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Strange thing

BP
Bob Pdml
Mon, Sep 5, 2022 2:12 PM

Well, two strange things really.

First is an on-topic message from me.

Second is an oddity with a Pentax-M 120mm f2.8 lens that I have.

If anyone here has one of these, could you please compare the back of it with your other M lenses?

I have been doing some informal ‘shoot outs’ with my Pentax-M lenses and my Leica lenses, and will put them online if anyone is interested. Anyway, I have been using my Leica M10 monochrome body for all the shots, and a Novoflex adapter for the Pentax lenses, without any problems.

Except that the 120mm lens doesn’t fit the adapter.

On closer inspection, the bit at the back (sorry for the technical jargon) of the 120mm lens where the aperture levers are is significantly different from the other lenses. The photos at this link show you. The 120mm is on the left; the other lens is a 135mm, which is about the same size.

(A link to some pictures should go here, but the server keeps rejecting my emails with links. I’ll try to find another way of showing the pictures).

On the 135mm and other lenses there are some concentric grooves at the back, and it is stepped down. The 120mm is plain, and doesn’t have the step.

On the adapter there is a flange which goes down into the dropped part of the step when you put a lens on, and of course it can’t do this on the plain back end of the 120mm, so the adapter won’t go on the lens.

The lens fits my Pentax MX fine, as well as a number of other MXes I’ve been evaluating with a view to buying a new one. As far as I know it doesn’t affect anything when shooting. However, I need to test this lens specifically as any problems it causes may have become mixed up with problems which have caused me to reject other cameras.

It’s possible that someone has had the lens altered for some reason, although it is otherwise mint-, but it looks almost like a KF mount.

Anybody else have one like this?

Thanks,
Bob

Well, two strange things really. First is an on-topic message from me. Second is an oddity with a Pentax-M 120mm f2.8 lens that I have. If anyone here has one of these, could you please compare the back of it with your other M lenses? I have been doing some informal ‘shoot outs’ with my Pentax-M lenses and my Leica lenses, and will put them online if anyone is interested. Anyway, I have been using my Leica M10 monochrome body for all the shots, and a Novoflex adapter for the Pentax lenses, without any problems. Except that the 120mm lens doesn’t fit the adapter. On closer inspection, the bit at the back (sorry for the technical jargon) of the 120mm lens where the aperture levers are is significantly different from the other lenses. The photos at this link show you. The 120mm is on the left; the other lens is a 135mm, which is about the same size. (A link to some pictures should go here, but the server keeps rejecting my emails with links. I’ll try to find another way of showing the pictures). On the 135mm and other lenses there are some concentric grooves at the back, and it is stepped down. The 120mm is plain, and doesn’t have the step. On the adapter there is a flange which goes down into the dropped part of the step when you put a lens on, and of course it can’t do this on the plain back end of the 120mm, so the adapter won’t go on the lens. The lens fits my Pentax MX fine, as well as a number of other MXes I’ve been evaluating with a view to buying a new one. As far as I know it doesn’t affect anything when shooting. However, I need to test this lens specifically as any problems it causes may have become mixed up with problems which have caused me to reject other cameras. It’s possible that someone has had the lens altered for some reason, although it is otherwise mint-, but it looks almost like a KF mount. Anybody else have one like this? Thanks, Bob
GD
Godfrey DiGiorgi
Tue, Sep 6, 2022 3:35 PM

Hi Bob!

Hmm. I'd seen some odd-ball Pentax lens mount stuff over the days when I was mucking with a bunch of Pentax -M and -A lenses and adapters. Never had a 120mm, I'd be interested to see what the rear mounting flange looks like. I know a couple of Pentax lenses had to have the diaphragm control lever modified to fit one or another lens mount adapter out of the bunch that I had…

If the server kills your email if you embed a link, drop a line to my personal email. :)

G

Godfrey DiGiorgi - godfreydigiorgi@me.com

On Sep 5, 2022, at 7:12 AM, Bob Pdml PDMLBW@hotmail.com wrote:

Well, two strange things really.

First is an on-topic message from me.

Second is an oddity with a Pentax-M 120mm f2.8 lens that I have.

If anyone here has one of these, could you please compare the back of it with your other M lenses?

I have been doing some informal ‘shoot outs’ with my Pentax-M lenses and my Leica lenses, and will put them online if anyone is interested. Anyway, I have been using my Leica M10 monochrome body for all the shots, and a Novoflex adapter for the Pentax lenses, without any problems.

Except that the 120mm lens doesn’t fit the adapter.

