[Digital Dustin]

Well I'm super addicted already and I really want a "fast 50" but I have been struggling on which one to get. Should I get the M,A or F? All this technical lens stuff gives me a headache. I tried doing a search here but almost every single thread ever in the history on this forum has '50mm' in it.

[pschlute]

Well I'm super addicted already and I really want a "fast 50" but I have been struggling on which one to get. Should I get the M,A or F? All this technical lens stuff gives me a headache. I tried doing a search here but almost every single thread ever in the history on this forum has '50mm' in it.

Have a look here for detailed specs on Pentax lenses Welcome to Bojidar Dimitrov's Pentax K-Mount Page

Basically you wont go wrong with image quality on any Pentax 50mm, but the series you choose will affect functionality (and price).

"K" and M lenses are manual focus and manual exposure.

A lenses are manual focus and auto exposure (as long as you leave the aperture ring on the "A" setting.

All later lenses will be auto focus and auto exposure.

The best value for money , and I think most will agree with me is the M 50mm 1.7
It is very plentiful on the second hand market, has exceptional image quality, and is going to be fast enough for 99% of your needs.

Dustin, what are we going to do with you, you'll be asking us what colour socks to wear next.

Do you want autofocus? If so, get the F or the FA.

If you want the option to autofocus or manual focus, get the F or the FA.

If you want to manual focus and aren't bothered one way or the other about autofocus, just get the first one that comes your way. Or the cheapest, you'll probably end up with more than one anyway.
I'm sure you'll be happy with whichever one you get.

[MoiVous]

So many lenses, so little time.......

One of the best things to do is read the Lens review section of the forum - lots of users experience to be had there and a rating as well.

There is also a lot of examples in the https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/71778-fifties-association.html
- dedicated to 50mm lenses (although some 55mm lenses creep in)

Personally, I've got an FA50mm f1.4 and love it, but lots of others swear by the A series 50mm f1.7.

Remember that big apertures often mean razor thin DOF, so you have to be careful.

On the other hand, that also gives some really nice bokeh. Have a look in Post your photos - https://www.pentaxforums.com/forums/post-your-photos/84099-abstract-christmas-tree-bokeh.html and https://www.pentaxforums.com/forums/post-your-photos/81702-people-kids-holida...s-content.html for some good examples of f1.4 50mm lens bokeh.

Good luck with the hunt.....

Cheers

[Rondec]

Depends a lot on what you think you want to do. You can save money going with a manual focus, manual metering lens, but particuarly a fast lens like a 50, you probably would need to consider installing a split screen to help focus it. The depth of field is really narrow at f1.4 and it is easy to misfocus.

[frascati]

Then the AF capability is a very strong plus in these 'fast' lenses?

[tokyoso]

Well I'm super addicted already and I really want a "fast 50" but I have been struggling on which one to get. Should I get the M,A or F? All this technical lens stuff gives me a headache. I tried doing a search here but almost every single thread ever in the history on this forum has '50mm' in it.

I think it depends on what you want from it. If you want build quality, you might want to look into the older generations or a DA*55 (sdm issues aside). For auto focus, only the newer gens. (F/FA/DA*)
if you like the older lenses build quality but want more except auto focus, then you want the A version which will let you use most of the metering modes (except it wont auto focus for you). I tried an A lens at a shop, its pretty cool, but it was marked at a considerable premium over here compared to the manual ones.
What you want to avoid is end up with a bundle of 50mm lenses, because you arent satisfied with one or another after a purchase.

[Just1MoreDave]

Then the AF capability is a very strong plus in these 'fast' lenses?

AF comes with its own problems. AF will find something to focus on, but it might be a person's ear instead of their eye. At f1.4 and close enough for a head shot portrait, the face will not really be in focus. It's hard to catch this in the viewfinder when it happens.

Because I'm cheap, I didn't get an FA 50/f1.4 - already had the A version. I stick with a Pentax-F 50mm f1.7 when I want AF. Being aware of the potential problems helps, and with a slightly larger DOF, the F50/f1.7 does very well, even with my older camera. So you can certainly use AF and it does work, it's just not perfect on its own.

[Marc Sabatella]

Another thing to note - if you expect you'll be doing a lot of MF anyhow, then a MF lens usually makes more sense, not just because it is a lot cheaper, but because the focus ring is designed for easy focusing by humans (long throw with decent resistance), as opposed to the AF lenses that are designed for easy focusing by computer-controlled motors (short throw with little resistance).

Within the world of manual lenses, just know that the "A" series allows full autoexposure capabilities, whereas the older series require you to use M mode and the techniques described in the sticky thread in this forum on how to use manual lenses. Quality wise, any of the f/1.7 or f/1.4 lenses are fine - but the "A" version of the f/1.4 will run almost as much as an autofocus version.

[Digital Dustin]

I dont think I'll have an issue with manual focus and the M seems like a great deal but what about the stop down metering. Is it a pain in the butt or not a big deal?

[Wheatfield]

I dont think I'll have an issue with manual focus and the M seems like a great deal but what about the stop down metering. Is it a pain in the butt or not a big deal?

It's not a pain in the butt until the metering fails.....
Which it will.
Any Pentax 50mm lens is a very good lens.

[er1kksen]

I dont think I'll have an issue with manual focus and the M seems like a great deal but what about the stop down metering. Is it a pain in the butt or not a big deal?

Working with a manual focus lens usually is, by nature, a somewhat slower and more contemplative way of working, and green-button stop-down metering fits into that just fine.

I'd recommend the M f1.7 as probably the best image quality and value of the bunch. When I don't feel like dealing with stop-down metering I just leave it wide open in Av mode, and while the depth of field is of course quite shallow (something I like most of the time anyways), the areas that are in focus are very sharp. Very little to no softening at wider apertures with the f1.7. I picked up mine on ebay for $35, and I consider it the best $35 I've ever spent.

[JeffJS]

Then the AF capability is a very strong plus in these 'fast' lenses?

Not necessarily. It doesn't hurt but the lenses are completely different animals. I tend to prefer manual focus and because of that, I've sold every FA50 I've ever owned staying in favor of the A50 lenses. Fast AF depends on so much more than the lens. The camera, the lighting, the actual subject, etc. The camera focuses by Contrast and if it cannot be found (black on black in a dim room for instance), the lens will hunt for awhile and then give up. That will be true with Any AF lens.

I dont think I'll have an issue with manual focus and the M seems like a great deal but what about the stop down metering. Is it a pain in the butt or not a big deal?

It doesn't take much to get use to. If you think it's going to bother you, then get an A50 lens (at least f1.7).

By the way, you won't be able to stop at just ONE 50mm...

[GoremanX]

My opinion real quick:

I LOVE my Super Takumar M42 50mm F1.4. It still looks brand new after 40+ years (I'm the second owner), the focus ring is a buttery dream come true, and since I rarely ever use anything other than Manual mode, the manual metering doesn't bother me one bit. Best of all, it was dirt cheap. The best pictures I've taken were with that lens. My only issue with it: 50mm isn't very wide on an APS-C camera.

[eyew]

Bought my K-X and started down the rabbit hole of hunting for cheap prime lenses.

Spotted the Helios 44-2 f2.0 for $20, bought it and before I even got my adapter from ebay, spotted the 50mm M f1.7 for $50 and also bought it.

Keep telling myself that should be it - no more looking now Am having heaps of fun with them and the K-X feels sooo light now compared to the zooms I had.

Not sure when I'd use the Helios now that I've got the f1.7 really, with the hassle of the adapter...

Two sample shots:
50mm M f1.7


Helios 44-2 f2.0: