[axelm7]

I recently bought a K-50 with the kit 18-55 DA L WR lens, which has provided me with decent shots but is useless wide open from 24-55mm and I have some spare change so I'm planning in getting a fast MF prime from the film era. However, there are so many options that I've gone over reviews and prices on eBay for a great deal of lenses and I narrowed it down to a couple of lenses. I'm looking for a something ranging from f/1.4 to f/2.8 that delivers the best sharpness wide open (I know all fast primes are soft wide open), good build quality/focus ring and under $100, here are my options:

-Pentax-A 50mm f/2.8 Macro (heard good things about this wide open; over my budget though)
-Pentax-M 50mm f/4 Macro (cheap, but slow for a prime)
-Pentax-M 50mm f/1.4
-Pentax-A 50mm f/1.7
-Pentax-M 50mm f/1.7
-Vivitar 55mm f/2.8 1:1 macro

Price-wise, it seems like the best bang-for-buck is the Pentax-A f/1.7, although the Pentax-M f/1.4 is said to be sharper at f/1.8. The A 2.8 macro seems like the best of the bunch here in terms of sharpness and macro capabilities, but the only listing of it I found was going for $200, is it worth waiting and saving up for it? Lastly, the Vivitar has rave reviews but I found no listings of it anywhere, and it seems to be cheap for what it offers, so if anyone can help find one or sell it to me, it'd be great.

[stevebrot]

although the Pentax-M f/1.4 is said to be sharper at f/1.8

Groundless rumors. Both the M and A series 50/1.7 lenses are sharper at wider apertures* than their 50/1.4 stablemates. The M and A series lenses are optically the same. What the A series lenses give you is full exposure automation. If you are planning on using the lens with bellows or (most) extension tubes or reversed, the presence or absence of the A contacts should not be a consideration.

My recommendation is sort of mixed because your requirements are sort of at odds, but here it is:

• Any of the dedicated macro lenses for macro. That being said, the DOF for portraits, even wide open may not work as well as you might like.
• Forget the f/1.4 lenses if you want sharpness wide open. I know that me saying this will bring a flood of "sharp" example photos from owners of A and M f/1.4 lenses, but this was known when the lenses were new back in the 70s and 80s and was documented in lens tests back-in-the-day. A reduction of both resolution and contrast is the penalty paid for that extra 1/2 stop light gathering ability.
• My pick would be the M 50/1.7. Its build is much better than the A 50/1.7 (I own both) and it offers excellent sharpness as well as adequately narrow DOF for portrait work. I used mine on bellows for macro work before I bought my dedicated macro lens. It is also probably the least expensive of the lenses on your short list.

Steve

* The f/1.4 lenses are fairly soft wide open and remain so relative to the f/1.7 lenses until about f/5.6 at which point and narrower the two are equivalent.

[axelm7]

Groundless rumors. Both the M and A series 50/1.7 lenses are sharper at wider apertures* than their 50/1.4 stablemates. The M and A series lenses are optically the same. What the A series lenses give you is full exposure automation. If you are planning on using the lens with bellows or (most) extension tubes or reversed, the presence or absence of the A contacts should not be a consideration.

My recommendation is sort of mixed because your requirements are sort of at odds, but here it is:

• Any of the dedicated macro lenses for macro. That being said, the DOF for portraits, even wide open may not work as well as you might like.
• Forget the f/1.4 lenses if you want sharpness wide open. I know that me saying this will bring a flood of "sharp" example photos from owners of A and M f/1.4 lenses, but this was known when the lenses were new back in the 70s and 80s and was documented in lens tests back-in-the-day. A reduction of both resolution and contrast is the penalty paid for that extra 1/2 stop light gathering ability.
• My pick would be the M 50/1.7. Its build is much better than the A 50/1.7 (I own both) and it offers excellent sharpness as well as adequately narrow DOF for portrait work. I used mine on bellows for macro work before I bought my dedicated macro lens. It is also probably the least expensive of the lenses on your short list.

Steve

* The f/1.4 lenses are fairly soft wide open and remain so relative to the f/1.7 lenses until about f/5.6 at which point and narrower the two are equivalent.

Thank you Steve, I also thought my best option was the M f/1.7, and I don't mind the missing auto-aperture, as it will help me learn to use all-manual lenses. Is the Pentax A 2.8 worth the price though?

