The Beginners Questions Area

It's OK to teach simplified models, if the student is warned that they are simplifications.

I remember in third grade we were learning subtraction (something I'd taught myself earlier, but there's no accommodation for that in grade school. : “What do you get when you subtract 3 from 2?”. I was the only student who raised my hand. She called on me.

“Minus 1,” I said, with a lot of confidence. That confidence was based on reading. My mother’s brother, Uncle Bill, taught math at Choate, and he and two other faculty members had written a set of high school textbooks. We had copies of all of them. One of them was called Elementary Algebra. I’d been reading that algebra book at home before dinner.

Minus one wasn’t the answer my teacher was looking for. She told me, and the class, in emphatic terms, that you can’t subtract three from two, you had to borrow from the column to the left to make the 2 into 12, and then you could subtract 3, leaving you with 9. I argued my case and was overruled. The next day I brought the text in and showed her. She said it was wrong. Not just wrong in the context she intended, but flat wrong. I was uncowed, but finally shut up. She didn’t call on me much after that.

That sticks in my mind partially because the injustice seemed like a big deal to a 9-year-old boy

In the UK, the school exam levels are GCSE taken at age 16 and GCE Advanced level taken at 18. The A levels are exams used for entry to university. Now it's quite interesting looking at the teaching of chemistry at the various levels. I was told by an A-level teacher than some of the concepts taught at A-level first require un-teaching the simplified version taught at GCSE. And to some extent, if you go on to undergraduate level, some of the concepts taught at A-level are found to be over-simplified and effectively incorrect.

It's this kind of approach I'm referring to. If it takes 5 years of study to work up to an understanding of a particular topic, it may well do that a dumbed down version is just fine at a lower level. I'm sure there are many concepts of digital photography that require a deep understanding of (say) quantum mechanics to fully understand. But you don't need to know the uncertainty principle to get a working grasp of how to manage noise in your photographs. That's my point really.

I’m reminded of Tom Lehrer’s “The New Math”.

LOL....OK. Good point. But to a beginner.....

This kind of exemplifies the issue with experts and teaching. When I say Newtonian mechanics, I don't think tensors and all that stuff, I think F=ma, calculating velocity changes, literally the first 3 things a student would ever hear about. A beginner photographer, who just put aside their phone and picked up their brand new dedicated camera for the first time does not want to learn tensors and complex vector operations, they need to learn the difference between speed and velocity. What is a lens, what is a shutter speed, what does it do, why is this important...basics. You don't need to know the uncertainty principle to get a working grasp of how to manage noise in your photographs.Baby steps, bite sized chunks.

The problem is incorrect answers to basic questions. Saying that a correct answer is too complicated for a beginner is not the same as giving a correct and understandable answer.

Easier to discuss by example than in the abstract.

I've attempted to write a dumbed down but hopefully useful beginners style answer here. I hope I haven't given incorrect info

dprevived.com/t/is-f4-always-f4-even-on-a-different-sensor-size/1137/

Another thought on this:

The teaching of (complex) subjects at school basically follows the history of scientific discovery - hence Newton before Einstein's Special Theory before his General Theory of Relativity; Dalton's atoms before Rutherfords model before the Bohr model, etc, etc. Hopefully the student will be learning ever more advanced mathematics in parallel so that they can move onto the more complex theories at the appropriate time

With digital photography there is no such history - for example no "expert" ever believed that increasing ISO increased the sensitivity of the sensor (and yet I have seen this stated with what seems absolute certainty by some). So let's teach it right from the get go

Tim

I broadly agree with the folks in favour of simplified, abstracted teaching points for beginners even if they aren't completely accurate. For example, f/stops:

For a beginner, talking about exposure, the important thing to know is that any lens at f/2.8 on your camera gives the same brightness in the final image, so swapping between a 50mm at f/2.8 and a 100mm f/2.8 while shooting under the same conditions gives the same result (excepting the obvious difference in field of view).

But actually.. f/numbers are theoretical and different lens designs will have slight variations in transmission at the same f/stop, hence why cinema lenses use t/stops instead. And actually, some lenses vary in this behaviour by focus distance- my old Canon 100mm f/2.8 macro was only f/2.8 at infinity, by the time it was at 1:1 distances it was more like f/5.6. And actually, some lens manufacturers have played fast and loose with claimed f/numbers for marketing purposes.

A beginner doesn't need to know all the nuances and edge cases. They need to know that if they are photographing under consistent conditions, with a consistent shutter speed and ISO, they can keep the f/number consistent and get a consistent exposure output.

Iris in the eye "works" automatically, comparing aperture to it may introduce a wrong idea.

