Test: F 50 1.4 vs M 50 1.7 (with photos)


wazzupku

New Member
Apr 24, 2010
218
0
0
#1
Hi, just got a F 50 1.4, so I took it out to test the sharpness of both at wide opened. I think some would like to know the result too.

I tested it under these conditions:
1/ on tripod
2/ EV set to the same (I tried)
3/ shot using selftimer 2s
4/ WB is the same, and not using AWB
5/ without any filter and software adjustment sharpness/color
6/ Camera is Kx

Here is the result
F 50 1.4 @ 1.4


F 50 1.4 @ 1.8


M50 1.7 @ 1.7
 

wazzupku

New Member
Apr 24, 2010
218
0
0
#2
crop F50 1.4 @ 1.4


crop F50 1.4 @ 1.8


crop M 50 1.7 @ 1.7



So, my personal conclusion is that, M 50 1.7 is much sharper at wide opened and warmer color. I will do more test with smaller aperture and post the photos here.

P/S: F 50 1.4 looks like it is out focus. So I change to MF and tried again, the result is still the same.
 

detritus

Senior Member
Sep 12, 2009
2,922
3
0
shootingbugs.blogspot.com
#3
what's your ISO level?

if your objective is to check for optimum sharpness, might be better to use base ISO? i.e. ISO200?

there seems to be some noise in your pic so i'm not sure if u're doing your lens justice? :think:
 

snapnut

New Member
Oct 1, 2004
580
0
0
#4
I have F 50 1.4, M 50 1.7, A 50 1.7.

I have not really test them... but I do not think the F 50 1.4 is that bad.
I did get some of my sharpest images with A 50 1.7 though.

Sharpness do vary among copies.
 

poseur

Senior Member
Jul 27, 2009
1,030
14
38
#5
interesting, i know the FA50 f1.4 is soft but i dont think it is that soft.
I also have both the FA50 and M 50. maybe I do a simliar "test" and see whats the results.
 

Gengh

New Member
May 6, 2007
1,984
0
0
Florida
#6
P/S: F 50 1.4 looks like it is out focus. So I change to MF and tried again, the result is still the same.
Maybe you should do a separate focusing test on the F50 using focusing chart or batteries, just to be sure? Find it quite hard to believe that the lens can be this poor.

This may be a silly question, but when you used MF, did you rely just on your eye, the focus confirmation, or live view with magnification?
 

wazzupku

New Member
Apr 24, 2010
218
0
0
#7
what's your ISO level?

if your objective is to check for optimum sharpness, might be better to use base ISO? i.e. ISO200?

there seems to be some noise in your pic so i'm not sure if u're doing your lens justice? :think:
Hi, ISO is at 400. The noise came is because I cropped it at 100%. But I think you are absolutely right. To check sharpness, I need to set ISO at 100 or 200. But this is just a comparison between 2 lenses, so I thought it doesn't matter as long as the test condition is the same when testing both.

I have F 50 1.4, M 50 1.7, A 50 1.7.

I have not really test them... but I do not think the F 50 1.4 is that bad.
I did get some of my sharpest images with A 50 1.7 though.

Sharpness do vary among copies.
Hi. Could you kindly post us some photos. I would love to see them and also to see if it is only my lens or it is for all.

interesting, i know the FA50 f1.4 is soft but i dont think it is that soft.
I also have both the FA50 and M 50. maybe I do a simliar "test" and see whats the results.
Hi, I would love to see them, thank you.

Maybe you should do a separate focusing test on the F50 using focusing chart or batteries, just to be sure? Find it quite hard to believe that the lens can be this poor.

This may be a silly question, but when you used MF, did you rely just on your eye, the focus confirmation, or live view with magnification?
Hi. With M 50 1.7, I only use my eye to judge. With F 50 1.4, I use 2 method: my eye and catch in focus (which I think it is the same as if I use AF). But both results are the same.

To all, this is F 50 1.4, not FA 50 1.4. F 50 1.4 is the older version, with the noisy motor when auto focus. Just FIY =)
 

Last edited:

pinholecam

Moderator
Staff member
Jul 23, 2007
10,932
85
48
#8
Definitely something wrong on the F50/1.4 shots. Either there is some sort of movement or the lens is not focused correctly.
Choose a better test subject. You are testing on some sort of fan or dehumidifier thingy, which does vibrate with the spinning fan/motor/etc.
Try not to check sharpness through the plastic panel as well, since it distorts and smudges the details as well (not to mention that it can possibly trick AF to focus on the plastic panel rather than the indicator panel inside.

I have tested all the M series 50mm and all the A series 50mm. None are like the test shots you have. :)

Use a deep hood as well to give better contrast.
 

detritus

Senior Member
Sep 12, 2009
2,922
3
0
shootingbugs.blogspot.com
#9
Hi, ISO is at 400. The noise came is because I cropped it at 100%. But I think you are absolutely right. To check sharpness, I need to set ISO at 100 or 200. But this is just a comparison between 2 lenses, so I thought it doesn't matter as long as the test condition is the same when testing both.
in the interest of an objective test, everything matters :) and because you are also taking pictures of the LED display, you are also testing the lens's capabilities to handle high-contrast situation. that's why the test is not limited to "sharpness" per se and imo, is not very conclusive.