On closer inspection, the bit at the back (sorry for the technical jargon) of the 120mm lens where the aperture levers are is significantly different from the other lenses. The photos at this link show you. The 120mm is on the left; the other lens is a 135mm, which is about the same size.

(A link to some pictures should go here, but the server keeps rejecting my emails with links. I’ll try to find another way of showing the pictures).

On the 135mm and other lenses there are some concentric grooves at the back, and it is stepped down. The 120mm is plain, and doesn’t have the step.

On the adapter there is a flange which goes down into the dropped part of the step when you put a lens on, and of course it can’t do this on the plain back end of the 120mm, so the adapter won’t go on the lens.

The lens fits my Pentax MX fine, as well as a number of other MXes I’ve been evaluating with a view to buying a new one. As far as I know it doesn’t affect anything when shooting. However, I need to test this lens specifically as any problems it causes may have become mixed up with problems which have caused me to reject other cameras.

It’s possible that someone has had the lens altered for some reason, although it is otherwise mint-, but it looks almost like a KF mount.

Anybody else have one like this?

Thanks,
Bob

Hi Bob! Hmm. I'd seen some odd-ball Pentax lens mount stuff over the days when I was mucking with a bunch of Pentax -M and -A lenses and adapters. Never had a 120mm, I'd be interested to see what the rear mounting flange looks like. I know a couple of Pentax lenses had to have the diaphragm control lever modified to fit one or another lens mount adapter out of the bunch that I had… If the server kills your email if you embed a link, drop a line to my personal email. :) G — Godfrey DiGiorgi - godfreydigiorgi@me.com > On Sep 5, 2022, at 7:12 AM, Bob Pdml <PDMLBW@hotmail.com> wrote: > > Well, two strange things really. > > First is an on-topic message from me. > > Second is an oddity with a Pentax-M 120mm f2.8 lens that I have. > > If anyone here has one of these, could you please compare the back of it with your other M lenses? > > I have been doing some informal ‘shoot outs’ with my Pentax-M lenses and my Leica lenses, and will put them online if anyone is interested. Anyway, I have been using my Leica M10 monochrome body for all the shots, and a Novoflex adapter for the Pentax lenses, without any problems. > > Except that the 120mm lens doesn’t fit the adapter. > > On closer inspection, the bit at the back (sorry for the technical jargon) of the 120mm lens where the aperture levers are is significantly different from the other lenses. The photos at this link show you. The 120mm is on the left; the other lens is a 135mm, which is about the same size. > > (A link to some pictures should go here, but the server keeps rejecting my emails with links. I’ll try to find another way of showing the pictures). > > On the 135mm and other lenses there are some concentric grooves at the back, and it is stepped down. The 120mm is plain, and doesn’t have the step. > > On the adapter there is a flange which goes down into the dropped part of the step when you put a lens on, and of course it can’t do this on the plain back end of the 120mm, so the adapter won’t go on the lens. > > The lens fits my Pentax MX fine, as well as a number of other MXes I’ve been evaluating with a view to buying a new one. As far as I know it doesn’t affect anything when shooting. However, I need to test this lens specifically as any problems it causes may have become mixed up with problems which have caused me to reject other cameras. > > It’s possible that someone has had the lens altered for some reason, although it is otherwise mint-, but it looks almost like a KF mount. > > Anybody else have one like this? > > Thanks, > Bob
BP
Bob Pdml
Tue, Sep 6, 2022 4:22 PM

Hi Godfrey,

I hope this gets through to PDML.

I’ll send you a picture separately, but I found some photos online of other examples of the M 120/2.8 and they all have the same rear end as mine, so it must be the way it was designed, and the Novoflex adapter hasn’t taken it into account. The global market for people for people wanting to put this particular lens model on a Leica is probably in the neighbourhood of 1, so I’m not surprised…

B

On 6 Sep 2022, at 16:35, Godfrey DiGiorgi godfreydigiorgi@me.com wrote:

Hi Bob!

