This is a handout that I came up with for one of my photography classes I teach (Page 9): My "commentary" was a response to the question that RCJets asked. I think I'll leave it at...

R.G. Loc: Scotland

Abo wrote:

Can you tell us RG, in the immortal words of Professor Julius Sumner Miller; "why is it so?" vis a vis
your aperture commentary.

My "commentary" was a response to the question that RCJets asked. I think I'll leave it at that.

rmalarz Loc: Tempe, Arizona

Let's try to stay with the topic of exposure as related to photography.
--Bob

BebuLamar wrote:

If two people sunbathing at the same location and at the same time. The two people receive the same exposure to sunlight although one of them has a serious sunburn and the other one is not. That doesn't mean the one with sunburn got more exposure to sunlight.

BebuLamar

rmalarz wrote:

Let's try to stay with the topic of exposure as related to photography.
--Bob

What I meant is that exposure always means intensity x duration regardless of what kind of exposure you're talking about. My example is that given the same exposure a low ISO film can have underexposure and a high ISO film can be overexposed although the exposure are the same.
In other word it's not 3 sides but rather 2 sides.
1. Side one the amount of exposure which is controlled by aperture and shutter speed.
2. Side two the exposure requirement for correct exposure which is the sensitivity or ISO.
So the one side is supply and the other is the demand.

BadPhoto Loc: Maryland

grandpaw wrote:

I have posted this before but it may help a lot of new photographers understand their camera settings.

The graphic could be correct with just a few simple changes. Otherwise, new photographers may get an inadequate understanding of their camera settings. Most specifically, what constitutes a "correct exposure".

The aperture controls the light through the lens and into the camera. It controls depth of field (larger number, smaller aperture, greater depth of field) but if the aperture is too small the image will be less sharp due to diffraction.

The shutter speed controls the duration of the exposure, and with aperture the amount of light captured by the sensor. It controls motion blur due to moving subjects or camera motion.

Aperture and shutter speed control the total amount of light captured by the sensor. Too little light, and the image will be underexposed with crushed darks and too much noise. Too much light, and the image will be overexposed with blown highlights.

The ISO controls the brightness of the image, as well as the aperture and/or shutter speed settings in auto-exposure modes. For optimal exposure, the ISO should be set at base ISO, and set to a higher value only if the aperture cannot be opened more (due to lens limits or depth of field requirements) or shutter speed lengthened (due to motion blur of moving subjects or camera motion).

rmalarz Loc: Tempe, Arizona

Well, it should be apparent that after 9 pages of replies, something is inherently incorrect or misleading about this handout. Perhaps its time for ver. 1.1.
--Bob

grandpaw wrote:

I have posted this before but it may help a lot of new photographers understand their camera settings.

juan_uy Loc: Uruguay

rmalarz wrote:

Well, it should be apparent that after 9 pages of replies, something is inherently incorrect or misleading about this handout. Perhaps its time for ver. 1.1.
--Bob

After these 9 pages I am convinced that how you mentioned that you describe using a balance scale (https://www.uglyhedgehog.com/tpr?p=12550694&t=711224) is way more exact than the exposure triangle.
And personally even clearer.

Will keep in mind that explanation whenever I need to explain it from now on

rmalarz Loc: Tempe, Arizona

Thanks, Juan. I appreciate the compliment.
--Bob

juan_uy wrote:

After these 9 pages I am convinced that how you mentioned that you describe using a balance scale (https://www.uglyhedgehog.com/tpr?p=12550694&t=711224) is way more exact than the exposure triangle.
And personally even clearer.

Will keep in mind that explanation whenever I need to explain it from now on

frankraney Loc: Clovis, Ca.

rmalarz wrote:

Let's try to stay with the topic of exposure as related to photography.
--Bob

I think he have one of the best explanations over I've heard. He explained sensitivity very well. Which is what iso is.

POVDOV

I'm a little late to this party. I think the chart is an excellent teaching tool. Explaining ISO is some physics and chemistry. Sensitivity is a wonderful word to use in explaining ISO.

cjc2 Loc: Hellertown PA

While it may be technically incorrect, it does do an excellent job of illustrating a point to a class new to photography. There are many choices of words available which would make the description technically correct, but we like to talk about the 'Exposure Triangle" of which film speed, or sensor sensitivity, is a equal part. The biggest difference between analog and digital is that, with digital, the ISO is easy to change, without swapping out the film. Best of luck.

frangeo Loc: Texas

grandpaw wrote:

I have posted this before but it may help a lot of new photographers understand their camera settings.

rmalarz Loc: Tempe, Arizona

One could question how it could do an excellent job if it is technically incorrect.
--Bob

cjc2 wrote:

While it may be technically incorrect, it does do an excellent job of illustrating a point to a class new to photography. There are many choices of words available which would make the description technically correct, but we like to talk about the 'Exposure Triangle" of which film speed, or sensor sensitivity, is a equal part. The biggest difference between analog and digital is that, with digital, the ISO is easy to change, without swapping out the film. Best of luck.

JVada Loc: OH

Charlie- pretty clear statement. May I add a little tickle to what you said @ the end…and that is
“iso affects shutter “And/Or” aperture dependent on how (rapidly) changing the light conditions are. Especially if in auto iso mode, which I rarely use except in certain situations( but I digress).

BebuLamar

rmalarz wrote:

Charlie, exposure is simply amount of light and duration of that amount of light. It becomes a photographic exposure when a photosensitive material is placed at the receiving end of that aforementioned light.

Yes, photography is somewhat technical and conversations regarding photography need to have commonly understood terms in order to have those conversations have clear meaning.
--Bob

I agree with you fully. You can ignore the technicals but when you talk about it, it should be correct or just don't talk about it. One can take great pictures without technical knowledge.

Bill_de Loc: US

The thread is nine pages long and a year and a half old. One thing UHH is famous for is it never lets a sleeping dog lie.

Everyone know what ISO stands for?

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