If you hunt around the web, look in magazines, even some text books on photography you'll see plenty of advice about how to play with perspective photographically. Many, many of these sources will explain the effect of wide angle lenses and tele lenses as such: if you want to generate exaggerated perspective such as portraits with giant noses and goblin features or distant mountains that look like cardboard cutouts, you'll need to use the right lenses. Tele lenses compress perspective making everything look the same size. Wide lenses exaggerate perspective.

Now as any expert will tell you, you don't play with perspective by changing focal length, you do it by changing camera to subject distance. But many, many quite experienced, even successful photographers swear that tele lenses compress perspective and wide lenses expand perspective. This information is everywhere and it is wrong. This has long been a bugbear of mine.

But when I contemplate what this means for teaching, it occurs to me that it might be successful because even though it is wrong, if you believe it is correct the chances are you will still end up taking the pictures in the style you wanted. It's wrong but it by a happy accident it still gets the job done. The fact that it works for the wrong reasons feels wrong, but at a pragmatic level the idea does work. I mean, no one I know has ever shot a distant mountain range with an ultra wide angle lens, blown up 1% of the image to A2 and proudly proclaimed "Look beautiful cardboard cut out layered mountains, aren't ultra wides great!". No, they would just stick a tele lens on and get a nice shot.

Teaching is a subtle art, pedantry isn't necessarily the only way to do it.

You might be right, Iliah. Nothing in teaching is 100% perfect and soon as you use analogy it will break down at some point. However, in this case I'm fairly confident, that in the large, that little analogy is going to do more good than bad for beginners. I'm pretty sure my wife's friend would get the basic idea. And later on, if she becomes more knowledgeable she'll refine the model herself without any difficulty.

Compare that to a highly detailed, engineeringly correct explanation of the lens iris that would satisfy a professor. How many people would actually get past the first sentence before tossing it aside and taking up crochet?

Is this analogy really necessary?

the bottom line is - proponents of simple answers shall chime in PRONTO in the topic posted by "beginner" and give those short answers faster to preclude heavy hitters appearances ... but be ready to be challenged if their short answers are found / thought to have "error(s)" ...

proponents of detailed answers shall create TOPICs in dprevived.com/c/photographic-science-and-technology/71/ and then simply give links to such topics to "beginner" and let him/her/them swim or sink ... people can't be force fed if they want to die ignorant

I can't count the number of times I've tried to convince people that changing the format doesn't change the perspective. There are still people that are convinced that medium format affords different perspective options than FF or MFT, and it's hard to convince them otherwise, even with demonstrations. This is a result of learning something that is wrong at the beginning, and not letting go of it. And it's damaging their photography, or at least getting them to choose the wrong cameras. As Bob has said, it's harder to unlearn something than it is to learn the right thing.

Yes, exactly. Experts are experts, they considered the subject deeply for a long time. They understand every nuance and when these nuances will affect the result. They care about those details. And anyone who wants to become an expert themself better care about them, too. But there are plenty of instances where you don't need to be an expert. You just need a rule of thumb to get the job done. Maybe later you'll want to be an expert.

An interesting example to me is something Jim said about ISO. In the midst of a complicated debate about optimising exposure strategies he said something along the lines of "this will allow you to reduce noise by 1/3rd of a stop" - I paraphrase, so I'm probably misquoting. But the principle of optimising something to a third of a stop is an expert's principle. A beginner is nowhere near this level of precision. If they can learn a rule that will get them within a stop or two of the optimum, they'll likely be very pleased and their enthusiasm boosted. Refining this to a stop , half a stop and eventually 1/3rd of a stop can wait until they've got through the first week. You don't start out as an expert, you work your way up. I suspect a lot of experts completely forget their first 5 years of learning. There is no royal road. Baby steps until you reach the level that works for you. Then go upwards and onwards if you want to. This is why I think it would be useful to structure things in levels: Absolute novices, been using my camera for a couple of months, experienced, master, Engineer/scientist. You don't need quantum mechanics in the absolute beginner forum, you may need it in the scientist forum.

I don't think this is a relevant example, I never saw a knowledgeable photographer explaining this to a beginner other than in a sort of PS. "but there is more to it".

BTW, the aperture f-stop values represent relative apertures which are calculated from the focal length of the lens divided by the diameter of the entrance pupil for a lens focused on infinity.

I know what you are saying and I don't disagree with it in principle. But you can introduce people to a simplified version of a concept that is easy to grasp and then complexify it later when they are ready and they can benefit from it. Giving people a PhD thesis as their first sight of a photographic concept won't work for most people. Maybe for Jim or IIiah, smart people who think very conceptually and precisely but for a beginner who knows nothing, that thesis will likely just result in them packing it in. For a lot of people, when you introduce them to scary technical stuff it's really really really important to build their confidence, not terrify them. Photography should be for everyone, not restricted to those with an Ansel Adams grasp of the technicalities. I don't know anything much about David Bailey but I suspect he wouldn't be the first person to ask about photon shot noise statistics, but he's had a fine photographic career nonetheless.