Pentax 50MM F1.7 SMC F Thoughts and opinions...

[Scottie137]

I did search but aside from a few general posts in which this lens was mentioned, I didn't see anything specific. Just wondering how this lens performs, what the "sweet spot" is for the aperture on a APS-C sensor, how the bokeh is, etc. Thanks in advance for any opinions....

[jsherman999]

Originally Posted by Scottie137

I did search but aside from a few general posts in which this lens was mentioned, I didn't see anything specific. Just wondering how this lens performs, what the "sweet spot" is for the aperture on a APS-C sensor, how the bokeh is, etc. Thanks in advance for any opinions....

The F 50 1.7 is a very sharp, contrasty lens. I like it as much or more than the FA 50 1.4.

The bokeh isn't as smooth as the 50 1.4, and the colors can be a little cooler, but it's a sharper lens at the larger apertures (f/1.7 to f/2.4) after that they even out.

Still - I love the bokeh, it can be beautiful and interesting.

Lots of shots are in this thread - The F-Club.


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[newarts]

Originally Posted by Scottie137

I did search but aside from a few general posts in which this lens was mentioned, I didn't see anything specific. Just wondering how this lens performs, what the "sweet spot" is for the aperture on a APS-C sensor, how the bokeh is, etc. Thanks in advance for any opinions....

I'm pleased with its performance on my K100D; fast, accurate focus, good image quality. Bokeh seems fine.

I shoot mostly candid interior people wide open with it. A faster version would have less DOF - the 1.7 seems a reasonable balance of speed & DOF.

I got it in preference to faster one because I often use it with a Nikon TC-15ED teleconverter which makes it a 75mm 1.8 (a larger front element would cause vignetting with the teleconverter - a front type.)

I wish I had technical data and critical comparison photos for you and am eager to see such from others.

[Just1MoreDave]

It has the same optical formula as the M and A versions. The f1.7 lenses have a flatter field than the faster cousins, which is helpful. I suspect it makes AF a little more accurate. They also have a six-blade aperture, probably accounting for the bokeh differences. Bokeh is still decent, though bright points might be hexagons, not octagons. I've seen a couple of tests that show the f1.7s are a bit sharper than the f1.4s at about f2 and wider. Differences between the f1.7s and f1.4s are not very large in the real world.

Mine is a great performer. My only "complaint" is due to my preference for manual focus. The F50/1.7 isn't great at MF, with a thin focus ring that only turns 90 degrees and has no damping. I have a Pentax-A 50/1.4 that is so much nicer for MF, but when I need AF, I take the F50/1.7.

Another issue is price. When you can get the FA new for $200, it's not a good idea to pay a lot for the F50/1.7.

[axl]

I'm loving my copy of F50/1.7. It's stunning lens. Feels bit plasticky but: AF is fast and very accurate, In low light it's faster than DA40. Colours are great. And that sharpness, oh boy that sharpness. Very good at f1.7 and excelent between f2 and f5.6. I'll post some pics later today (I hope I won't forget). But if you can get it for good money, don't think twice, it's all right...
BR

[dopeytree]

I have a manual focus version k 50mm f/1.7 best lens I own!

Manual focus is easy after a while and it's amazing what you can achieve in lowlight with this thing!
I normally shoot at about iso 560 then add some noise reduction via ninja noise.

[Class A]

Originally Posted by axl

I'll post some pics later today (I hope I won't forget).

Don't forget.

Originally Posted by dopeytree

I have a manual focus version k 50mm f/1.7 best lens I own!

Great pics!
My favourite is the portrait of the beautiful woman.

[axl]

Originally Posted by Class A

Don't forget.

As promised, here are few examples from F50/1.7
f2 on K100D @ ISO200


f2.8 on K10D ISO 800


f2 on K10D ISO 200 (throuhg the glass, the lines in top right corner are scratches on the glass)


f4 on K10D ISO 200 (again through the glass)


Seriously, if anybody can get this lens for good money (and don't have other fast 50 in the bag already), there shouldn't be any hesitation. One of the best lenses I have...
BR

PS: have a look here (quite few shots from F50/1.7): The F Club!
and here: Pentax Lens Review Database - 50mm F1.7

[Scottie137]

Well, thanks for the feedback. I bought one today on KEH.com. they still have one left. Can't wait to get it!

[Class A]

Originally Posted by axl

As promised, here are few examples from F50/1.7

Nice shots, Peter!