Hmm. I'd seen some odd-ball Pentax lens mount stuff over the days when I was mucking with a bunch of Pentax -M and -A lenses and adapters. Never had a 120mm, I'd be interested to see what the rear mounting flange looks like. I know a couple of Pentax lenses had to have the diaphragm control lever modified to fit one or another lens mount adapter out of the bunch that I had…

If the server kills your email if you embed a link, drop a line to my personal email. :)

G

Godfrey DiGiorgi - godfreydigiorgi@me.com

Hi Godfrey, I hope this gets through to PDML. I’ll send you a picture separately, but I found some photos online of other examples of the M 120/2.8 and they all have the same rear end as mine, so it must be the way it was designed, and the Novoflex adapter hasn’t taken it into account. The global market for people for people wanting to put this particular lens model on a Leica is probably in the neighbourhood of 1, so I’m not surprised… B > On 6 Sep 2022, at 16:35, Godfrey DiGiorgi <godfreydigiorgi@me.com> wrote: > > Hi Bob! > > Hmm. I'd seen some odd-ball Pentax lens mount stuff over the days when I was mucking with a bunch of Pentax -M and -A lenses and adapters. Never had a 120mm, I'd be interested to see what the rear mounting flange looks like. I know a couple of Pentax lenses had to have the diaphragm control lever modified to fit one or another lens mount adapter out of the bunch that I had… > > If the server kills your email if you embed a link, drop a line to my personal email. :) > > G > — > Godfrey DiGiorgi - godfreydigiorgi@me.com
JS
John Sessoms
Wed, Sep 7, 2022 9:38 PM

I vaguely remember there was a problem either with Ricoh cameras or
Ricoh lenses back in film days. They used the K-mount bayonet, but there
was something they did different and either Ricoh lenses would get stuck
if you mounted them on a Pentax camera or Pentax lenses would get stuck
on Ricoh cameras.

I wish I remembered more specifically what the problem was, and I don't
know if this relates to Bob's problem, but I hope it might somehow help.

On 9/6/2022 11:35 AM, Godfrey DiGiorgi wrote:

Hi Bob!

Hmm. I'd seen some odd-ball Pentax lens mount stuff over the days when I was mucking with a bunch of Pentax -M and -A lenses and adapters. Never had a 120mm, I'd be interested to see what the rear mounting flange looks like. I know a couple of Pentax lenses had to have the diaphragm control lever modified to fit one or another lens mount adapter out of the bunch that I had…

If the server kills your email if you embed a link, drop a line to my personal email. :)

G

Godfrey DiGiorgi - godfreydigiorgi@me.com

On Sep 5, 2022, at 7:12 AM, Bob Pdml PDMLBW@hotmail.com wrote:

Well, two strange things really.

First is an on-topic message from me.

Second is an oddity with a Pentax-M 120mm f2.8 lens that I have.

If anyone here has one of these, could you please compare the back of it with your other M lenses?

I have been doing some informal ‘shoot outs’ with my Pentax-M lenses and my Leica lenses, and will put them online if anyone is interested. Anyway, I have been using my Leica M10 monochrome body for all the shots, and a Novoflex adapter for the Pentax lenses, without any problems.

Except that the 120mm lens doesn’t fit the adapter.

On closer inspection, the bit at the back (sorry for the technical jargon) of the 120mm lens where the aperture levers are is significantly different from the other lenses. The photos at this link show you. The 120mm is on the left; the other lens is a 135mm, which is about the same size.

(A link to some pictures should go here, but the server keeps rejecting my emails with links. I’ll try to find another way of showing the pictures).

On the 135mm and other lenses there are some concentric grooves at the back, and it is stepped down. The 120mm is plain, and doesn’t have the step.

On the adapter there is a flange which goes down into the dropped part of the step when you put a lens on, and of course it can’t do this on the plain back end of the 120mm, so the adapter won’t go on the lens.

The lens fits my Pentax MX fine, as well as a number of other MXes I’ve been evaluating with a view to buying a new one. As far as I know it doesn’t affect anything when shooting. However, I need to test this lens specifically as any problems it causes may have become mixed up with problems which have caused me to reject other cameras.

It’s possible that someone has had the lens altered for some reason, although it is otherwise mint-, but it looks almost like a KF mount.

Anybody else have one like this?

