What is the purpose of the 15mm limited?

**ThorSanchez** · 02-17-2021, 05:34 AM - **1 Like**

Originally posted by photoptimist

LOL!

Then avert your eyes around the video world with it's 1/2", 2/3", and 1" sensors. Worse than being non-metric, those standard dimensions are defined by the diameter of the vacuum tube that would be required to house the vidicon/plumbicon/saticon video circuits!

P.S. I once flummoxed a fellow engineer and devoted proponent of the Imperial system by trying to get him to explain the difference between pounds-force and pounds-mass.

Why do they specify smaller sensors as, say, 1/2.3"? Why on earth wouldn't you just say 7.7mm?

deus ursus · 02-17-2021, 06:10 AM

Originally posted by ThorSanchez

Why do they specify smaller sensors as, say, 1/2.3"? Why on earth wouldn't you just say 7.7mm?

And how do you read it? "One two-point-third"?

**ThorSanchez** · 02-17-2021, 06:16 AM - **1 Like**

Originally posted by deus ursus

And how do you read it? "One two-point-third"?

I read it as "one over two point three inches". Which is way more unwieldy than 7.7 mm.

**UncleVanya** · 02-17-2021, 06:45 AM - **2 Likes**

Originally posted by ThorSanchez

Why do they specify smaller sensors as, say, 1/2.3"? Why on earth wouldn't you just say 7.7mm?

Image sensor format - Wikipedia

It is based on how video cameras tubes were named.

**ThorSanchez** · 02-17-2021, 06:51 AM - **3 Likes**

Originally posted by UncleVanya

Image sensor format - Wikipedia

It is based on how video cameras tubes were named.

I say we just refuse to go along with this nonsense, and refer to them by metric diagonal.

Otherwise I'm switching the speedometer in my car to only read in furlongs per fortnight, and I'm going to steadfastly refuse to order coffee in anything but hogsheads.

**Serkevan** · 02-17-2021, 07:27 AM - **2 Likes**

Originally posted by ThorSanchez

I say we just refuse to go along with this nonsense, and refer to them by metric diagonal.

Otherwise I'm switching the speedometer in my car to only read in furlongs per fortnight, and I'm going to steadfastly refuse to order coffee in anything but hogsheads.

My friends and I measure drinks (from beer to stiffs) in Alcoholitres. It works, mostly.

**UncleVanya** · 02-17-2021, 08:29 AM - **1 Like**

Originally posted by ThorSanchez

I say we just refuse to go along with this nonsense, and refer to them by metric diagonal.

Otherwise I'm switching the speedometer in my car to only read in furlongs per fortnight, and I'm going to steadfastly refuse to order coffee in anything but hogsheads.

Absolutely the most sensible thing to do.

dbs · 02-17-2021, 10:13 PM

With the 15 you will capture the hogshead in one frame ....... at least after 2 coffee's

**Rondec** · 02-18-2021, 04:11 AM - **1 Like**

Originally posted by ThorSanchez

I say we just refuse to go along with this nonsense, and refer to them by metric diagonal.

Otherwise I'm switching the speedometer in my car to only read in furlongs per fortnight, and I'm going to steadfastly refuse to order coffee in anything but hogsheads.

Well, when I'm typing, I try to keep the pressure on the keyboard to less than 2 foot pounds of pressure.

photoptimist · 02-18-2021, 06:54 AM

Shall we return to fathoming what a 1.8 barleycorn lens is good for and knot good for?

**Rondec** · 02-18-2021, 08:40 AM - **1 Like**

I have to say that saying I weigh 14 stone sounds much better than saying I weight 180 lbs.

dbs · 02-18-2021, 06:51 PM

Read the reviews and see if that suits you ?

Suits me

**Cerebum** · 02-19-2021, 02:58 AM - **3 Likes**

Originally posted by dbs

Read the reviews and see if that suits you ?

Suits me

If we are still talking about the 15mm, I have done a sic with it this month and it is now a "top 3, keep forever and possibly be buried with it" lens. It is sensational!

dbs · 02-19-2021, 03:31 PM

Originally posted by Cerebum

If we are still talking about the 15mm, I have done a sic with it this month and it is now a "top 3, keep forever and possibly be buried with it" lens. It is sensational!

Yes..

Not yet ...

and Yes...

Bertrand3000 · 02-19-2021, 03:33 PM

Originally posted by Cerebum

If we are still talking about the 15mm, I have done a sic with it this month and it is now a "top 3, keep forever and possibly be buried with it" lens. It is sensational!

Oh my. I'll have to explain that to my wife...

02-18-2021, 06:54 AM	#205
photoptimist Pentaxian Join Date: Jul 2016 Photos: Albums Posts: 5,126	Shall we return to fathoming what a 1.8 barleycorn lens is good for and knot good for? Last edited by photoptimist; 02-18-2021 at 07:38 AM.

