two vintage 28mm but different

babbustaman · 04-22-2021, 11:57 AM

Hi guys,

I've recently bought to vintage lensen. Both are 28mm 3.5. But they are different i sizes.

One is named smc pentax 3.5/28mm

the other smc pentax-m 3.5/28mm

Any of you know the difference in these? It seems that the pentax-m (only taken a few pictures) gives better bokeh, more warmer colors and is not in the need of much light to perform well. The other is alos supersharp, but it seems a bit more demanding to get nice results. a bit colder in the colors and against the sun the flare is not so good (but this however needs to be tested more)

attached pictures of the lenses

Attached Images

View Picture EXIF

View Picture EXIF

**jumbleview** · 04-22-2021, 12:04 PM

The bigger one (without letter "m"") is probably K-lens. SMC Pentax 28mm F3.5 Reviews - K Prime Lenses - Pentax Lens Reviews & Lens Database

**boriscleto** · 04-22-2021, 12:05 PM - **1 Like**

The first is from the K series and the second is from the M series...

Pentax K-Mount Lenses Explained: The differences between various Pentax lens series

SMC Pentax 28mm F3.5 Reviews - K Prime Lenses - Pentax Lens Reviews & Lens Database

SMC Pentax-M 28mm F3.5 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database

The K is 8 elements in 7 groups, the M is 6 elements in 6 groups. The optical formula changed to make the lens smaller.

**Marktax** · 04-22-2021, 12:08 PM

The M in SMC-M stands for "miniature" owing to an era at Asahi Optical Co. (Pentax) when they undertook to make cameras and lenses more compact. All of the lens elements and formulas were redesigned as between SMC's and SMC-M's at the same focal lengths and speeds, making the lenses smaller. Rendering characteristics are thus necessarily different.

**TwoUptons** · 04-22-2021, 12:10 PM - **1 Like**

The general perception is that the M-series lenses may have given up some optical quality in search of compactness, though that is not universal...

Lens coatings changed over the years, and it’s likely the SMC lens has a different formulation than the SMC-M. That could account for some of the color differences.

There’s also issues with sample variation, both when the lenses were made as well as in how they were treated in service... which often results in the majority of differences in otherwise similar lenses.

Both of these lenses are also in the lens database here:

SMC Pentax 28mm F3.5 Reviews - K Prime Lenses - Pentax Lens Reviews & Lens Database

And here:

SMC Pentax-M 28mm F3.5 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database

-Eric

babbustaman · 04-22-2021, 12:24 PM

Thanks for the reply.

Yeah I read the review for the lens without the m before i bought it. The other one I traded. Looking foreward to thest them a bit more.

pschlute · 04-22-2021, 12:35 PM - **1 Like**

Originally posted by babbustaman

Thanks for the reply.

Yeah I read the review for the lens without the m before i bought it. The other one I traded. Looking foreward to thest them a bit more.

The K 28mm 3.5 is widely acknowledged as the 2nd best 28mm of its era. It is sharp and produces great pictures.

Gene D · 04-22-2021, 01:40 PM - **1 Like**

Originally posted by pschlute

The K 28mm 3.5 is widely acknowledged as the 2nd best 28mm of its era. It is sharp and produces great pictures.

I have had the K 28mm 3.5 for about 6 months. Its an amazing lens, the colors and contrasts are great, sharpness really great. Reviews here place it much better than the M. Am using it on my KP. For the price/quality, could not be happier. The one I understand that is supposed to be "the best" per reviews, is the same K series only the f2.0, think they call it the "Hollywood". This sells for probably a factor of 6-8x the price of the 3.5. Just recently having started doing more with these older lenses, I can say that this lens is very easy to focus. The metering and the "green" button use takes some time to get used to and adjust. I do always use a hood and find that setting the right metering takes a bit of work but my results now are really nice. Something about the K series that is just special. Hope you enjoy it!

shyrsio · 04-22-2021, 02:15 PM - **1 Like**

You'll find that the K version gets great praises from the users. I have the M myself and I love it, but it's no K.

pinholecam · 04-22-2021, 08:35 PM - **1 Like**

Originally posted by babbustaman

Hi guys,

I've recently bought to vintage lensen. Both are 28mm 3.5. But they are different i sizes.

One is named smc pentax 3.5/28mm

the other smc pentax-m 3.5/28mm

Any of you know the difference in these? It seems that the pentax-m (only taken a few pictures) gives better bokeh, more warmer colors and is not in the need of much light to perform well. The other is alos supersharp, but it seems a bit more demanding to get nice results. a bit colder in the colors and against the sun the flare is not so good (but this however needs to be tested more)

attached pictures of the lenses

The other is useless junk, I'd buy it from you for $100.

Its the K28/3.5, and its probably the best landscape legacy 28mm for the price (across any brand) - on FF
I find it un-inspired for any other type of shooting that I do though (eg. children, shallow DOF, candids )

K28/3.5

The M28/3.5 is nice and handy, but looses out in end sharpness by a large margin (and more vignetting); again within the FF context.