Hi. With M 50 1.7, I only use my eye to judge. With F 50 1.4, I use 2 method: my eye and catch in focus (which I think it is the same as if I use AF). But both results are the same.

To all, this is F 50 1.4, not FA 50 1.4. F 50 1.4 is the older version, with the noisy motor when auto focus. Just FIY =)
imo, u could have used MF for both lenses to take the randomness out of the equation, since 1 is an MF and one is AF.

i MF a lot and i find catch in focus and focus confirmation too generous sometimes. best is eye-ball in LV actually. u can swich to LV, magnify by pressing the "info" button to zoom in, and slowly MF until the subject is in sharp focus.

FYI, both the F and the FA are the rather noisy screw drive type of AF :) so no difference strictly speaking.
 

wazzupku

New Member
Apr 24, 2010
218
0
0
#10
Definitely something wrong on the F50/1.4 shots. Either there is some sort of movement or the lens is not focused correctly.
Choose a better test subject. You are testing on some sort of fan or dehumidifier thingy, which does vibrate with the spinning fan/motor/etc.
Try not to check sharpness through the plastic panel as well, since it distorts and smudges the details as well (not to mention that it can possibly trick AF to focus on the plastic panel rather than the indicator panel inside.

I have tested all the M series 50mm and all the A series 50mm. None are like the test shots you have. :)

Use a deep hood as well to give better contrast.
Very value advice! I will re-test it again!

in the interest of an objective test, everything matters :) and because you are also taking pictures of the LED display, you are also testing the lens's capabilities to handle high-contrast situation. that's why the test is not limited to "sharpness" per se and imo, is not very conclusive.



imo, u could have used MF for both lenses to take the randomness out of the equation, since 1 is an MF and one is AF.

i MF a lot and i find catch in focus and focus confirmation too generous sometimes. best is eye-ball in LV actually. u can swich to LV, magnify by pressing the "info" button to zoom in, and slowly MF until the subject is in sharp focus.

FYI, both the F and the FA are the rather noisy screw drive type of AF :) so no difference strictly speaking.
Very informative! I have never tried any lens than the lens I owe (I don't really go around and ask "May I test your lenses" haha). So this is very nice to know F and FA don't different much, beside the years they were born.

I also use the LV and Info button for MF when tested this (and also when I used the extension tube to be a "wannabe macro photographer" hehe)
 

wazzupku

New Member
Apr 24, 2010
218
0
0
#12
macro is fun :) but nothing beats using a 1:1 macro lens when shooting small stuff.

buy buy buy ;)
hahaha, stop poisoning me! Anyway, I have my eye on either Tamron 90 macro or Pentax 35 macro. Any recommendation?
 

detritus

Senior Member
Sep 12, 2009
2,922
3
0
shootingbugs.blogspot.com
#13
hahaha, stop poisoning me! Anyway, I have my eye on either Tamron 90 macro or Pentax 35 macro. Any recommendation?
if u have the budget, the D-FA 100mm WR ;)

if u have no budget and the sky's the limits, there are options that can be discussed as well :think::devil:
 

May 7, 2010
1,028
0
0
#14
inspired by TS, i did a test on my M50/1.7 as well as a recently-acquired Chinon 50/1.4
focusing was done with LV, on the blue labeling of the cough syrup (in russian)


here goes



100%






100%
 

Last edited:
May 7, 2010
1,028
0
0
#17


100%







100%





From this test, i found out that my kx's stop down metering tend to over-expose a little when the lens is wide open, such as the sample of chinon@1.4.
Nonetheless, i leave the results to you guys to determine.
 

wazzupku

New Member
Apr 24, 2010
218
0
0
#18
Thank you evolutioner! After seeing your post, my point stay the same that M 50 1.7 is much sharper than F 50 1.4. Even tho they getting very close @ 2.8 (M 50 1.7 is still sharper at this aperture tho).

However, I took this F 50 1.4 out during lunch time and it produces such beautiful shots of portrait I could ever shot before! Very nice rounded and clear bokeh; with soft and a bit creamy skin tone of the model. I starting to like it! Girls will like it with my white K-x too! lmao
 

May 7, 2010
1,028
0
0
#19
do note that my 50mm 1.4 is not a pentax, it's merely a chinon
 

poseur

Senior Member
Jul 27, 2009
1,030
14
38
#20
Here is my non scientific testing. mounted on my tripod

1 FA50 f1.4 autofocus)


2 FA50 f1.8 (Autofocus)


3 FA50 f2.8 (autofocus)


4 M50 F1.7 (catch in focus)


5 M50 F2.8 (catch in focus)


I do agree FA50 at wide open compare to M50 is a little soft. But stop down almost all are equal.
 

Top Bottom