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**.a.t.** · 05-10-2022, 10:01 PM

According to the Pentax Forums Lens Review Database and the Pentax K-Mount Page reference site, the SMC Pentax 28mm f/2 has a minimum focus distance of .25m. So when my recently purchased copy arrived I was surprised to see it had a MFD of .3m.

Looking around on the internet I've seen only .3m MFD copies. And my circa 1977 Pentax lenses booklet also lists the MFD at .3m.

Were there differing versions of this lens? Does anyone here own a K 28mm f/2 with a MFD of .25m?

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Last edited by .a.t.; 05-10-2022 at 10:20 PM. Reason: fine print

Jonathan Mac · 05-11-2022, 03:32 AM

Mine is marked down to 0.3m but moves very slightly beyond that. I haven't measured the distance though.

It focuses as close as I would expect a 28mm lens to, although some 28mm lenses are marketed as "macro" when in fact they're "close focus" and focus a little closer than the Pentax. It's not something I'd complain about.

**UncleVanya** · 05-11-2022, 07:20 AM

Originally posted by .a.t.

According to the Pentax Forums Lens Review Database and the Pentax K-Mount Page reference site, the SMC Pentax 28mm f/2 has a minimum focus distance of .25m. So when my recently purchased copy arrived I was surprised to see it had a MFD of .3m.

Looking around on the internet I've seen only .3m MFD copies. And my circa 1977 Pentax lenses booklet also lists the MFD at .3m.

Were there differing versions of this lens? Does anyone here own a K 28mm f/2 with a MFD of .25m?

Attachment 572887

Attachment 572888

The image you posted clearly shows the lens focused beyond the 0.3 mark.

**.a.t.** · 05-11-2022, 09:49 AM

Originally posted by Jonathan Mac

Mine is marked down to 0.3m but moves very slightly beyond that.
. . .

Thanks for checking.

Originally posted by UncleVanya

The image you posted clearly shows the lens focused beyond the 0.3 mark.

That's my own lens with the focus turned as far as it will go. At that setting, I measured MFD to be between 30 to 31cm.

Last edited by .a.t.; 05-14-2022 at 11:30 AM. Reason: revised measurement

**UncleVanya** · 05-11-2022, 11:17 AM - **1 Like**

Originally posted by .a.t.

That's my own lens with the focus turned as far as it will go. At that setting, I measured MFD to be 31cm.

And infinity is set accurately?

**.a.t.** · 05-11-2022, 12:21 PM

Originally posted by UncleVanya

And infinity is set accurately?

Yes. But I had to go double check just to be certain. Thank you for the reminder.

The Pentax K 28mm f/2 is said to be based on the Zeiss Distagon 28mm f/2 :
SMCÂ* PENTAXÂ* 28mm f

And this source shows the Distagon has a MFD of .24m :
https://lens-db.com/carl-zeiss-cy-distagon-t-28mm-f2-ae-1975/

So if the .25m claim for the Pentax version is wrong, it would be an understandable mistake.

**UncleVanya** · 05-11-2022, 07:08 PM

Originally posted by .a.t.

Yes. But I had to go double check just to be certain. Thank you for the reminder.

The Pentax K 28mm f/2 is said to be based on the Zeiss Distagon 28mm f/2 :
SMCÂ* PENTAXÂ* 28mm f

And this source shows the Distagon has a MFD of .24m :
https://lens-db.com/carl-zeiss-cy-distagon-t-28mm-f2-ae-1975/

So if the .25m claim for the Pentax version is wrong, it would be an understandable mistake.

Very interesting.

**dkpentax** · 05-12-2022, 07:58 PM

I have an early one like your picture and also a later one, both have identical focus scales to your picture. I think they just rounded it off for the brochure.

**.a.t.** · 05-12-2022, 09:19 PM

Originally posted by dkpentax

I have an early one like your picture and also a later one, both have identical focus scales to your picture. I think they just rounded it off for the brochure.

Thank you.