[baro-nite]

I also thought my best option was the M f/1.7, and I don't mind the missing auto-aperture, as it will help me learn to use all-manual lenses. Is the Pentax A 2.8 worth the price though?

All of the lenses on your list are good. I agree that the M50/1.7 can be good for both portraits and macro, and can be a very good bargain as well (can be found for US$50 and maybe less). However, there are distinct inconveniences to using a lens like this for macro. You aren't going to find one lens that is ideal for both (unless your taste runs to brutally sharp portraits).

[axelm7]

All of the lenses on your list are good. I agree that the M50/1.7 can be good for both portraits and macro, and can be a very good bargain as well (can be found for US$50 and maybe less). However, there are distinct inconveniences to using a lens like this for macro. You aren't going to find one lens that is ideal for both (unless your taste runs to brutally sharp portraits).

I will probably get an extension tube for it as well as a backward mount for macro work. For portraits all I want is the shallow DOF and decent sharpness from f/1.7 to f/4, not razor-sharp f/8-f/16 portaits.

[lytrytyr]

The M and A series lenses are optically the same.

Same scheme, but the cemented join on the M is flatter than on the A.

Here's the M courtesy of Boz Dimitrov:



and the A/F/FA:



---------- Post added 07-14-14 at 08:42 PM ----------

You aren't going to find one lens that is ideal for both (unless your taste runs to brutally sharp portraits).

The ZK 50/2 Makro-Planar gets close to the ideal, but not within OP's budget.

[maltfalc]

best 50mm i've ever owned, and i've owned a few.
Revuenon 50mm f1.4 MC Lens Reviews - Miscellaneous Lenses - Pentax Lens Review Database

[Nick Siebers]

One question - why insist on sharpness "wide open" when comparing lenses with different maximum apertures? Any of the the 50/1.4s and 1.7s will be plenty sharp at f/2.8, where the A 50 macro starts. Of course, if you want a lens to do macro as well, a dedicated lens comes in handy. The M 50/4 is an incredible bargain for IQ vs. price, although using the early lenses have their disadvantages. The Vivitar is a great lens as well, although pretty bulky and hard to find. I sold mine a while back when I got an F 50/2.8 macro.

In summary:
Best bang for buck: M 50/1.7
But I don't like using the green button: A 50 1/1.7
But I want the best bokeh at a low price point: M 50/1.4 or K 50/1.4 (shameless plug, I have on in the MP)
But I want to do macro with the lens and not fiddle with extension - you can't really go wrong, anyone who troubles to make a macro lens makes it well.

Good luck! Nick

[pinholecam]

The 'wide open' criteria is a bit hard to tie down.
Some of your options are f4 wide open while others are f1.4 or f1.7.

The 50/1.7 has more even sharpness thru the frame from f1.7.
In the center area, I never found it to be sharper than the f1.4 at f1.7 (and I had all the 50mm f2,f1.7,1.4 in A and M versions as well as the FA)
This boils down to their lens design differences.
By f2.5, my A50/1.4 is very sharp in the central area, getting more evenly distributed sharpness by f4.


In summary :
Best bang for buck : M50/1.7 (on a budget, very few things can beat it, even my Rollei 50/1.8 can't; but hexagon OOF highlights by f4)
Best : M50/1.4 (spend that money once, get the most versatile one of the lot and be done with it)
Macro : Then you need a macro lens

A50/1.4 at f4 (I also left a very large copy on my flickr if you want to see how sharp it is)






A50/1.4 at f2

[Kozlok]

Stopped down a bit, all of these lenses are very very sharp. Also, as pointed out, the macro lenses and the fast lenses are just different animals. You will need them both eventually, so decide which you want first. For a Macro, F4 is plenty sharp because you'll be stopped down to f8 at short distances most of the time anyway. That said, 50 is really too short for an "only" macro. Save up for something longer. For the fast lenses, I would strongly suggest looking at samples online of the f1.4 lenses and the f1.7 lenses and choose based on rendering more than sharpness. I chose the 8-Element Super Takumar 50/1.4. I like its old-school single coated look, mostly because it's quite different than all my other lenses. I've shot the 50/1.7, and I think if I were getting a K-mount 50, it'd be the 1.7. I really like the way it handles the light.

One more thought, there is a thread on here called the Traveling Nifty 50mm. You sign up on the list and an A-50/1.7 will eventually show up at your house. You use it for a week or so and pass it along. I did it, and it was such a treat to be involved, and I fell in love with the lens!

