Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Photography for geeks

lcamtuf.coredump.cx

Post reply on HN
Print view View original

31–40 of 150 posts

Re: Photography for geeks

#31

Post by geokon »

CWuestefeld wrote: post #12
geokon wrote: post #7

Earlier quoted context omitted.

I think when you break down all the variables there is really very little to play with bc no phones have variable apertures. ISO is basically a linear gain that's done on the sensor. As long as you aren't blowing out your photo and loosing information, it basically makes not difference if you do it in sensor or later while editing So the only variable left is the shutter speed - which is basically directly dictated b…

ISO is basically a linear gain that's done on the sensor. As long as you aren't blowing out your photo and loosing information, it basically makes not difference if you do it in sensor or later while editing This is true for some cameras, but certainly not all. Many cameras, especially pro or pro-sumer grade, have non-linear ISO. That is, there are ranges for which it behaves linearly, but typically there will be som…

"then the next setting up from that will reset to a lower snr"

How does it magically make more photons fit the sensor..?

And why wouldn't you use that same magic at lower iso gain factors?

Re: Photography for geeks

#32

Post by [deleted] »

kyleyeats wrote: post #27
lelandfe wrote: post #26

Earlier quoted context omitted.

A lot from the article will not work, because the terms are too overloaded ("three point"). SD photography and lighting keyword dump I've tested for 1.5: f1.8, dof, bokeh, soft focus, chiaroscuro, backlit, golden hour, soft lighting, natural lighting, warm colors [but not "cool"], Polaroid, lens flare "85mm", "50mm" etc all make the image realistic, but don't do anything specific. Pro-tip: use "windows" to get many o…

Thanks for these. Can vouch for golden hour . I can see why directors are obsessed with it.

[deleted]

Re: Photography for geeks

#33

Post by oogali »

bradknowles wrote: post #30
muglug wrote: post #24

The main thing about photography is your first 10,000 photos will likely be bad. Modern technology makes it possible to get through 10,000 snaps much faster and much cheaper than when using film. But taking those photos is not enough — it’s in the editing of those first 10,000 photos that you will find the hidden photographer in you. Photography is a lot like writing code: you can create something that does the job,…

I wouldn't say it's your first 10k photos. Because anyone can just hold down the button and take hundreds of photos. And those hundreds of photos don't really count as separate pictures in this regard. I would say that it's more like your first 10k different photographic compositions/subjects. From there, I agree that you really learn in the editing.

For me, it truly was after my first 10K photos — speed shutter and all.

Once you sit down and go searching through that burst for the perfect or otherwise usable photo of that burst, you start to notice the small things: the slight detail changes at the edges, what may have transpired between captures, how a light source that changes in milliseconds can affect the overall feeling.

It took me about 2.5 years to reach that point. Shooting at different times of the day, different seasons. Countless hours tweaking levels and cropping in Photoshop, Capture One, etc. Lots of changes in gear: UV/haze filters, circular polarizers, tripods, zoom lenses, prime lenses. Flashes, reflectors, gray cards. Exploring the different modes on my camera, Magic Lantern firmware, etc.

It all counts. But the post processing is the crucial part of the feedback loop.

Re: Photography for geeks

#34

Post by semireg »

The things I’m drawn to in life is where art meets science. In hindsight, so much of the secret is knowing how to avoid failure. Baking bread? Build the intuition over time and you’ll realize baking is forgiving so long as you don’t do these “5 bad things.” Gardening/farming? Yeah, there’s a big list of bad things. Brewing beer? Another list of things to avoid. The basic rules (rooted in science) are like guardrails and everything else is the art. I love this so much.

In my early 20s I had a week long mind meld knowledge transfer from a self taught photographer. It made me fall in love with photography. I’m still using it to this day to photograph new label printers (black plastic is terrible to photograph) and labels (oh god they are 2D!).

I’m doing an OK job. Room for improvement but fine for the initial launch. You can see them here: https://mydpi.com/products/professional-synthetic-direct-the...

In case you’re like “why is this guy selling label printers?!”

I’m a solo software dev that wrote Label LIVE (electron) to design and print labels. Now I’m vertically integrating with a printer I’ve imported from China and labels made in the USA.

Business and entrepreneurship: just avoid these 9999 things and you’ll be fine! Science and art…

Re: Photography for geeks

#35

Post by spindle »

CWuestefeld wrote: post #12
geokon wrote: post #7

Earlier quoted context omitted.

I think when you break down all the variables there is really very little to play with bc no phones have variable apertures. ISO is basically a linear gain that's done on the sensor. As long as you aren't blowing out your photo and loosing information, it basically makes not difference if you do it in sensor or later while editing So the only variable left is the shutter speed - which is basically directly dictated b…

ISO is basically a linear gain that's done on the sensor. As long as you aren't blowing out your photo and loosing information, it basically makes not difference if you do it in sensor or later while editing This is true for some cameras, but certainly not all. Many cameras, especially pro or pro-sumer grade, have non-linear ISO. That is, there are ranges for which it behaves linearly, but typically there will be som…

This is a great resource for finding out which ISO ranges various cameras are linear over:

https://photonstophotos.net/Charts/RN_e.htm

Re: Photography for geeks

#36

Post by timbeccue »

geokon wrote: post #31
CWuestefeld wrote: post #12

Earlier quoted context omitted.

