[Archimedes the Dog]

Looking to get a K5 soon, doing a lot of portrait work lately and want to add an autofocus 50mm, the DA 50mm 1.8 and the FA 50mm 1.7 are widely available and see like good values, the DA runs cheaper, i assume because of impending full-frameism, any shame in going cheaper for the DA?

[Adam]

any shame in going cheaper for the DA?

Not really, as long as you can live with the plastic mount. In the long run you'll probably want to upgrade to a DA* 55mm or an 85mm, so going for the cheaper 50mm option now makes a lot of sense.

Also, if you don't mind manual focus, the Rokinon/Samyang/Bower 85mm F1.4 is another great portrait lens.

[Archimedes the Dog]

I currently use a 55mm K manual focus and love the characteristics of that lens, but I'm finding myself encouraging my subjects to move more on the stool and the autofocus is getting critical.

Good point on the *.

---------- Post added 08-24-15 at 12:50 PM ----------

There's also the F, which gets similar kudos. Pentax is always great at the fast 50, of course.

[AldaCZ]

I have used this lens trough the whole con but sometimes I switched to DA40 because of the AF and 10mm wide. I'm also thinking about a 85 mm even MF. Would it be easier than with a 50? (shallower DOF) I have ca 95% of the shots in focus. Smost the the time without CIF and even without glasses

Pentax M50/1.7 @1.7



there was a guy with DA50 and it's nerly the same Sans AF - which is good

MF of moving is hard, Use CIF then.

JUst MF and a bif of luck

[6BQ5]

I always thought that the DA 50mm f/1.8 was just an updated version of the F/FA 50mm f/1.7. Same basic formula. Is this true?

[Archimedes the Dog]

I always thought that the DA 50mm f/1.8 was just an updated version of the F/FA 50mm f/1.7. Same basic formula. Is this true?

One would imagine, except with plastic mount? What's the difference between the F/FA? Edit: looks like mainly the electronics as they relate to MTF, which i never use.

[boriscleto]

The DA seems to have changed the optical formula a bit.

FA


DA


The F/FA have a recessed front element reducing the need for a hood, but the DA probably has better coatings. The main advantage of the F/FA is the aperture ring.

[6BQ5]

It took me a while to figure out the difference. The spacing between the 2nd and 3rd elements from the left is different.

In addition to updated coatings, I would imagine the DA uses updated glass material, maybe?

[UncleVanya]

The F/FA have a recessed front element reducing the need for a hood, but the DA probably has better coatings. The main advantage of the F/FA is the aperture ring.

I have the F 50 f/1.7 and while I don't have the DA 50 f/1.8 I have the other plastic fantastic (at least until sold) the DA 35 f/2.4. I find the DA 35 to be noisier than the F 50. I'm not sure if this is the case with the DA 50 - but the plastic construction seems related to the way the noise sounds in the DA 35 vs. the the heavier metal F 50 f/1.7.

Personally I would just buy the DA since it is crazy cheap on sale right now.

[ChristianRock]

Also, notice the joint between the 4th and 5th elements. It is curved - more expensive to make, but it is said to give better OOF rendering (that is what the 50 1.4 lenses always have). The front elements have different shapes and the 50 1.7 is flatter.

I went through this decision process just recently and I went with the F 50 1.7, because of performance wide open (I also have M 50 1.7 so I knew what to expect). Pictures I see from DA 50 1.8 aren't as sharp wide open, but have better bokeh at any apertures including wide open (that's probably where that curved join comes to play).

So the decision is, what is more important? Bokeh or performance wide open? That will drive your choice. It drove mine.

[ScooterMaxi Jim]

In general, I'm finding the older lenses rendering a little less contrast and saturation, and at least the appearance of greater relative sharpness in the corners. While the optical design isn't necessarily different (they almost certainly are not different), the actual size of glass, changes in glass technology and coatings apparently have an effect. Overall, the DA provides a sharper look for a particular subject in the frame, but the older lenses will tend to provide a more pleasing look for both landscapes and portrait work. You would think the bokeh would be considerably different due to the change in aperture design, but I don't see improvement in that regard. Possibly the greater contrast in the DA reveals a bit of roughness in the out of focus areas (but not much).