Some of my faves;
Super Tak 50/1.4:




Here's one showing the softness at f1.4 close up. It really works for the subject sometimes. Really, sometimes sharpness isn't the most important thing!




Here are a couple from the A50/1.7:






Here's a simple shot that shows the Tak vs the A. The A is much more saturated and contrasty. The Tak looks more like a film shot, and has a bit of swirly bokeh.

Tak:

A:

[axelm7]

best 50mm i've ever owned, and i've owned a few.
Revuenon 50mm f1.4 MC Lens Reviews - Miscellaneous Lenses - Pentax Lens Review Database

Your shots look pretty great, what aperture do you use most often with this? Found a couple examples on eBay but they were all in Europe and I live in NA, shipping costs are expensive and customs may charge me for the package, so I'll have to wait till I find a well-cared-for example at a nice price.

[dms]

I have the 50mm f/4 macro (K) and the 50mm f/1.7 (M).
-- Both are excellent wide open, and have great "feel" although the macro is nicer.
-- The macro is of course a macro and thus more convenient for close up--to m=0.5 (e.g., flowers). The 50mm f/1.7 is also excellent as a macro--but you need to add extension (tubes/bellows/TC).
-- For backpacking/walking through museums my choice of the two is the macro. For theater/low light the f/1.7. Basically comes down to:
-- 50mm f/1.7 faster and quite a bit sharper (at longer distance) and very inexpensive lens lens versus
-- 50 mm f/4 more convenient for macro, and more expensive lens.
In my mind the 50mm f/1.7 (M) [and the 35 mm and 28mm f/3.5--super takumar thru K] are the best Pentax lenses when price is a significant part of the evaluation. And if you don't know/macro is not a huge consideration I would start w/ the 50mm f/1.7 (M)

[axelm7]

Same scheme, but the cemented join on the M is flatter than on the A.

Here's the M courtesy of Boz Dimitrov:



and the A/F/FA:



---------- Post added 07-14-14 at 08:42 PM ----------



The ZK 50/2 Makro-Planar gets close to the ideal, but not within OP's budget.

How does the flatter join affect the lens though?

One question - why insist on sharpness "wide open" when comparing lenses with different maximum apertures? Any of the the 50/1.4s and 1.7s will be plenty sharp at f/2.8, where the A 50 macro starts. Of course, if you want a lens to do macro as well, a dedicated lens comes in handy. The M 50/4 is an incredible bargain for IQ vs. price, although using the early lenses have their disadvantages. The Vivitar is a great lens as well, although pretty bulky and hard to find. I sold mine a while back when I got an F 50/2.8 macro.

In summary:
Best bang for buck: M 50/1.7
But I don't like using the green button: A 50 1/1.7
But I want the best bokeh at a low price point: M 50/1.4 or K 50/1.4 (shameless plug, I have on in the MP)
But I want to do macro with the lens and not fiddle with extension - you can't really go wrong, anyone who troubles to make a macro lens makes it well.

Good luck! Nick

I think the price difference means the M gets the win for me. Might have to get a longer focal length dedicated macro later, but I haven't found too many good options in the 85mm-135mm range, any suggestions?

The 'wide open' criteria is a bit hard to tie down.
Some of your options are f4 wide open while others are f1.4 or f1.7.

The 50/1.7 has more even sharpness thru the frame from f1.7.
In the center area, I never found it to be sharper than the f1.4 at f1.7 (and I had all the 50mm f2,f1.7,1.4 in A and M versions as well as the FA)
This boils down to their lens design differences.
By f2.5, my A50/1.4 is very sharp in the central area, getting more evenly distributed sharpness by f4.


In summary :
Best bang for buck : M50/1.7 (on a budget, very few things can beat it, even my Rollei 50/1.8 can't; but hexagon OOF highlights by f4)
Best : M50/1.4 (spend that money once, get the most versatile one of the lot and be done with it)
Macro : Then you need a macro lens

A50/1.4 at f4 (I also left a very large copy on my flickr if you want to see how sharp it is)






A50/1.4 at f2

I just noticed the 1.7 jumps straight to 2.8, skipping f/2 altogether. And I also think I like the contrast in the 1.7 better, although the bokeh might look better on the super Tak.

