit
  • The best use of 28mm on an APS-C dSLR is as a "short normal"
  • Some designs are very compact
  • Both my 28s are quite capable on my K10D, but really shine as a wide-angles on 35mm full-frame
I have the FA 35/2. As a result, I mostly use 28s as wide-angles with the film cameras.

Steve
02-24-2010, 09:45 PM   #14
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it makes a perfect video lens for me Im using a Nikkor AF 28/2.8 (yes, on my Pentax body)

the kit lens is at F4/4.5 at 28mm right?
02-24-2010, 10:00 PM   #15
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A good fast 28mm such as f2 is very versatile especially when there is not a lot of room and low light situation. This is one of the many reasons that the FA 31mm limited 1.8 shines and I use that a lot indoor with flash. Without the FA 31mm, I will use the A 28mm 2.8 (manual focus).

As some of the other poster suggested, the 28mm prime is usually smaller and lighter for it is easy to carry for outdoor as well. Also, 28mm on APS-C camera makes it a commonly used focal length and easier to focus (shorter hyperfocal length).
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