Video: The Three Basics, ATARI style

[MatthewGore]

Those of you who were alive in the Era of the Commodore 64 and Atari (or really even the early NES) may appreciate this video... even if you already know this stuff



(It's probably worth putting this in HD mode, for some of the examples)

I was writing an article about the 3 basics (Aperture, ISO, and Shutterspeed) last autumn, and ended up using the old "Bucket and Water Pipes" analogy to explain the relationship. Some people still seemed to be finding it a little confusing, and I wanted to come up with a more visual explanation, so I ended up creating this video. As I was animating it, the cubes reminded me of an old video game, so it sorta took on a vintage theme

Hope that some of you find this useful!

- Matthew Gore

 

[KmH]

You might want to show the shutter curtains moving in the direction they actually move (3:20 or so), which is from the top of the shutter opening to the bottom of the shutter opening.

It would have to be pretty dark to get a good exposure using 1 sec, f/2.8, ISO 400.

 

[MatthewGore]

Ahh yes, I guess I wasn't thinking when I animated my fake shutter I'll have to keep that in mind next time... thanks!

Of course, I chose to use 1 second as the shutter speed so that the math was immediately, intuitively obvious for people who aren't familiar with shutter speeds... figured that 1, 2, 4 was easier than 1/250, 1/125, 1/60.

- Matthew

 

[KmH]

I figured that was what you were doing, and no doubt you put a lot of work into the video. :thumbup:

I think it is better to use real numbers like 1/4000, f/2.8, ISO 400. People aren't going to be using 1 second shutter speeds very often, unless they are shooting products with continuous lighting.

The fact 2.8 isn't 2 times less than 4 might be confusing too.

 

[MatthewGore]

The fact 2.8 isn't 2 times less than 4 might be confusing too.

Not quite sure I catch your meaning there; f/2.8 IS exactly half as much light as f/4... its one stop. Did I word it wrong? (Sorry, I can't stand to watch that video another time and find out )

- Matt

 

[MatthewGore]

Oh, you mean the numbers themselves... yes, of course you're right. I wrote more about that in the article that this video goes along with, but I think I edited out the bit that explained that in the video. G

 

[TCampbell]

GREAT video! I'll probably make several people watch this.

A few comments...

So... there is "technically" a number 4. Don't forget that in addition to changing the settings on your camera you may ALSO be able to change the amount of light on your subject. So #4 (using lighting to change the exposure) is a slightly more advanced topic, but it is a consideration that people sometimes forget. If I get the "my camera isn't very good at shooting photos in this dim light" my reply is usually "then why not take the photo where there is more light?" I grew up shooting film. We didn't have 6400 ASA film.

Just about every book on exposure ignores lighting -- I'm guessing this is why so many people panic when they have to use a flash. It's like black magic -- something only few can control and everyone else should fear it. I always try to remind people... there is "one more thing" you can use when you've exhausted the limits of the exposure triangle.

I'm not sure I'd try to add a section on lighting to your video... I'd probably just mention that taking a photo where there is more light is also an option. You could easily take one of your arrays of light dots (photons) and create a checkerboard pattern to show a room with "half the light" and it's impact on the exposure.

You might also want to expand your explanation of f-stops a little. f-stop numbers are the most confusing to people because the numbers seem arbitrary when you don't know what they mean. Shutter speeds and ISO sensitivity doubling and halving makes sense to people because the numbers really do double and halve. When people understand that f-stop numbers aren't actually arbitrary then it makes a lot more sense.

I usually have to explain that the "f" in "f-stop" stands for "focal ratio". And it's the ratio of the focal length of the lens divided by the diameter of clear aperture. So a 50mm lens with a clear aperture set to 25mm wide is using f/2. A 100mm lens with a clear aperture approximately 9mm in diameter would be f/11 (and we'd have to round that off because 11 x 9 is only 99... not 100 -- but hey, that's close enough (and technically the camera companies DO round off.)

As for the halving and double aspect of f-stops... they're "powers" of the square-root of 2. The square root of two (rounded off to just 1 decimal place) is 1.4. So f/1 is actually the square root of 2 raised to the 0 power (anything raised to the 0 power is always 1.) f/1.4 is the square root of 2 raised to the 1st power (or simply the square root of 2... itself.) f/2 is the square root of 2 raised to the 2nd power. And if you keep playing this out the progression is 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, and 32. The other thing to notice is that every other value is doubled (1, 2, 4, 8, 16, & 32 and the values between are 1.4, 2.8, 5.6, 11 (which is just a round off of 5.6 doubled), and 22. This whole square root of 2 thing is due to the "inverse square law" (and if someone wants to read more about it or even visualize it there are lots of good articles.) The SAME "inverse square" law turns out to be very handy when you're dealing with lights and their distance from the subject... but that's more advanced.