Again, has anybody here owned - or even seen - a .25m minimum focus distance copy of the SMC "K" 28mm f/2 lens?

The Pentax Forums Lens Review Database is a treasure and I'd like to help Adam & Ole make sure they have accurate data there.

LennyBloke · 05-13-2022, 01:31 AM

0.3m is the closest marked setting on my copy too!

**.a.t.** · 05-13-2022, 08:48 AM

Originally posted by LennyBloke

0.3m is the closest marked setting on my copy too!

Thank you, LennyBloke.

**Lowell Goudge** · 05-13-2022, 09:00 AM - **1 Like**

Maybe the is a difference between minimum focus distance and minimum working distance.

Minimum focus is to the film plane minimum working is to the front element.

But aside from that minor distinction, does it really matter in reality, and perhaps this is a copy paste error,

**.a.t.** · 05-13-2022, 03:03 PM

Originally posted by Lowell Goudge

. . .

But aside from that minor distinction, does it really matter in reality ...

Yes, tilting at windmills, perhaps?

But it seems to me a database is more useful if it includes complete and accurate information.

pschlute · 05-13-2022, 10:56 PM - **1 Like**

Originally posted by LennyBloke

0.3m is the closest marked setting on my copy too!

Is that on all of them John ?

**gofour3** · 05-14-2022, 09:19 AM

Originally posted by .a.t.

SMC Pentax 28mm f/2 minimum focus distance?

I have the first 1976 version, same as yours, it has 0.3 as well for the MFD.

Phil.

05-10-2022, 10:01 PM	#1
.a.t. Site Supporter Join Date: Mar 2011 Location: yesterday Photos: Gallery Posts: 1,261	SMC Pentax 28mm f/2 minimum focus distance? According to the Pentax Forums Lens Review Database and the Pentax K-Mount Page reference site, the SMC Pentax 28mm f/2 has a minimum focus distance of .25m. So when my recently purchased copy arrived I was surprised to see it had a MFD of .3m. Looking around on the internet I've seen only .3m MFD copies. And my circa 1977 Pentax lenses booklet also lists the MFD at .3m. Were there differing versions of this lens? Does anyone here own a K 28mm f/2 with a MFD of .25m? Last edited by .a.t.; 05-10-2022 at 10:20 PM. Reason: fine print

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05-11-2022, 03:32 AM	#2
Jonathan Mac Pentaxian Join Date: Apr 2009 Location: Madrid, Spain Posts: 10,916	Mine is marked down to 0.3m but moves very slightly beyond that. I haven't measured the distance though. It focuses as close as I would expect a 28mm lens to, although some 28mm lenses are marketed as "macro" when in fact they're "close focus" and focus a little closer than the Pentax. It's not something I'd complain about.

05-11-2022, 07:20 AM	#3
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,476	Originally posted by .a.t. According to the Pentax Forums Lens Review Database and the Pentax K-Mount Page reference site, the SMC Pentax 28mm f/2 has a minimum focus distance of .25m. So when my recently purchased copy arrived I was surprised to see it had a MFD of .3m. Looking around on the internet I've seen only .3m MFD copies. And my circa 1977 Pentax lenses booklet also lists the MFD at .3m. Were there differing versions of this lens? Does anyone here own a K 28mm f/2 with a MFD of .25m? Attachment 572887 Attachment 572888 The image you posted clearly shows the lens focused beyond the 0.3 mark.

05-11-2022, 09:49 AM	#4
.a.t. Site Supporter Join Date: Mar 2011 Location: yesterday Photos: Gallery Posts: 1,261 Original Poster	Originally posted by Jonathan Mac Mine is marked down to 0.3m but moves very slightly beyond that. . . . Thanks for checking. Originally posted by UncleVanya The image you posted clearly shows the lens focused beyond the 0.3 mark. That's my own lens with the focus turned as far as it will go. At that setting, I measured MFD to be between 30 to 31cm. Last edited by .a.t.; 05-14-2022 at 11:30 AM. Reason: revised measurement

05-11-2022, 11:17 AM - 1 Like	#5
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,476	Originally posted by .a.t. That's my own lens with the focus turned as far as it will go. At that setting, I measured MFD to be 31cm. And infinity is set accurately?

