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Forum: Winners' Showcase 07-06-2023, 04:31 PM

June, 2023 Winner: My best friend, Buckley
Posted By Don Heath

Replies: 94
Views: 669

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Forum: Monthly Photo Contests 02-15-2023, 04:51 PM

Poll: Expired Contest Poll VOTE NOW - Photo Contest #197 Poll (Best of 2022 - January 2023)
Posted By Don Heath

Replies: 30
Views: 3,106

#5. Really tough call but sometimes the answer is right there, staring you in the eye!

Forum: Monthly Photo Contests 12-01-2022, 06:43 PM

Seniors watching
Posted By Don Heath

Replies: 33
Views: 337

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Forum: Monthly Photo Contests 09-02-2022, 03:55 PM

Lecht Cloud
Posted By Don Heath

Replies: 54
Views: 373

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Forum: Troubleshooting and Beginner Help 05-17-2022, 06:06 PM

What is "One Stop"?
Posted By Don Heath

Replies: 68
Views: 3,895

Back in the pre-digital days, Eastman Kodak used to sell pocket cards that worked like slide rules for determining the proper exposures for various lighting situations. If you could find one of those, perhaps from an older photographer, it would be a big help to you. Keep in mind that f/8 on a 28mm lens is not the same size opening as f/8 on an 85mm lens (assuming that both lenses have the same size mount) because the f/stop is a ratio of the size of the lens opening (the aperture) to the distance from the optical center of the lens to the film or digital sensor and the different lenses have optical centers at different points. In fact, if you look at either lens set to f/8 (or any other stop) from the back and then from the front, it will appear that the stop has changed sizes! This is an optical illusion produced by the different levels of magnification in the different lens elements.
And if that isn't confusing enough, if you could hop into the wayback machine and travel back in time to watch Matthew Brady at work photographing the civil war, you might notice that his lenses didn't have internal iris mechanisms so lens openings had to be set by sliding a metal card with a certain size opening that would slide into a slot in the top of the lens so that the correct lens opening would appear at the optical center of the lens. These openings were called T/Stops and were more accurate than todays f/stops but not so much so that the slight loss of precision couldn't be replaced by the convenience of an adjustable in-lens system like we have today.

Forum: Monthly Photo Contests 05-08-2022, 05:04 PM

Chicago's Bean
Posted By Don Heath

Replies: 45
Views: 490

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Forum: Monthly Photo Contests 04-07-2022, 09:32 PM

Arco Ires in Portrait
Posted By Don Heath

Replies: 6
Views: 137

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Forum: Monthly Photo Contests 03-08-2022, 05:44 PM

Adams Falls
Posted By Don Heath

Replies: 24
Views: 236

I would like to nominate this photo