The other analogy I often use is that comparing a lens to a long tunnel. For a lot of people it doesn't make sense that merely making a lens "longer" should reduce the amount of light that arrives on the far end of it. But most people would intuitively expect it to get darker the farther they go into a long tunnel. If I'm standing 10' inside the entrance of a tunnel which is 10' in diameter, there's a lot of light around me. But if I'm 100' inside a tunnel which is only 10' in diameter, it's pretty dark. If, however, I bored out the tunnel to make it 100' in diameter, then it would be just as bright at 100' inside a 100' diameter tunnel as it is when you're just 10' inside a 10' diameter tunnel. If the "ratio" of length to diameter is the same, then the amount of light is the same.

Thanks for posting that! You did a superb job at simplifying the three on-camera exposure controls into a way that I think most people can probably understand.

 

[MatthewGore]

Hi Tim,

Thanks You're right about flash/artificial light, and I'm saving it for another video!

This video was actually made as a companion to two articles that I wrote on my site, Light and Matter: the "Three Basics of Photography", and "The Unifying Theory", where I cover these things in more depth (though even there I buried some of the scary details in footnotes). The idea was that this video would help ease people in, giving them the general idea so that it would be easier for them to pick up the details in the articles (and the rest of the site). Incidentally, I also have an interactive quiz on my site (about the two articles, here ), and in the quiz, I did throw in a question about flash, even though I hadn't breached the topic in the articles yet.

I had tried making videos on this subject previously that contain all of these wonderful details, but they get bogged down and boring pretty quickly, and the audience that I'm trying to capture with videos (ie, beginners who are visual learners) tends to get scared off by numbers, so I leave them out when I can get away with it.

Anyway, thanks for the additional information and suggestions! I love the tunnel analogy... I'm going to use that

 

[o hey tyler]

GREAT video! I'll probably make several people watch this.

A few comments...

So... there is "technically" a number 4. Don't forget that in addition to changing the settings on your camera you may ALSO be able to change the amount of light on your subject. So #4 (using lighting to change the exposure) is a slightly more advanced topic, but it is a consideration that people sometimes forget. If I get the "my camera isn't very good at shooting photos in this dim light" my reply is usually "then why not take the photo where there is more light?" I grew up shooting film. We didn't have 6400 ASA film.

Just about every book on exposure ignores lighting -- I'm guessing this is why so many people panic when they have to use a flash. It's like black magic -- something only few can control and everyone else should fear it. I always try to remind people... there is "one more thing" you can use when you've exhausted the limits of the exposure triangle.

I'm not sure I'd try to add a section on lighting to your video... I'd probably just mention that taking a photo where there is more light is also an option. You could easily take one of your arrays of light dots (photons) and create a checkerboard pattern to show a room with "half the light" and it's impact on the exposure.

You might also want to expand your explanation of f-stops a little. f-stop numbers are the most confusing to people because the numbers seem arbitrary when you don't know what they mean. Shutter speeds and ISO sensitivity doubling and halving makes sense to people because the numbers really do double and halve. When people understand that f-stop numbers aren't actually arbitrary then it makes a lot more sense.

I usually have to explain that the "f" in "f-stop" stands for "focal ratio". And it's the ratio of the focal length of the lens divided by the diameter of clear aperture. So a 50mm lens with a clear aperture set to 25mm wide is using f/2. A 100mm lens with a clear aperture approximately 9mm in diameter would be f/11 (and we'd have to round that off because 11 x 9 is only 99... not 100 -- but hey, that's close enough (and technically the camera companies DO round off.)

As for the halving and double aspect of f-stops... they're "powers" of the square-root of 2. The square root of two (rounded off to just 1 decimal place) is 1.4. So f/1 is actually the square root of 2 raised to the 0 power (anything raised to the 0 power is always 1.) f/1.4 is the square root of 2 raised to the 1st power (or simply the square root of 2... itself.) f/2 is the square root of 2 raised to the 2nd power. And if you keep playing this out the progression is 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, and 32. The other thing to notice is that every other value is doubled (1, 2, 4, 8, 16, & 32 and the values between are 1.4, 2.8, 5.6, 11 (which is just a round off of 5.6 doubled), and 22. This whole square root of 2 thing is due to the "inverse square law" (and if someone wants to read more about it or even visualize it there are lots of good articles.) The SAME "inverse square" law turns out to be very handy when you're dealing with lights and their distance from the subject... but that's more advanced.

The other analogy I often use is that comparing a lens to a long tunnel. For a lot of people it doesn't make sense that merely making a lens "longer" should reduce the amount of light that arrives on the far end of it. But most people would intuitively expect it to get darker the farther they go into a long tunnel. If I'm standing 10' inside the entrance of a tunnel which is 10' in diameter, there's a lot of light around me. But if I'm 100' inside a tunnel which is only 10' in diameter, it's pretty dark. If, however, I bored out the tunnel to make it 100' in diameter, then it would be just as bright at 100' inside a 100' diameter tunnel as it is when you're just 10' inside a 10' diameter tunnel. If the "ratio" of length to diameter is the same, then the amount of light is the same.