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02-17-2021, 05:34 AM - 1 Like	#196
ThorSanchez Site Supporter Join Date: Dec 2012 Photos: Gallery \| Albums Posts: 2,806	Originally posted by photoptimist LOL! Then avert your eyes around the video world with it's 1/2", 2/3", and 1" sensors. Worse than being non-metric, those standard dimensions are defined by the diameter of the vacuum tube that would be required to house the vidicon/plumbicon/saticon video circuits! P.S. I once flummoxed a fellow engineer and devoted proponent of the Imperial system by trying to get him to explain the difference between pounds-force and pounds-mass. Why do they specify smaller sensors as, say, 1/2.3"? Why on earth wouldn't you just say 7.7mm?

02-17-2021, 06:10 AM	#197
deus ursus Pentaxian Join Date: Nov 2012 Location: Stårheim, Norway Posts: 658	Originally posted by ThorSanchez Why do they specify smaller sensors as, say, 1/2.3"? Why on earth wouldn't you just say 7.7mm? And how do you read it? "One two-point-third"?

02-17-2021, 06:16 AM - 1 Like	#198
ThorSanchez Site Supporter Join Date: Dec 2012 Photos: Gallery \| Albums Posts: 2,806	Originally posted by deus ursus And how do you read it? "One two-point-third"? I read it as "one over two point three inches". Which is way more unwieldy than 7.7 mm.

02-17-2021, 06:45 AM - 2 Likes	#199
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,404	Originally posted by ThorSanchez Why do they specify smaller sensors as, say, 1/2.3"? Why on earth wouldn't you just say 7.7mm? Image sensor format - Wikipedia It is based on how video cameras tubes were named.

02-17-2021, 06:51 AM - 3 Likes	#200
ThorSanchez Site Supporter Join Date: Dec 2012 Photos: Gallery \| Albums Posts: 2,806	Originally posted by UncleVanya Image sensor format - Wikipedia It is based on how video cameras tubes were named. I say we just refuse to go along with this nonsense, and refer to them by metric diagonal. Otherwise I'm switching the speedometer in my car to only read in furlongs per fortnight, and I'm going to steadfastly refuse to order coffee in anything but hogsheads.

02-17-2021, 07:27 AM - 2 Likes	#201
Serkevan Site Supporter Join Date: May 2019 Photos: Albums Posts: 5,976	Originally posted by ThorSanchez I say we just refuse to go along with this nonsense, and refer to them by metric diagonal. Otherwise I'm switching the speedometer in my car to only read in furlongs per fortnight, and I'm going to steadfastly refuse to order coffee in anything but hogsheads. My friends and I measure drinks (from beer to stiffs) in Alcoholitres. It works, mostly.

02-17-2021, 08:29 AM - 1 Like	#202
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,404	Originally posted by ThorSanchez I say we just refuse to go along with this nonsense, and refer to them by metric diagonal. Otherwise I'm switching the speedometer in my car to only read in furlongs per fortnight, and I'm going to steadfastly refuse to order coffee in anything but hogsheads. Absolutely the most sensible thing to do.

02-17-2021, 10:13 PM	#203
dbs Pentaxian Join Date: Jun 2010 Location: Clare Valley S A Photos: Albums Posts: 7,563	With the 15 you will capture the hogshead in one frame ....... at least after 2 coffee's

02-18-2021, 04:11 AM - 1 Like	#204
Rondec Loyal Site Supporter Join Date: Mar 2009 Location: Gladys, Virginia Photos: Gallery Posts: 27,653	Originally posted by ThorSanchez I say we just refuse to go along with this nonsense, and refer to them by metric diagonal. Otherwise I'm switching the speedometer in my car to only read in furlongs per fortnight, and I'm going to steadfastly refuse to order coffee in anything but hogsheads. Well, when I'm typing, I try to keep the pressure on the keyboard to less than 2 foot pounds of pressure.

02-18-2021, 08:40 AM - 1 Like	#206
Rondec Loyal Site Supporter Join Date: Mar 2009 Location: Gladys, Virginia Photos: Gallery Posts: 27,653	I have to say that saying I weigh 14 stone sounds much better than saying I weight 180 lbs.

02-18-2021, 06:51 PM	#207
dbs Pentaxian Join Date: Jun 2010 Location: Clare Valley S A Photos: Albums Posts: 7,563	Read the reviews and see if that suits you ? Suits me

02-19-2021, 02:58 AM - 3 Likes	#208
Cerebum Site Supporter Join Date: Oct 2017 Location: Lancaster Photos: Gallery Posts: 3,828 Original Poster	Originally posted by dbs Read the reviews and see if that suits you ? Suits me If we are still talking about the 15mm, I have done a sic with it this month and it is now a "top 3, keep forever and possibly be buried with it" lens. It is sensational!

02-19-2021, 03:31 PM	#209
dbs Pentaxian Join Date: Jun 2010 Location: Clare Valley S A Photos: Albums Posts: 7,563	Originally posted by Cerebum If we are still talking about the 15mm, I have done a sic with it this month and it is now a "top 3, keep forever and possibly be buried with it" lens. It is sensational! Yes.. Not yet ... and Yes...

02-19-2021, 03:33 PM	#210
Bertrand3000 Veteran Member Join Date: Feb 2019 Posts: 2,009	Originally posted by Cerebum If we are still talking about the 15mm, I have done a sic with it this month and it is now a "top 3, keep forever and possibly be buried with it" lens. It is sensational! Oh my. I'll have to explain that to my wife...