28mm f/2.8 vs. f/3.5

[jackm1]

<p>Any thoughts on these two SMC-M lenses? Someone is selling an f/3.5 claiming it was soooooo superior to the f/2.8, true?</p>

[markus maurer]

<p>Usually the slower primes are optically the better ones, so yes.</p>

[c_wyatt]

<p>I don't think the above is always true, some of the slower primes are just cost-saving versions. And the f/2.8 is going to be better at f/2.8...</p>

<p>That being said: </p>

<p>f/2.8 rating is 8/10<br>

f/3.5 rating is 9/10<br>

<a href="http://www.pentaxforums.com/lensreviews/category-SMC-Pentax-M-Lenses.html">http://www.pentaxforums.com/lensreviews/category-SMC-Pentax-M-Lenses.html</a><br>

I do <em>not </em>fully trust that rating system but it's a useful guide to check out user reviews.</p>

[andrewg_ny]

<p>Not sure how many oooo's superior it is, though I've repeatedly read similar suggestions that the 3.5's are excellent. I've been kind of wondering about the slower 35mm's as well. I would wonder how the 3.5's compare wide open vs. the 2.8's are at f/4.</p>

[stemked]

<p>I've only owned the 28mm f2.8 M. I sold the lens because the focal length was well represented in other lenses I owned. Optically it is ok just nothing to write home about. The 28mm f2.8 M is very small and takes 49mm filters, which were IMHO the best reasons to own the lens (I used to bike ride with a Pentax P30T, 28mm f2.8M, 50mm f1.7A, 100mm f4 A macro and 80-200 f4.7-5.6 A + several 49mm filters . The 28mm f3.5 is a larger lens, but I've heard tons of people who are ga-ga about it and cannot say the same thing about the f2.8.</p>

[nealcurrie]

<p>It's true from the reports I've seen; the 3.5 is sharper than the 2.8. However, the SMC K 1:3.5/28mm is sharper than all of them. It is also much larger though, and has a 52mm thread.</p>

[james_gay]

<p>Keep in mind that the faster the lens, the more light is transmitted to your focusing screen under low light conditions. As such, it's easier to detect set-up focusing issues and correct for them.<br>

<br />I like the 28mm focal length and have an SMC M-28/2.0 and a Tak M42 28/2.8. I pair them to a K-7, or K-x using 'Catch-in Focus'. For convenience, my preference is the 28/2.0. I don't use them for MACRO, but they are every bit as sharp as I want them to be... even at full aperture.<br>

<br />Cheers...</p>

[jgredline]

<p>I have a few 28mm lenses myself. It is a tad long for me, but a good focal length.<br>

I do have the SMC-A 28F/2.8 but it is useless at F/2.8. At F4.0 it is leaps better, but it is nothing to write home about. The best 28MM lens I have is the Tokina EL-28F/2.8 and this lens wide open is pretty dang good. It is my most used 28mm lens when I need this size. Behind that one, I have a sears 28 that is also great and has the ''A'' contacts as wel.</p>

<p>Having said that, I have heard over and over again that the SMC-A 28 F/3.5 is the way to go. People swear this is the best one, but i have not tried one and likely will not since I do not use this focal length much.</p>

[User_502260]

<p>I don't remember seeing the 28/3.5 M lens for sale in the U.S. when it came out. I think the early 28/3.5 K lens was the same optically as the earlier 28/3.5 SMC M42 model, which was a very good lens. My 28 M is the f/2.8 and seems to work well. In fixed mount 28mm K lenses I also have the 28/2.5 Vivitar and the 28/2 Vivitar (22XXX...). I would say the 28/2 Vivitar is my favorite. </p>