Thanks for posting that! You did a superb job at simplifying the three on-camera exposure controls into a way that I think most people can probably understand.

Tim, I'm glad you joined the forum. You seem like a very level headed guy with a firm grasp on photography. I've read a few posts of yours that I agree with 100%. Plus, you're a fellow 5D2 user, and that is worth something in my book.

 

[TCampbell]

Tim, I'm glad you joined the forum. You seem like a very level headed guy with a firm grasp on photography. I've read a few posts of yours that I agree with 100%.

thanks! I started apprenticing for a professional wedding photographer back when I was 16 (over 30 years ago)... I worked for him for a lot of years and saw a lot of weddings (I never really counted them, but years later I looked at the average number of weddings per year times the number of years and I think I've probably done maybe 500 weddings.) I don't work professionally anymore -- my career is in another field, but I still love the camera. I've had the pleasure of meeting several great photographers (I once got scolded by Alfred Eisenstaedt... I met him at a photo exhibit when he was 93. Someone wanted me to take their photo with him and, being the "wedding" photographer I started to set up the shot. It turns out Alfred Eisenstaedt didn't believe in "posed" shots... like... not at all. <sigh>. I guess you live & learn.) I try to learn and absorb as much as I can from as many different people as I can -- including different types of photographers and didn't approaches to shooting. I'm a firm believer that photographic mastery is a journey and not a destination. Nobody ever really "arrives." I'll bet Ansel Adams wasn't a very good sports photographer.

I'm a mod over at the sister site to this one (photoforum.com - owned by the same folks as TPF) and figured I'd pop over here some of the time.

Plus, you're a fellow 5D2 user, and that is worth something in my book.

LOL - that got a laugh and a smile. Thanks for the welcome!

 

[Netskimmer]

Nice vid, pretty easy to understand. The only problem is now I have this incredible urge to dust off one of my emulators and "pop in" a ROM of old school Zelda or Dragon Warrior!:geek:

 

[KmH]

Oh, you mean the numbers themselves... yes, of course you're right.

Yep, the numbers themselves.

And since 4 is a larger number than 2.8, people may not get how it is that f/2.8 can let in 2x more light as f/4 does, since most people have a mental block when it come to fractions and don't get that f/2.8 is actually a bigger number than f/4 is.

 

[TCampbell]

Oh, you mean the numbers themselves... yes, of course you're right.

Yep, the numbers themselves.

And since 4 is a larger number than 2.8, people may not get how it is that f/2.8 can let in 2x more light as f/4 does, since most people have a mental block when it come to fractions and don't get that f/2.8 is actually a bigger number than f/4 is.

That's why I explain that the number is the ratio of the lens' focal length divided by the diameter of clear aperture. In essence, a shot taken with a 100mm lens and a 25mm diameter clear aperture is f/4 because 100 ÷ 25 = 4. But if the aperture opening is reduced to only 12.5mm diameter then it's f/8, because 100 ÷ 12.5 = 8. Then they can understand that even though the open gets smaller, the aperture value expressed as an f-stop gets larger.

This ultimately goes to how people learn. Some people can memorize information and they can learn and repeat instructions. Other people are terrible at the memorization aspect but it will all make sense to them if they could just understand the mechanics behind how something works. The diagrams in this video (which are great, btw) seem to be catering to the person who needs to understand the mechanics of how the thing works. My suspicion is that those who need that method to learn will also need to understand why f-stops aren't really just arbitrary numbers someone made up, but there's a real meaning to those values.

 

[MatthewGore]

It seems that I stopped getting email notifications about updates to this thread... sorry for the late reply.

Tim, I agree that the origin of the values is worth knowing. I included the same information (almost the same example, even) in the second article linked above:

The amount of light let through a lens is dependent on two things: the focal length of the lens and the diameter of the aperture opening. Therefore, the f-number = focal length (mm)/ aperture diameter (mm). So, a 100mm lens with an aperture opening of 25mm = f/4 . If you feel like practicing your geometry, you can calculate the area of each aperture for a given lens, and you&#8217;ll find that the area doubles from one f-number to the next.

As I say, though, it just didn't make the cut for the video; trying to keep it down to about 10 minutes, there were just some things that I had to leave out. It's also worth knowing (and perhaps more practical) that the f-stop numbers themselves double/half every two stops, while the numbers for ISO and Shutter Speed double/half with every single full stop... and of course, I didn't even mention intermediate positions (1/3 or 1/2 stops). Again, trying to keep things brief, I really wanted to give a broad overview rather than a complete lesson.

In the next videos, I suspect that I'll tackle lighting, understanding histograms, and exposure compensation (+the zone system?).

- Matthew