**pentaxus** · 04-22-2021, 09:33 PM - **1 Like**

I had the K version and it was amazing. It was sharp and didn't have barrel distortion.

babbustaman · 04-23-2021, 12:22 AM

Originally posted by pinholecam

The other is useless junk, I'd buy it from you for $100.

Its the K28/3.5, and its probably the best landscape legacy 28mm for the price (across any brand) - on FF
I find it un-inspired for any other type of shooting that I do though (eg. children, shallow DOF, candids )

K28/3.5

The M28/3.5 is nice and handy, but looses out in end sharpness by a large margin (and more vignetting); again within the FF context.

Awsome sharpness in those pictures man! I thin I will stick to both. I have a feeling both are good in different scenarios.

pinholecam · 04-23-2021, 02:15 AM - **1 Like**

Originally posted by babbustaman

Awsome sharpness in those pictures man! I thin I will stick to both. I have a feeling both are good in different scenarios.

My preference for an all rounder over the M28/3.5 is the K24/2.8.
Somehow better for an all rounder imho.
Better subject separation, very center sharp at f3.5-4.
Faster.
Wider FOV that is really as wide as one need for most natural landscapes.
Also I find that 24mm is the max that can benefit from hyperfocal focusing w/o a need to resort to focus stacking.

K28/3.5 is one of my go to cityscape/landscape lenses, I certainly won't part with mine.

With the K24/2.8

No harm keeping the M28/3.5 since its so cheap.
Just that if I was to keep only one 28mm, then it will be the K28/3.5 and K24/2.8 (as the other lens )

babbustaman · 04-23-2021, 03:54 AM

Originally posted by pinholecam

My preference for an all rounder over the M28/3.5 is the K24/2.8.
Somehow better for an all rounder imho.
Better subject separation, very center sharp at f3.5-4.
Faster.
Wider FOV that is really as wide as one need for most natural landscapes.
Also I find that 24mm is the max that can benefit from hyperfocal focusing w/o a need to resort to focus stacking.

K28/3.5 is one of my go to cityscape/landscape lenses, I certainly won't part with mine.

With the K24/2.8

No harm keeping the M28/3.5 since its so cheap.
Just that if I was to keep only one 28mm, then it will be the K28/3.5 and K24/2.8 (as the other lens )

Thanks for the clarification. I'm keeping both. The little I tested so far I found out that the K seem to demand a bit more light than the m (on the K-7). But it isn't any downside to that. Just something I noticed.

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04-22-2021, 12:04 PM	#2
jumbleview Site Supporter Join Date: May 2012 Location: Concord, CA Posts: 959	The bigger one (without letter "m"") is probably K-lens. SMC Pentax 28mm F3.5 Reviews - K Prime Lenses - Pentax Lens Reviews & Lens Database

04-22-2021, 12:05 PM - 1 Like	#3
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,240	The first is from the K series and the second is from the M series... Pentax K-Mount Lenses Explained: The differences between various Pentax lens series SMC Pentax 28mm F3.5 Reviews - K Prime Lenses - Pentax Lens Reviews & Lens Database SMC Pentax-M 28mm F3.5 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database The K is 8 elements in 7 groups, the M is 6 elements in 6 groups. The optical formula changed to make the lens smaller.

04-22-2021, 12:08 PM	#4
Marktax Site Supporter Join Date: Jun 2013 Location: Washington DC Photos: Albums Posts: 609	The M in SMC-M stands for "miniature" owing to an era at Asahi Optical Co. (Pentax) when they undertook to make cameras and lenses more compact. All of the lens elements and formulas were redesigned as between SMC's and SMC-M's at the same focal lengths and speeds, making the lenses smaller. Rendering characteristics are thus necessarily different.

04-22-2021, 12:10 PM - 1 Like	#5
TwoUptons Loyal Site Supporter Join Date: Nov 2015 Photos: Albums Posts: 3,525	The general perception is that the M-series lenses may have given up some optical quality in search of compactness, though that is not universal... Lens coatings changed over the years, and it’s likely the SMC lens has a different formulation than the SMC-M. That could account for some of the color differences. There’s also issues with sample variation, both when the lenses were made as well as in how they were treated in service... which often results in the majority of differences in otherwise similar lenses. Both of these lenses are also in the lens database here: SMC Pentax 28mm F3.5 Reviews - K Prime Lenses - Pentax Lens Reviews & Lens Database And here: SMC Pentax-M 28mm F3.5 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database -Eric

04-22-2021, 12:24 PM	#6
babbustaman Junior Member Join Date: Feb 2020 Photos: Albums Posts: 38 Original Poster	Thanks for the reply. Yeah I read the review for the lens without the m before i bought it. The other one I traded. Looking foreward to thest them a bit more.

04-22-2021, 12:35 PM - 1 Like	#7
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 6,501	Originally posted by babbustaman Thanks for the reply. Yeah I read the review for the lens without the m before i bought it. The other one I traded. Looking foreward to thest them a bit more. The K 28mm 3.5 is widely acknowledged as the 2nd best 28mm of its era. It is sharp and produces great pictures.