05-11-2022, 12:21 PM	#6
.a.t. Site Supporter Join Date: Mar 2011 Location: yesterday Photos: Gallery Posts: 1,261 Original Poster	Originally posted by UncleVanya And infinity is set accurately? Yes. But I had to go double check just to be certain. Thank you for the reminder. The Pentax K 28mm f/2 is said to be based on the Zeiss Distagon 28mm f/2 : SMCÂ* PENTAXÂ* 28mm f And this source shows the Distagon has a MFD of .24m : https://lens-db.com/carl-zeiss-cy-distagon-t-28mm-f2-ae-1975/ So if the .25m claim for the Pentax version is wrong, it would be an understandable mistake.

05-11-2022, 07:08 PM	#7
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,476	Originally posted by .a.t. Yes. But I had to go double check just to be certain. Thank you for the reminder. The Pentax K 28mm f/2 is said to be based on the Zeiss Distagon 28mm f/2 : SMCÂ* PENTAXÂ* 28mm f And this source shows the Distagon has a MFD of .24m : https://lens-db.com/carl-zeiss-cy-distagon-t-28mm-f2-ae-1975/ So if the .25m claim for the Pentax version is wrong, it would be an understandable mistake. Very interesting.

05-12-2022, 07:58 PM	#8
dkpentax Site Supporter Join Date: Jun 2020 Posts: 132	I have an early one like your picture and also a later one, both have identical focus scales to your picture. I think they just rounded it off for the brochure.

05-12-2022, 09:19 PM	#9
.a.t. Site Supporter Join Date: Mar 2011 Location: yesterday Photos: Gallery Posts: 1,261 Original Poster	Originally posted by dkpentax I have an early one like your picture and also a later one, both have identical focus scales to your picture. I think they just rounded it off for the brochure. Thank you. Again, has anybody here owned - or even seen - a .25m minimum focus distance copy of the SMC "K" 28mm f/2 lens? The Pentax Forums Lens Review Database is a treasure and I'd like to help Adam & Ole make sure they have accurate data there.

05-13-2022, 01:31 AM	#10
LennyBloke Pentaxian Join Date: Aug 2008 Location: Worcestershire, UK Photos: Gallery Posts: 678	0.3m is the closest marked setting on my copy too!

05-13-2022, 08:48 AM	#11
.a.t. Site Supporter Join Date: Mar 2011 Location: yesterday Photos: Gallery Posts: 1,261 Original Poster	Originally posted by LennyBloke 0.3m is the closest marked setting on my copy too! Thank you, LennyBloke.

05-13-2022, 09:00 AM - 1 Like	#12
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,892	Maybe the is a difference between minimum focus distance and minimum working distance. Minimum focus is to the film plane minimum working is to the front element. But aside from that minor distinction, does it really matter in reality, and perhaps this is a copy paste error,

05-13-2022, 03:03 PM	#13
.a.t. Site Supporter Join Date: Mar 2011 Location: yesterday Photos: Gallery Posts: 1,261 Original Poster	Originally posted by Lowell Goudge . . . But aside from that minor distinction, does it really matter in reality ... Yes, tilting at windmills, perhaps? But it seems to me a database is more useful if it includes complete and accurate information.

05-13-2022, 10:56 PM - 1 Like	#14
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,223	Originally posted by LennyBloke 0.3m is the closest marked setting on my copy too! Is that on all of them John ?

05-14-2022, 09:19 AM	#15
gofour3 Site Supporter Join Date: Oct 2008 Location: Vancouver, Canada Posts: 8,093	Originally posted by .a.t. SMC Pentax 28mm f/2 minimum focus distance? I have the first 1976 version, same as yours, it has 0.3 as well for the MFD. Phil.