[UncleVanya]

View image in gallery

F 50 f/1.7 bokeh is pretty good so I don't think that the DA would sway me in that aspect. But it is CHEAP. I got my F version for a steal so I jumped on it. But at this point I would gladly snap up the DA if I didn't have the F.

[mwilky55]

Not really, as long as you can live with the plastic mount. In the long run you'll probably want to upgrade to a DA* 55mm or an 85mm, so going for the cheaper 50mm option now makes a lot of sense.

Also, if you don't mind manual focus, the Rokinon/Samyang/Bower 85mm F1.4 is another great portrait lens.

Gee Adam....just read two different posts in five minutes and in each you endorsed the Samyang/Rokinon 85 f 1.4..

Tempts me to replace the one I just sold, but then I remember I have some other good lenses and i wasn't using it that much.

It's great, though, to have such a high quality, affordable lens available, which drew me to it in the first place.

[Na Horuk]

DA pros: - Newer coatings
- short focus throw, means AF can move faster (probably)
- rounded aperture blades
- light, small
- made of plastic (this one could be listed as pro or con. Plastic used to be treated as dirt, but these days plastics are fairly tough and can allow a lens to "bounce", instead of bending if it were made of metal. Its a thing of taste, some prefer metal, others prefer plastic - and seems plastic is the future)

FA pros: - aperture ring (might be required if you want to shoot on older film SLR or use certain macro tubes or bellows, lens reversals)
- slightly longer focus throw (probably. Maybe someone measured? Still not as long as older, fully manual lenses)
- heavier, sturdier build
- distance scales (DoF scales? or are DoF only on even older models?)

I think all 50mm f1.7 since M series up to DA 50mm f1.8 use basically the same optical formula. Now, of course there were changes in the manufacturing process (factories moved, new employees), materials (material regulations change, new materials are invented, etc.), and possibly even small changes in the optical formula itself (some elements curved differently, closer or farther apart, but we don't really know - those lens diagrams we see are only for marketing purposes, not actually perfectly accurate representations, not technical drawings). Its a good optical design, makes a very compact, but still bright and sharp 50mm lens (might be a smidge over 50mm, actually)

Anyway, get the DA 50mm f1.8 for a fast, good quality, light, affordable, great IQ lens with full automation on modern SLRs. Get FA or F 50mm if you want AF and slightly more solid barrel, aperture ring. Get A for even tougher build, lens made to last, with auto aperture, but MF. Get M series if you want manual, affordable, but all metal and still great image quality. If you put these lenses side to side, I doubt you would notice much difference. Main differences are that newer lenses have better flare resistance (though, with a lens hood, older 50mm won't have a big problem with this, either), maybe better contrasts. And the DA 50mm has rounded aperture blades, so its bokeh might be more round (but gives fewer starbursts on point light sources).
When I was looking for a Pentax 50mm, the DA wasn't out yet and a new FA was oddly expensive in this part of EU. So I got a M 50mm, and it serves me well enough. Today, I might think about getting a DA instead, since you can find it for really low prices and get full automation.

[Archimedes the Dog]

Also, notice the joint between the 4th and 5th elements. It is curved - more expensive to make, but it is said to give better OOF rendering (that is what the 50 1.4 lenses always have). The front elements have different shapes and the 50 1.7 is flatter.

I went through this decision process just recently and I went with the F 50 1.7, because of performance wide open (I also have M 50 1.7 so I knew what to expect). Pictures I see from DA 50 1.8 aren't as sharp wide open, but have better bokeh at any apertures including wide open (that's probably where that curved join comes to play).

So the decision is, what is more important? Bokeh or performance wide open? That will drive your choice. It drove mine.

Thanks, sharpness is preferable here. How much is the difference?