Thanks,
Bob

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I vaguely remember there was a problem either with Ricoh cameras or Ricoh lenses back in film days. They used the K-mount bayonet, but there was something they did different and either Ricoh lenses would get stuck if you mounted them on a Pentax camera or Pentax lenses would get stuck on Ricoh cameras. I wish I remembered more specifically what the problem was, and I don't know if this relates to Bob's problem, but I hope it might somehow help. On 9/6/2022 11:35 AM, Godfrey DiGiorgi wrote: > Hi Bob! > > Hmm. I'd seen some odd-ball Pentax lens mount stuff over the days when I was mucking with a bunch of Pentax -M and -A lenses and adapters. Never had a 120mm, I'd be interested to see what the rear mounting flange looks like. I know a couple of Pentax lenses had to have the diaphragm control lever modified to fit one or another lens mount adapter out of the bunch that I had… > > If the server kills your email if you embed a link, drop a line to my personal email. :) > > G > — > Godfrey DiGiorgi - godfreydigiorgi@me.com > > >> On Sep 5, 2022, at 7:12 AM, Bob Pdml <PDMLBW@hotmail.com> wrote: >> >> Well, two strange things really. >> >> First is an on-topic message from me. >> >> Second is an oddity with a Pentax-M 120mm f2.8 lens that I have. >> >> If anyone here has one of these, could you please compare the back of it with your other M lenses? >> >> I have been doing some informal ‘shoot outs’ with my Pentax-M lenses and my Leica lenses, and will put them online if anyone is interested. Anyway, I have been using my Leica M10 monochrome body for all the shots, and a Novoflex adapter for the Pentax lenses, without any problems. >> >> Except that the 120mm lens doesn’t fit the adapter. >> >> On closer inspection, the bit at the back (sorry for the technical jargon) of the 120mm lens where the aperture levers are is significantly different from the other lenses. The photos at this link show you. The 120mm is on the left; the other lens is a 135mm, which is about the same size. >> >> (A link to some pictures should go here, but the server keeps rejecting my emails with links. I’ll try to find another way of showing the pictures). >> >> On the 135mm and other lenses there are some concentric grooves at the back, and it is stepped down. The 120mm is plain, and doesn’t have the step. >> >> On the adapter there is a flange which goes down into the dropped part of the step when you put a lens on, and of course it can’t do this on the plain back end of the 120mm, so the adapter won’t go on the lens. >> >> The lens fits my Pentax MX fine, as well as a number of other MXes I’ve been evaluating with a view to buying a new one. As far as I know it doesn’t affect anything when shooting. However, I need to test this lens specifically as any problems it causes may have become mixed up with problems which have caused me to reject other cameras. >> >> It’s possible that someone has had the lens altered for some reason, although it is otherwise mint-, but it looks almost like a KF mount. >> >> Anybody else have one like this? >> >> Thanks, >> Bob > -- > %(real_name)s Pentax-Discuss Mail List > To unsubscribe send an email to pdml-leave@pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- Vivere in aeternum aut mori conatur -- This email has been checked for viruses by AVG antivirus software. www.avg.com
LC
Larry Colen
Wed, Sep 7, 2022 9:50 PM

On Sep 7, 2022, at 2:38 PM, John Sessoms jsessoms002@nc.rr.com wrote:

I vaguely remember there was a problem either with Ricoh cameras or Ricoh lenses back in film days. They used the K-mount bayonet, but there was something they did different and either Ricoh lenses would get stuck if you mounted them on a Pentax camera or Pentax lenses would get stuck on Ricoh cameras.

I wish I remembered more specifically what the problem was, and I don't know if this relates to Bob's problem, but I hope it might somehow help.

There was a pin on Ricoh lenses that would catch on something on a Pentax body and you wouldn’t be able to take the lens off the body.

On 9/6/2022 11:35 AM, Godfrey DiGiorgi wrote:

Hi Bob!
Hmm. I'd seen some odd-ball Pentax lens mount stuff over the days when I was mucking with a bunch of Pentax -M and -A lenses and adapters. Never had a 120mm, I'd be interested to see what the rear mounting flange looks like. I know a couple of Pentax lenses had to have the diaphragm control lever modified to fit one or another lens mount adapter out of the bunch that I had…
If the server kills your email if you embed a link, drop a line to my personal email. :)
G

Godfrey DiGiorgi - godfreydigiorgi@me.com

On Sep 5, 2022, at 7:12 AM, Bob Pdml PDMLBW@hotmail.com wrote:

Well, two strange things really.

First is an on-topic message from me.

Second is an oddity with a Pentax-M 120mm f2.8 lens that I have.

If anyone here has one of these, could you please compare the back of it with your other M lenses?

I have been doing some informal ‘shoot outs’ with my Pentax-M lenses and my Leica lenses, and will put them online if anyone is interested. Anyway, I have been using my Leica M10 monochrome body for all the shots, and a Novoflex adapter for the Pentax lenses, without any problems.

Except that the 120mm lens doesn’t fit the adapter.

On closer inspection, the bit at the back (sorry for the technical jargon) of the 120mm lens where the aperture levers are is significantly different from the other lenses. The photos at this link show you. The 120mm is on the left; the other lens is a 135mm, which is about the same size.

