Author Topic: Another great old photo  (Read 648 times)

Online RichardL

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Re: Another great old photo
« Reply #15 on: 01.03. 2023 23:41 »
Those old time cameras had such great clarity and depth of field.

It's amazing how sharp an image can be when the pixel size is that of a silver nitrate molecule. By my calculation, a 4"x5" photo would have about 310M Megapixels (310,000,620,001,240). Maybe there's a photographer (or photography scientist) here who understands it better.

Richard L.

Edit: Maybe that should be stated as "310 Trillion pixels?

Online Joolstacho

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Re: Another great old photo
« Reply #16 on: 02.03. 2023 00:10 »
The original would be shot at least Medium Format - Perhaps Rolleiflex, Mamiya or Hassleblad. But quite likely 5x4 plate camera.
The edge to edge sharpness is remarkable eh? Very good lens!

Yes, film converted to digital size would be enormous, but how big that's actually NEEDED depends on output dimensions and also the file format (compressed or uncompressed).
A standard High-Res image at A4 is 300ppi (pixels per inch).
'Course we have to be careful nowadays, -that photograph could well have been sharpened a touch in Photoshop.

Online RichardL

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Re: Another great old photo
« Reply #17 on: 02.03. 2023 04:38 »
OK, I'll torture this topic until the dead guys in the picture scream.  By my calculation, based on visual acuity of one minute of arc, the highest resolution of a 4"x5" photo held 10" from one's face, and which we could visually process, would be about 3.4 Megapixels. Hey! You! In the back of the room, wake up!

Richard L.

Online Joolstacho

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Re: Another great old photo
« Reply #18 on: 02.03. 2023 05:27 »
Haha Richard, not sure about the visual acuity (bluddy'ell where's my glass!) stuff but... Bear in mind that you have each pixel, but each pixel has to have a 'value'. So, simple black and white (no tones) require minimal data, just Black or White, but Greyscale (like the picture in question) would require 256 levels of grey for each pixel. If it's an RGB file destined for the screen, each pixel needs to have a Red, Green, and Blue value, but for RGB you only need to work at 72ppi anyway, because the pixels on the screen are mostly 72ppi, (any res higher just gets interpolated down to 72ppi). Then again, full colour work for quality commercial printing, like magazines require 300ppi, but each pixel needs to have a colour value assigned based on the '4-colour Process' system, so each pixel needs to have a Cyan, Magenta, Yellow, Black (K), value. (CMYK are the ink colours run on the printing press).

That original photo, when you analyse it, is the work of a very good photographer... Especially later in the darkroom where in the neg processing and the resulting print has been expertly handled, -the tonal range has been very nicely controlled. Just look at the tonal range. Superb. There's so much more to it than just pixel resolution.
It's been shot on the 'ideal light' day... not bright sun, not dark cloud, just a nice thin cloud haze filtering the sun, (look at the soft shadows). There's great tonal range in it.

(Probably way too much information!)

Online CheeserBeezer

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Re: Another great old photo
« Reply #19 on: 02.03. 2023 08:00 »
This is Sevenoaks in Kent. the shop is now an Estate Agents.
Ah, I wondered if 'Sev' referred to Sevenoaks. Is that a location you know Andrew?
No, I was just doing some internet sleuthing.

Online groily

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Re: Another great old photo
« Reply #20 on: 02.03. 2023 09:02 »
A mate in a parallel universe says pic is '1960': 3 x ISDT machines, two 350s and a 500, all short-strokes. Stacks up. Nice bikes, and they go very well, but never been tempted into AMC singles - Beesa or Ariel only on the one-pot front in my life.

Brilliant quality picture. A lot of info out there on Angus Herbert, dealer and ex-racer etc.

Am also told that Norman died as a marque in 1961, but haven't checked yet as I'm not that nippy.
Bill

Offline Greybeard

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Re: Another great old photo
« Reply #21 on: 02.03. 2023 09:35 »
This is Sevenoaks in Kent. the shop is now an Estate Agents.
Ah, I wondered if 'Sev' referred to Sevenoaks. Is that a location you know Andrew?
No, I was just doing some internet sleuthing.
I also ran Streetview but didn't recognise that location 🤔
Greybeard (Neil)
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Offline Greybeard

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Re: Another great old photo
« Reply #22 on: 02.03. 2023 09:37 »
I was hoping my comment would trigger posts about the quality of the photograph 👍
Greybeard (Neil)
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Offline BSA_54A10

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Re: Another great old photo
« Reply #23 on: 02.03. 2023 12:42 »
Those old time cameras had such great clarity and depth of field.

It's amazing how sharp an image can be when the pixel size is that of a silver nitrate molecule. By my calculation, a 4"x5" photo would have about 310M Megapixels (310,000,620,001,240). Maybe there's a photographer (or photography scientist) here who understands it better.