ISO is basically a linear gain that's done on the sensor. As long as you aren't blowing out your photo and loosing information, it basically makes not difference if you do it in sensor or later while editing This is true for some cameras, but certainly not all. Many cameras, especially pro or pro-sumer grade, have non-linear ISO. That is, there are ranges for which it behaves linearly, but typically there will be som…

"then the next setting up from that will reset to a lower snr" How does it magically make more photons fit the sensor..? And why wouldn't you use that same magic at lower iso gain factors?

The base stops are ISO 100, 200, 400, etc.

Many cameras let you set the ISO in 1/3 stop increments, but if I recall correctly, many camera manufacturers just keep the sensitivity at the base stops and adjust the brightness via software.

So shooting at ISO 250 really means ISO 200 (underexposing what you requested) but then adding a third stop equivalent of brightening to the digital file. Conversely, using ISO 160 actually means the camera is using ISO 200 (overexposing) and lowering the brightness in software.

What this means, at least 10 years ago when I was more in tune with the photography world, is that people would prefer to shoot at the [base ISO stop - 1/3] levels to because those were the levels with the least noise near that exposure setting. The cost is you risk saturating more pixels in the highlights.

And for the same reasoning, the ISO setting s 1/3 over the base stops were typically avoided as they were noisier, albeit with slightly more dynamic range.

Re: Photography for geeks

#37

Post by gofreddygo »

throw0101c wrote: post #5

If anyone wants to move beyond using the "auto" setting on their camera (or phone), I would recommend the book Understanding Exposure by Bryan Peterson, the first edition of which was published in 1990: * https://www.goodreads.com/book/show/142239.Understanding_Exp... The principles involved haven't changed much in the intervening decades; the current fourth edition was publish in 2016. If all you have is a phone you…

Aperture Size, Shutter Speed and ISO. Just understand what they are. And their units.

Actually see pictures varying one and keeping others constant to get a hang of things.

Then go backwards, check professional pictures and guess the values. Professional photography forums all photos have these values published .

Night/Day photography, moving/still and background focus are the only 3 skills you need as an amateur photographer. They rely on the 3 settings above.

Beyond that lies the rabbit hole that, if you venture, speak not to any people whom you wish to keep friends. They hate when you try to tell them.

Don't spend over 2k on lenses.

Have printed photos on glossy, matte paper. Touch and feel them. Worth the time.

Re: Photography for geeks

#38

Post by lucb1e »

spindle wrote: post #35
CWuestefeld wrote: post #12

Earlier quoted context omitted.

ISO is basically a linear gain that's done on the sensor. As long as you aren't blowing out your photo and loosing information, it basically makes not difference if you do it in sensor or later while editing This is true for some cameras, but certainly not all. Many cameras, especially pro or pro-sumer grade, have non-linear ISO. That is, there are ranges for which it behaves linearly, but typically there will be som…

This is a great resource for finding out which ISO ranges various cameras are linear over: https://photonstophotos.net/Charts/RN_e.htm

Taking one of the few recent-ish mainstream phones on this list since the subthread is about smartphone sensors: Samsung Galaxy S7 has an ISO range of 50–800 and basically all the noise values (measured in log2(electrons)) are between 2 and 3. There is a downward trend from 50 to ~300, above that it's all around 2. Other phones have similarly shaped graphs with different absolute values.

That sounds like the opposite of what GP (CWuestefeld) described. Am I misinterpreting the graph?

Lower sounds better to me, so the downward trend on a scale called "Input-referred read noise" sounds like it is tuning the Signal to Noise Ratio (SNR) on the sensor rather than just multiplying the sensor's output value, and it stops doing that above ~300 ISO. GP described that it would be a linear multiplier up until (for many cameras, not specifically smartphones) ~1600 ISO and after that it would be tuning the SNR. Do smartphones behave differently for some reason or am I misunderstanding something?

(It doesn't seem as though the absolute value says anything about the quality by the way, as a 10th gen Apple phone has a much lower value on this "noise" scale than a 12th gen one. The page does remark "raw values are not appropriate for comparing camera models because they are not adjusted for area", so this is probably that.)

Re: Photography for geeks

#40

Post by post_break »

Somewhat related but if anyone is looking to get into photography Fuji is putting out digital cameras that emulate their film stocks. The results are pretty incredible. Also they have manual dials on the top so you're not trying to program a computer to use it. It's like driving a manual transmission vs an automatic.
Post reply on HN