[gamgee]

Is there significant difference (apart from f 0.3) between these two lenses.?
I think there should be, why would Pentax make two so similar lenses?

[Lowell Goudge]

Is there significant difference (apart from f 0.3) between these two lenses.?
I think there should be, why would Pentax make two so similar lenses?

it is more like 1/2 stop not 1/3, (actually .47 to be exact but who cares about precision anyway.

This alone, i.e. a 50% increase in shutter speed is significant in low light. Otherwise, the advantages are in order of importance
- shallower depth of field when wide open on the 1.4 this is more important for portraits, and with the crop factor of a DSLR, the 50mm is becoming somethign of a portrait lens.
- brighter view finder
- probably sharper "sooner" i.e. achieves better sharpness perhaps at a lower F stop than the F1.7

fast 50mm lenses are a sought after item.

[ghost]

fast 50mm lenses are a sought after item.

Your telling me! I got mine recently (the FA 50mm f1.4) and I have trouble putting my other lenses back on my camera! now I really want the two f2.8 lenses just to make me happy! I think I could settle for the 16-50mm f2.8 for now though

[fearview]

Is there significant difference (apart from f 0.3) between these two lenses.?
I think there should be, why would Pentax make two so similar lenses?

---

they have different numbers of blades i think. and it will affect about how the bokah will be create.

i dont have m 1.4, but i have it predecessor the k 1.4, but in the other hand i have 2 (two) m 1.7, which in mint shape. i use them a lot. theyre so competitive, even if have to compare against the FA 1.4

samples


k10d + smc k 50mm 1.4


k10d + smc m 50mm 1.7

i know it not suite the topic since we talking about m 1.4 not k 1.4. but i think theyre pretty much the same glass.

[jsherman999]

The M 1.7:
-------------
Optical Formula 6 elements in 5 groups
Aperture Range f/1.7 ~ f/22
Number of Aperture Blades 6
Minimum Focusing Distance 0.45 m
Maximum Magnification 0.15 X
Filter Diameter 49 mm
Maximum Diameter 63 mm
Length 31 mm
Weight 185 g

The M 1.4:
-------------
Optical Formula 7 elements in 6 groups
Aperture Range f/1.4 ~ f/22
Number of Aperture Blades 8
Minimum Focusing Distance 0.45 m
Maximum Magnification 0.15 X
Filter Diameter 49 mm
Maximum Diameter 63 mm
Length 37 mm
Weight 235 g


From----> Pentax "Normal" Prime Lenses


It's been my experience owning both that the 1.7 is sharper at 1.7 and 2.0 than the 1.4, but they pretty much even out after that. The 1.4's bokeh is superior, although I've grown to like the 1.7's sometimes weird bokeh a lot.

[gamgee]

Thank you Sherman, that's exactly what I wanted to know...

[k100d]

Stan's Pentax Photography has a great discussion on Normal Length Primes.
they really like the M50 1.4 because of the handling and speed. Although most people say the 1.7 is sharper, i'm not sure if this is necessarily true. I used to have an M50 1.4 and i really liked it while i had it, but i needed the AE features.

[felix68]

Stan's Pentax Photography has a great discussion on Normal Length Primes.
they really like the M50 1.4 because of the handling and speed. Although most people say the 1.7 is sharper, i'm not sure if this is necessarily true. I used to have an M50 1.4 and i really liked it while i had it, but i needed the AE features.

I have done testing with the FA 50mm 1.4 and the F 50mm 1.7. Of the Copies that I had, the 1.7 was sharper at 1.7 but I could not tell the difference at f2.8. The difference at f2 was very difficult to discern but the 1.7 won out slightly in my opinion. This is in reference to the extreme edges of the shots. The center sharpness was indistinguisable, again in my opinion.
There is a difference in bokeh, with the 1.4 winning out and I found that for portraits, the slight border softness is a benefit, not a detraction. The 1.7 has slightly more contrast up to f2.8. I like the color rendition of the 1.4 better for some reason.
That is my experience with these 2 in terms of use for photography. I sold the F 50mm 1.7 and will never sell the 1.4.
YMMV, take with a grain of salt, IMHO, etc....

[deudeu]

There is another significant difference: the price.

On average, I think that the price difference is between $30 and $40 (the 1.4 being more expensive)... Still two cheap, great pieces of glass (at least the 1.7, i have never touched a 1.4)