Pentax M 50mm f/1.4 SMC

Pentax M 50mm f/1.4 SMC. If you’re looking to purchase this lens sometimes Adorama will have them and Ebay definitely will. It helps me if you purchase it through one of these links here in this review. When you purchase through these links it financially enables me to devote time to develop this site further. Thanks for the help! -Todd


8.3 oz (236g)

Focus Ring
Rubber on Metal.

Close Focus
1.55 feet (0.45 meters).

Filter Threads
49mm, Metal.

Aperture Ring

8 blades stopping down to f/22.

Pentax-M K Metal Mount.

Made in





100% Crop

f/1.4 | f/1.8 | f/2 | f/2.8 | f/3.5 | f/4 | f/8

Corner at f/1.4



Flare and Ghosting

Closest Focus at f/4

Wide open the lens is a little sharp, however you can not tell because of the very high amount of coma and chromatic aberration reducing contrast quite a bit.
f/1.8: Sharpens up a ton with better contrast but still has a lot of chromatic aberration.
f/2: Pretty sharp with good contrast and less chromatic aberration.
f/2.8: Very sharp with great contrast and color and only a little chromatic aberration.
f/3.5: Very sharp with very little chromatic aberration.
f/4: Super sharp all over with great contrast and no noticeable chromatic aberration.
f/8: Super sharp with no signs of diffusion until f/14.

A fair bit of vignette but is quickly reduced stopped down a tiny bit and is basically gone by f/2.8 for the most part.

The bokeh is pretty nice and not too distracting.

Flare and Ghosting
Flare is not too bad and is quickly reduced stopped down a tiny bit. The ghosting is noticeable but not annoying and has nice color and shape.


A very small amount of Barrel Distortion.

On AF Camera
Optics:          ★ ★ ★ ★
Mechanics:   ★ ★ ★ ★
Ergonomics: ★ ★ ★ ★
Usefulness:   ★ ★ ★ ★ ★
Availability:    ★ ★ ★ ★
Overall:          ★ ★ ★ ★

On MF Camera
Ergonomics:   ★ ★ ★ ★ ★
Overall:           ★ ★ ★ ★
Out of 5

This lens is solid and feels amazing to hold. It is very small even with caps on and is easy to carry around in your pocket. The lens is worth every penny and is a steal of a deal today. There are a ton of them out there so the price has dropped dramatically. Go looking for one and you will be very happy you did.
I have had a few copies of the lens which had mechanical problems so make sure you find a copy that has not been dropped or anything. The lens is a massive amount of glass in a small metal shell so things can break easily if not handled properly. However don’t be afraid to use it hard because it is still built very well.
Optically the lens is very soft wide open but stopped down around f/2.2-2.8 it begins to become usable on sunny days. I got carried away one sunny day and tried to shoot it feathering the aperture around f/1.6-1.7 for a really shallow depth of field but my images were too soft and had way too much chromatic aberration to use. However for night photography you can open this lens right up if you don’t mind the expected amount of coma.
Sharp sharp sharp! Stopping the lens down to only around f/2 will begin to give you really sharp images and by f/3.5 gives you super sharp results.
The lens has a bit of barrel distortion which is more then I had expected.
There is some ghosting but the flare is not too bad.
Vignette is heavy wide open but quickly reduces and is almost gone by f/2.8 which is really good.
The bokeh is pretty nice and smooth at all apertures which makes for a nice portrait lens. I was hoping it would be a little better but for the price I can’t complain.
If you want one just get one. When I bought my first SLR camera I borrowed one of these for a day and was my dream lens for years. However I was never able to buy one because they cost too much but now they are a fraction of the price. I usually tell people no matter what style of photography they shoot they need to just go out and get a fast 50mm to start because these lenses are so useful and if you can run manual they are a bargain.
When shooting manual focus with large apertures like this it can be hard to get your subject in focus. If you are shooting it on a digital camera I would check Ebay to see if your camera can take a split focus screen which makes focusing a lot easier.


Did this review help?
My hopes are to take the time to continue developing this website with more test photo based reviews. If you are ever interested in purchasing this lens or other photography equipment please do so through these links here in this review. I always check Adorama and Ebay for good deals. This helps support my family and allows me to take more time for the site. The best part is this site is free for you and I link good deals I find!

Sometimes these links will actually give you better deals then typical retail prices! I personally buy from the links I have listed whether looking for new gear or fun old stuff. I can personally attest to their good & safe service from years of experience. Thanks again to you, our readers, for supporting us! -Todd