---------- Post added 07-14-14 at 11:00 PM ----------

I have the 50mm f/4 macro (K) and the 50mm f/1.7 (M).
-- Both are excellent wide open, and have great "feel" although the macro is nicer.
-- The macro is of course a macro and thus more convenient for close up--to m=0.5 (e.g., flowers). The 50mm f/1.7 is also excellent as a macro--but you need to add extension (tubes/bellows/TC).
-- For backpacking/walking through museums my choice of the two is the macro. For theater/low light the f/1.7. Basically comes down to:
-- 50mm f/1.7 faster and quite a bit sharper (at longer distance) and very inexpensive lens lens versus
-- 50 mm f/4 more convenient for macro, and more expensive lens.
In my mind the 50mm f/1.7 (M) [and the 35 mm and 28mm f/3.5--super takumar thru K] are the best Pentax lenses when price is a significant part of the evaluation. And if you don't know/macro is not a huge consideration I would start w/ the 50mm f/1.7 (M)

Yeah, price wise I think it is the best, and I just found a decent copy of an M 50mm 1.7 and it comes attached to an ME Super body. I've never used a 35mm film SLR before, might have to get some film and see how that goes!

[stevebrot]

Same scheme, but the cemented join on the M is flatter than on the A.

These are the f/1.4, right? I was unaware, though it should not surprise me. The M, A, F, and FA 50/1.7 are all identical and I assumed the same for the f/1.4.


Steve

---------- Post added 07-14-14 at 09:54 PM ----------

I just noticed the 1.7 jumps straight to 2.8, skipping f/2 altogether.

Most (all?) Asahi/Pentax 50mm lenses have click stops at intermediate points between the marked numbers on the aperture ring. For the M 50/1.7 the clicks are at f/1.7, f/2, f/2.8, f/3.5, f/4, f/4.8 (I think), f/5.6, f/6.7, f/8, f/9.5, f/11, f/13, f/16, and f/22.

Yeah, price wise I think it is the best, and I just found a decent copy of an M 50mm 1.7 and it comes attached to an ME Super body. I've never used a 35mm film SLR before, might have to get some film and see how that goes!

Please do put that ME Super to work! It will likely need new light seals and mirror bumper foam, but that can be done as a DIY project. The good folk on the film slr section of this site are very helpful.


Steve

---------- Post added 07-14-14 at 10:08 PM ----------

Just for completeness, here is a macro taken with my M 50/1.7 on bellows. The reproduction ratio is about 2:1 and the subject is the petiole of a small vine maple leaf. Note what is probably a fungal filament on the side of the stem. Also note the very shallow DOF at that magnification. I think this was taken at f/16.



...and a 35mm film shot at portrait distance with the same lens (~f/8):




Steve

---------- Post added 07-14-14 at 10:24 PM ----------

The 'wide open' criteria is a bit hard to tie down.
Some of your options are f4 wide open while others are f1.4 or f1.7.

The 50/1.7 has more even sharpness thru the frame from f1.7.
In the center area, I never found it to be sharper than the f1.4 at f1.7 (and I had all the 50mm f2,f1.7,1.4 in A and M versions as well as the FA)
This boils down to their lens design differences.
By f2.5, my A50/1.4 is very sharp in the central area, getting more evenly distributed sharpness by f4.


In summary :
Best bang for buck : M50/1.7 (on a budget, very few things can beat it, even my Rollei 50/1.8 can't; but hexagon OOF highlights by f4)
Best : M50/1.4 (spend that money once, get the most versatile one of the lot and be done with it)
Macro : Then you need a macro lens

A50/1.4 at f4 (I also left a very large copy on my flickr if you want to see how sharp it is)






A50/1.4 at f2

Nice work with the FF Sony A7! Are you sure about the aperture of the Grand Mother photo? Based on the DOF, I would suspect about f/4 or even f/5.6. For comparison, see my B&W 35mm film photo (probably f/8) above.


Steve

[kh1234567890]

I went through this (and have a box of useless bodies which came attached to the lenses) - 50's attached to bodies are always cheaper on eBay than the lenses on their own

I started off with the A50/f2 which was boring, progressed onto A50/f1.7 which was better, got tempted by a Chinon 50/f1.4 which was more fun but not that wonderful and ended up with a M50/f1.4 which actually gets used. All for next to nothing if you wait long enough and snipe well (or don't mind having to take one to bits and clean off a touch of fungus). I'm still on the lookout for a really cheap 50/f1.2

I wouldn't use any of them wide open for macros though - DoF would be far too shallow and they can be hard to focus accurately with the stock Pentax screen anyhow.