[Marc Sabatella]

I thought this was a tokina lens... why would it drive anyone to Pentax?

You have it backwards - it's Tokina that licenses the Pentax patent on this design, not the other way around. Same with most of the other lenses offered by both companies.

[Clambake]

Wow. I need to start off by thanking everyone for the insightful replies. Pentax should thank you all, as this is forum and community is honestly one of the reasons I decided to choose Pentax over Canon, Nikon, etc.

First off, the exposure plot software or something equivalent was a great idea. I split up my library into smart albums in Aperture 3 to find that the large majority of my photos were taken in the 45-55mm range, with quite a few in the 35-45mm range as well. Regrettably, I've just recently been putting the 55-300mm through its paces, so not so many photos in that focal range yet.

I'm still interested in that Vivitar 105mm, but there's no way I'll be able to find one for the forum's average price of $216, right? What's the deal with the lens price increases over the last couple years?

With the 50mms, I'm thinking either the FA 50mm f1.4 or the A 50mm f1.4. I guess it comes down to which I have the cash for.

[Docrwm]

Wow. I need to start off by thanking everyone for the insightful replies. Pentax should thank you all, as this is forum and community is honestly one of the reasons I decided to choose Pentax over Canon, Nikon, etc.

First off, the exposure plot software or something equivalent was a great idea. I split up my library into smart albums in Aperture 3 to find that the large majority of my photos were taken in the 45-55mm range, with quite a few in the 35-45mm range as well. Regrettably, I've just recently been putting the 55-300mm through its paces, so not so many photos in that focal range yet.

I'm still interested in that Vivitar 105mm, but there's no way I'll be able to find one for the forum's average price of $216, right? What's the deal with the lens price increases over the last couple years?

With the 50mms, I'm thinking either the FA 50mm f1.4 or the A 50mm f1.4. I guess it comes down to which I have the cash for.

Prices are up because there are more Pentax shooters and for the M42s other company's have converters too.

If you do go with the FA50/1.4 get a good hood for it as the front element on it is VERY exposed and is therefore more prone to flare than most primes. But, the good news is a hood clears that right up and you have an excellent low-light fast 50 with AF!

[northcoastgreg]

Right now though I think the A50 f1.7 is way overpriced

keh.com is selling an A 50/1.7 for $76. I would not regard that as over-priced.

I'm still interested in that Vivitar 105mm, but there's no way I'll be able to find one for the forum's average price of $216, right?

Probably not. When I was following this lens on ebay a year ago prices for it were in the $300 to $400 range. It's probably gone up since then. Generally speaking, unless you are real lucky, most macros with 1:1 magnification will cost $300 and up.

Whether to choose an A version of a 50mm lens or an FA 50/1.4 depends on one's style of shooting. If you need to shoot quickly, AF becomes rather important. I regularly use manual focus lens for landscape and close-up photography, but if I'm shooting wildlife or candid portraits, I find AF very desirable.

[abacus07]

After going thru the entire macro lens club thread I developed an LBA for a panagor 90mm (or one of the variants). It will have to wait for now since I got a Pentax M 50Macro for $60. But the panagor seems to be in the $200 range. https://www.pentaxforums.com/userreviews/Panagor-90mm-F2.8-Macro-PMC-for-Pentax.html

I like shooting with primes because it can force me to compose differently and a lot of times I get great shots that I wouldn't have otherwise taken/seen. For example 50mm is a tough focal length for me as a walk around lens but I continue to produce keepers with it. And some of them are great.

[Ira]

For example 50mm is a tough focal length for me as a walk around lens but I continue to produce keepers with it. And some of them are great.

I think a lot of it also has to do with WHERE we each do our walking around. I live in the sprawling space of suburbia hell, so my 50s suit me better for the subjects at hand.

But I shot at an outdoor farmer's market awhile back...narrow aisles and lots of people...and it was the 35 all the way. (And I could have gone wider.)

BTW:

I had the Tamron 90 macro last year (it was a company lens and I had to give it back), and I loved the thing--even more so as general use, not just macro.

[RioRico]

Hey Ira, long time no see! How's tricks?

We've chewed this over a bit already. IMHO the FA50/1.4 is a Must-Have; more 50's are Nice-To-Have but they can wait, unless some jump out and scream, BUY ME CHEAP! A good 28-31 is also a Must-Have -- my walking lens now is the Komine 28/2 CFWA that cost me US$18.

Going longer and closer, a 90-105 -- a macro lens, or just a short tele with a Raynox on it -- is damn handy, and a good cheap 135/2.8 can fill in there; but a cheap bellows and some 75-90-105-140 enlarger lenses can do the same for very little money. My lens-of-the-day today is a GoldE Anastigmat 127/3.5 projector lens that cost me two bucks.

For pushing creativity cheaply, slower lenses are great implements. But the FA50/1.4 is THE place to start.

[Ira]

Hey Ira, long time no see! How's tricks?

Thanks for asking, but things haven't been great.

I continue to survive just to annoy my wife.

[RioRico]

I continue to survive just to annoy my wife.

I just swap that around.

[Clambake]

I guess the question for me comes down to which focal length is autofocus most useful for. I really like that Panagor 90mm and FA 50mm 1.4, but wouldn't a 100mm AF lens be more useful than a 50mm AF lens?

I personally have no idea, just wondering what people think on the matter.

[abacus07]

I think it depends more on what you plan on using each lens for and less on what the focal length is. For me it also depends on how much it costs to upgrade from a MF 100ish mm macro to an AF 100ish mm macro. IIRC the vivitar 105mm macro was not AF (but auto aperture). You might spend your entire budget (or more) on an AF 100ish mm macro.

[RioRico]

I guess the question for me comes down to which focal length is autofocus most useful for. I really like that Panagor 90mm and FA 50mm 1.4, but wouldn't a 100mm AF lens be more useful than a 50mm AF lens?

Y'know, that is a Very Good Question. Which means, I dunno either.

My one and only AF prime is the FA50/1.4. My AF zooms are various: very wide to very long. When I use those zooms at any focal length from 10mm to 500mm, AF is handy. I use my zillions of MFLs because 1) they're cheap, 2) they're interesting, and 3) they make me see the world as they do. Only item (1) necessarily separates AFLs from MFLs. And I often depend on catch-in-focus -- CIF is sorta the non-rich person's AF.

So I think the crunch, the deciding factor, with AF isn't focal length as much as it is BUDGET. And whether your subjects move around much. Would I turn away from any AF Ltd's? HA! Gimme one and I'll use it gladly!

So, to your question: AF is very useful at 50mm. And at 20mm. And at 100mm. And at 375mm. If your subject is dynamic, AF is useful. And if you're shooting macro (1:2 or greater), AF is useless IMHO.

[Just1MoreDave]

The prime focal lengths from about 70 to 135mm are really lacking for AF lenses. Most of the existing ones are macros, which are all fine lenses. But people who buy them for a multi-purpose AF lens find out that the AF is slow, part of the design of a macro lens. So they are sometimes unhappy with the main feature they bought the lens for. When I want AF in that range, I rely on a decent AF zoom. It limits me to f4 maximum, though.

Come to think of it, the MF on my Panagor 90/2.8 is pretty slow too. It's 2 3/4 turns from infinity to 14" (minimum distance). The focus ring turns the opposite way of the typical Pentax lens so I often start to turn it the wrong way first. Mine also requires some effort. For general use, I got a Tamron Adaptall-2 90mm f2.5 52BB. If you really scour eBay, you can get one of these for cheap with a mount that no one is looking for, and a PK/A mount elsewhere. It only does 1:2 by itself and above f11, sensor reflections off its big flat rear element make a purple spot on your photos. But it's awesome from f2.5 to f11.

[Clambake]

Okay, I think I've decided on the FA 50/1.4 (AF) and some MF 100mm or so lens. There seem to be lots of viable options around the $200 mark - I guess I'll just use the lens database and look for good deals down the road.

Dave, thanks for the good info on that Panagor. For everyday use, 2 3/4 turns does seem like a lot, but it would be a great lens for macro use only. I'm thinking maybe something more like that Tamron 90/2.5 you mentioned, or maybe this Makinion 135/2.8. It looks like there are lots of possible options from third party manufacturers.

[mekitties]

Well, most primes offer larger apertures than most zooms, giving you the possibility of shallower DOF. That's the main new creative element. Also, by removing the possibility to change FOV - which many photographers use a way of getting kind of sort the composition they want without having to change position - you are forced to think about compositions that do involve a change of position. Of course, it would be better still if you went ahead and changed position first, then still had the ability to change FOV. So really, it can be the case that primes teach you how to use zooms more creatively.

Primes also encourage you to look at the world differently - through a set of "blinders" locked into a given FOV - and perhaps noticing photographic possibilities you otherwise would have missed.

Not saying any of these are compelling enough reasons in themselves, but they are quite real.

But the answer to the OP's question is simple: the primes to get are the ones in the focal lengths where, for whatever reason, your zooms aren't cutting it. if you take so many pictures at 50mm and think that a faster/sharper/smallerwhateverer lens would make those better, then by all means, get a 50mm prime. Personally, that's one of my *least* used focal lengths on APS-C, though.

well said Marc!