(A link to some pictures should go here, but the server keeps rejecting my emails with links. I’ll try to find another way of showing the pictures).

On the 135mm and other lenses there are some concentric grooves at the back, and it is stepped down. The 120mm is plain, and doesn’t have the step.

On the adapter there is a flange which goes down into the dropped part of the step when you put a lens on, and of course it can’t do this on the plain back end of the 120mm, so the adapter won’t go on the lens.

The lens fits my Pentax MX fine, as well as a number of other MXes I’ve been evaluating with a view to buying a new one. As far as I know it doesn’t affect anything when shooting. However, I need to test this lens specifically as any problems it causes may have become mixed up with problems which have caused me to reject other cameras.

It’s possible that someone has had the lens altered for some reason, although it is otherwise mint-, but it looks almost like a KF mount.

Anybody else have one like this?

Thanks,
Bob

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Larry Colen
lrc@red4est.com.  sent from ret4est

> On Sep 7, 2022, at 2:38 PM, John Sessoms <jsessoms002@nc.rr.com> wrote: > > I vaguely remember there was a problem either with Ricoh cameras or Ricoh lenses back in film days. They used the K-mount bayonet, but there was something they did different and either Ricoh lenses would get stuck if you mounted them on a Pentax camera or Pentax lenses would get stuck on Ricoh cameras. > > I wish I remembered more specifically what the problem was, and I don't know if this relates to Bob's problem, but I hope it might somehow help. There was a pin on Ricoh lenses that would catch on something on a Pentax body and you wouldn’t be able to take the lens off the body. > > > On 9/6/2022 11:35 AM, Godfrey DiGiorgi wrote: >> Hi Bob! >> Hmm. I'd seen some odd-ball Pentax lens mount stuff over the days when I was mucking with a bunch of Pentax -M and -A lenses and adapters. Never had a 120mm, I'd be interested to see what the rear mounting flange looks like. I know a couple of Pentax lenses had to have the diaphragm control lever modified to fit one or another lens mount adapter out of the bunch that I had… >> If the server kills your email if you embed a link, drop a line to my personal email. :) >> G >> — >> Godfrey DiGiorgi - godfreydigiorgi@me.com >>> On Sep 5, 2022, at 7:12 AM, Bob Pdml <PDMLBW@hotmail.com> wrote: >>> >>> Well, two strange things really. >>> >>> First is an on-topic message from me. >>> >>> Second is an oddity with a Pentax-M 120mm f2.8 lens that I have. >>> >>> If anyone here has one of these, could you please compare the back of it with your other M lenses? >>> >>> I have been doing some informal ‘shoot outs’ with my Pentax-M lenses and my Leica lenses, and will put them online if anyone is interested. Anyway, I have been using my Leica M10 monochrome body for all the shots, and a Novoflex adapter for the Pentax lenses, without any problems. >>> >>> Except that the 120mm lens doesn’t fit the adapter. >>> >>> On closer inspection, the bit at the back (sorry for the technical jargon) of the 120mm lens where the aperture levers are is significantly different from the other lenses. The photos at this link show you. The 120mm is on the left; the other lens is a 135mm, which is about the same size. >>> >>> (A link to some pictures should go here, but the server keeps rejecting my emails with links. I’ll try to find another way of showing the pictures). >>> >>> On the 135mm and other lenses there are some concentric grooves at the back, and it is stepped down. The 120mm is plain, and doesn’t have the step. >>> >>> On the adapter there is a flange which goes down into the dropped part of the step when you put a lens on, and of course it can’t do this on the plain back end of the 120mm, so the adapter won’t go on the lens. >>> >>> The lens fits my Pentax MX fine, as well as a number of other MXes I’ve been evaluating with a view to buying a new one. As far as I know it doesn’t affect anything when shooting. However, I need to test this lens specifically as any problems it causes may have become mixed up with problems which have caused me to reject other cameras. >>> >>> It’s possible that someone has had the lens altered for some reason, although it is otherwise mint-, but it looks almost like a KF mount. >>> >>> Anybody else have one like this? >>> >>> Thanks, >>> Bob >> -- >> %(real_name)s Pentax-Discuss Mail List >> To unsubscribe send an email to pdml-leave@pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. > > -- > Vivere in aeternum aut mori conatur > > -- > This email has been checked for viruses by AVG antivirus software. > www.avg.com > -- > %(real_name)s Pentax-Discuss Mail List > To unsubscribe send an email to pdml-leave@pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. > -- Larry Colen lrc@red4est.com. sent from ret4est