Richard L.

Edit: Maybe that should be stated as "310 Trillion pixels?[/color

How quickly things are forgotten
Film came in ASA ratings which was a measure of the grain size and determined the exposure time
And you could get it from 80 to 400 for standard film or 100 to 600 for slide film
There were more grades availible for professionals but it became very expensive very quickly and processing was even more expensive .
The story was the same with printing paper
B & W was graded with letters and colour was graded with numbers
Depth of field is simply a function of the quality of the lense, aperature size , exposure time & film grain size.
With SLRs you could set the depth of field that you wanted .
The histance of the lense from the film plane set the front  of the focal plan & the apperature set the back of the focal plane
We got very used to fashion photography where the depth of fiels is set very shallow so the model is clear & the back ground is fuzzy.
This was done to make you pay attention to what the model was wearing and also to disguise the location of the photograph

Then there was the stock size
For printing out to the old 6 x 4 or 8 x 5 any film from 8mm to 35 mm was fine ( using the right grade of film )
for larger print you needed a magazine backed camera for stills or a 120 for action.

I used to have a Roliflex 2.5 x 4 and a Leitz 3 x 4.5 and boy was I happy when I got the bellows for the OM2 so I could forget about cutting up sheets of film under safe light and loading magazines .
In the days of no cost digital photography we forget that a roll of good film would  set you back 3 hours wages and processing was about a full days wages which is why magazine backed cameras remianed the norm for newspaper right up untill the 70's.

As for the shot itself, yes probably done with a magazine backed camera, and better than average chance it was a publicity shot for Matchless
Note all of the bikes are parked perfectly parallel so they are all in clear focus
You can just about make out the grins the people are trying to conceal
And if you run them past some older enthusiasts you will probably find they were period racers of some type who were generally used for road testing new bikes & of course publicity photographs .

Now if you really want to play with numbers
Silver Nitrate has an atomic mass of 170g/ mole
Avergardo number is 10 to the 23 atoms  per mole
A roll of 35mm stills film has around 400 mg of recoverable silver

Oh and one grain of silver halide can have a gradient frm one side to the other so 1 grain does not necessarily = 1 pixel
And a pixel is not a fixed size .
Bike Beesa
Trevor

Online RichardL

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Re: Another great old photo
« Reply #24 on: 02.03. 2023 13:33 »
I was being more simplistic (obviously). Looked up size of silver nitrate molecule and used the top of the range. As for acuity, one minute of arc is commonly accepted and is part OF THE technology of the Snell eye chart evaluation of 20/20 vision.

Richard L.

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Re: Another great old photo
« Reply #25 on: 02.03. 2023 13:50 »
Superb one GB. Really nice prial of CS Matchless singles
I checked the word 'prial', wondering if it was a typo;  it's a word I've not seen before 🤔

prial
/ˈprʌɪəl/
noun
(in card games) a set of three cards of the same denomination.


I knew that a pronunciation like “prile” was a contraction of “pair Royal,” but I didn’t know it had a proper spelling.

Offline Greybeard

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Re: Another great old photo
« Reply #26 on: 02.03. 2023 14:11 »
I knew that a pronunciation like “prile” was a contraction of “pair Royal,” but I didn’t know it had a proper spelling.

Well I never!  *smile*
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Online groily

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Re: Another great old photo
« Reply #27 on: 07.03. 2023 07:52 »
And for completeness, the names of the folk in GB's pic, some pretty familiar  . . .

"Matchless dealer Angus Herbert (second from left) outside his agency. Others are Bruce Main-Smith, then Herbert, the shop manager,  AMC's Mike Marriot and Motor Cycling staffman Mike Bashford. The machines are ISDT models, with two 350s sandwiching a 500."
Bill

Offline Swarfcut

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Re: Another great old photo
« Reply #28 on: 07.03. 2023 08:54 »
 Proprietor Herbert also appears to be paying his dues as an AMIMI...An Associate Member of the Institute of the Motor Industry.......

 Swarfy.

Offline BSA_54A10

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Re: Another great old photo
« Reply #29 on: 10.03. 2023 06:58 »
And for completeness, the names of the folk in GB's pic, some pretty familiar  . . .

"Matchless dealer Angus Herbert (second from left) outside his agency. Others are Bruce Main-Smith, then Herbert, the shop manager,  AMC's Mike Marriot and Motor Cycling staffman Mike Bashford. The machines are ISDT models, with two 350s sandwiching a 500."

Yes it had to be a staged PR shot
Thank you for that
I know virtually nothing about any make other than BSA but I should have recognised the young BM-S
Bike Beesa
Trevor