04-22-2021, 01:40 PM - 1 Like	#8
Gene D Forum Member Join Date: Jan 2017 Photos: Gallery \| Albums Posts: 54	Originally posted by pschlute The K 28mm 3.5 is widely acknowledged as the 2nd best 28mm of its era. It is sharp and produces great pictures. I have had the K 28mm 3.5 for about 6 months. Its an amazing lens, the colors and contrasts are great, sharpness really great. Reviews here place it much better than the M. Am using it on my KP. For the price/quality, could not be happier. The one I understand that is supposed to be "the best" per reviews, is the same K series only the f2.0, think they call it the "Hollywood". This sells for probably a factor of 6-8x the price of the 3.5. Just recently having started doing more with these older lenses, I can say that this lens is very easy to focus. The metering and the "green" button use takes some time to get used to and adjust. I do always use a hood and find that setting the right metering takes a bit of work but my results now are really nice. Something about the K series that is just special. Hope you enjoy it!

04-22-2021, 02:15 PM - 1 Like	#9
shyrsio Pentaxian Join Date: Apr 2016 Location: Tirana Posts: 754	You'll find that the K version gets great praises from the users. I have the M myself and I love it, but it's no K.

04-22-2021, 08:35 PM - 1 Like	#10
pinholecam Pentaxian Join Date: Oct 2009 Location: North Photos: Gallery Posts: 4,656	Originally posted by babbustaman Hi guys, I've recently bought to vintage lensen. Both are 28mm 3.5. But they are different i sizes. One is named smc pentax 3.5/28mm the other smc pentax-m 3.5/28mm Any of you know the difference in these? It seems that the pentax-m (only taken a few pictures) gives better bokeh, more warmer colors and is not in the need of much light to perform well. The other is alos supersharp, but it seems a bit more demanding to get nice results. a bit colder in the colors and against the sun the flare is not so good (but this however needs to be tested more) attached pictures of the lenses The other is useless junk, I'd buy it from you for $100. Its the K28/3.5, and its probably the best landscape legacy 28mm for the price (across any brand) - on FF I find it un-inspired for any other type of shooting that I do though (eg. children, shallow DOF, candids ) K28/3.5 The M28/3.5 is nice and handy, but looses out in end sharpness by a large margin (and more vignetting); again within the FF context.

04-22-2021, 09:33 PM - 1 Like	#11
pentaxus Site Supporter Join Date: Jun 2010 Location: Central Coast, CA Posts: 1,235	I had the K version and it was amazing. It was sharp and didn't have barrel distortion.

04-23-2021, 12:22 AM	#12
babbustaman Junior Member Join Date: Feb 2020 Photos: Albums Posts: 38 Original Poster	Originally posted by pinholecam The other is useless junk, I'd buy it from you for $100. Its the K28/3.5, and its probably the best landscape legacy 28mm for the price (across any brand) - on FF I find it un-inspired for any other type of shooting that I do though (eg. children, shallow DOF, candids ) K28/3.5 The M28/3.5 is nice and handy, but looses out in end sharpness by a large margin (and more vignetting); again within the FF context. Awsome sharpness in those pictures man! I thin I will stick to both. I have a feeling both are good in different scenarios.

04-23-2021, 02:15 AM - 1 Like	#13
pinholecam Pentaxian Join Date: Oct 2009 Location: North Photos: Gallery Posts: 4,656	Originally posted by babbustaman Awsome sharpness in those pictures man! I thin I will stick to both. I have a feeling both are good in different scenarios. My preference for an all rounder over the M28/3.5 is the K24/2.8. Somehow better for an all rounder imho. Better subject separation, very center sharp at f3.5-4. Faster. Wider FOV that is really as wide as one need for most natural landscapes. Also I find that 24mm is the max that can benefit from hyperfocal focusing w/o a need to resort to focus stacking. K28/3.5 is one of my go to cityscape/landscape lenses, I certainly won't part with mine. With the K24/2.8 No harm keeping the M28/3.5 since its so cheap. Just that if I was to keep only one 28mm, then it will be the K28/3.5 and K24/2.8 (as the other lens )

04-23-2021, 03:54 AM	#14
babbustaman Junior Member Join Date: Feb 2020 Photos: Albums Posts: 38 Original Poster	Originally posted by pinholecam My preference for an all rounder over the M28/3.5 is the K24/2.8. Somehow better for an all rounder imho. Better subject separation, very center sharp at f3.5-4. Faster. Wider FOV that is really as wide as one need for most natural landscapes. Also I find that 24mm is the max that can benefit from hyperfocal focusing w/o a need to resort to focus stacking. K28/3.5 is one of my go to cityscape/landscape lenses, I certainly won't part with mine. With the K24/2.8 No harm keeping the M28/3.5 since its so cheap. Just that if I was to keep only one 28mm, then it will be the K28/3.5 and K24/2.8 (as the other lens ) Thanks for the clarification. I'm keeping both. The little I tested so far I found out that the K seem to demand a bit more light than the m (on the K-7). But it isn't any downside to that. Just something I noticed.

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