The Exposure Triangle Is Misleading And Unnecessary.

what if your using a nikon z9 that doesnt have a shutter or any other camera for that matter using electronic shutter. 😎

Simply consider exposure and ISO independently. Make every effort to maximize the exposure (Light+Aperture+SS) always satisfying any DOF, and motion blur requirements, and then consider ISO.

Whether your shooting full manual or semi-Auto with exposure compensation, once exposure is dealt with, you will then need to decide how much ISO is needed to get the job done…

For jpeg shooters, if there isn’t enough light to fully saturate the sensor at base ISO, it’s going to be increasing the ISO value to achieve the desired image brightness in-camera without clipping any important highlight detail. There are also some other options to consider - DR modes etc., but those are best left for a separate discussion.

For raw shooters, it could be much the same thing, but as most sensors are largely “ISO invariant” these days, you also have the option (for numerous reasons that we can discuss separately) of deferring some, or all, of the in-camera “brightening” (for lack of a better word) that the ISO setting represents, and applying (again, some or all) of any necessary “brightening” in post instead.

What on earth are you wafffling on about?? First you say it doesn't have a shutter, then you say it has an electronic shutter 😀 I don't believe your claim you are a professional photographer when you post waffling questions like that.

Every beginner I have come across so far has been able to understand that the concept and purpose of a camera's shutter is the same whether it is mechanical or electronic 😄

You asking that question indicates to me you might be the first beginner I have come across who doesn't understand that 😃

just came back from a camera club meeting and still trying to drain the energy off, full of conflict, the club is just going backwards atm.

I understand reasons for choosing aperture and shutter speed. Could you please explain how you arrived at Auto ISO limited to 1600 and why -1 EC? Is this specifically for events or for everything? How are you metering?

SNR in raw from cameras I use currently don't benefit from setting ISO higher.

Preserving highlights, under-ISO is better than under-exposure, SNR-wise.

Pre-metering, spot-meter from important highlights, centre-weighted, depending on the situation.

Do you think a wedding photographer who takes shots like that should be paid? I don’t think it’s a professional quality photograph.

I disagree with the premise of your question.

If you submit a landscape into a contest and the judge says there’s a distracting tree branch in the image… it doesn’t matter that the tree branch was there when you took the shot. The photograph, the result, that is what matters.

Yes, if it’s you daughter’s guitar recital and they will only let you stay in your seat and you can’t use a long lens so forth, you do the best you can, and you have the memory.

I’ve shot a lot of concerts, for years, and I’ve run into many limitations. But the client doesn’t care. The viewer doesn’t care. The photo stands alone. And that photo has a few problems, unfortunately. The light hitting her face is pretty good… that’s the good part. But the mic covers her face and focus appears to be on the mic and not her face. I think you could have cropped in a lot more. I know… it sucks to get criticism. I can’t stand being criticized. I’m not trying to put you down; I’m trying to help you get a better shot the next time. Get way closer, keep the screen and beeps off so no-one’s distracted, focus on the eyes, pay close attention to how the light hits the face, include both hands and the guitar, wait until she either approaches or backs off from the mic. The light is best at the mic so you want that instant when they approach or back off.

The GFX 50S stops applying gain to the numbers in the raw file image after ISO 1250. The GFX100s keeps on increasing the numbers as you turn the ISO dial up. Both cameras are ISOless above ISO 1250. I know because I've measured the input-referred read noise vs ISO for both cameras. I've also looked at the histograms of dark-field images with varying ISO settings.

How does it affect my photography? I have no qualms about using the ISO settings above 1250 on the GFX 50S. I don't use those settings at all on the GFX 100S.

The exposure triangle does not exist. When people use the term exposure triangle to help new photographers, they are actually describing an image brightness triangle. The problem is conflating an aesthetically useful, perceived image brightness with an image that has the highest practical signal-to-noise ratio. Here practical refers to minimizing loss of resolution caused by camera or subject motion and, or an effect lens DOF.

Unfortunately, image brightness has little to do with optimizing technical image quality (a.k.a. data information capacity). Data information capacity is a function of the system resolution and raw file SNR. Camera ISO setting has no affect on resolution (unless the camera supports pixel binning). But an ill-chosen camera ISO setting will result in an needlessly low SNR.

With respect and thanks to all the expert contributions in this thread, it's now way more than the 90 posts I started at, and the beginners thread has also been summoned yet, despite reading all the answers and consulting that beginners thread, I find my self even more confused that before we started. I'm 60 years old and started photography aged 13, successfully operated my own B&W darkroom for D&P, used the Zone system, processed E6 slidefilm, started digital in 1999, and definitely don't consider myself a beginner. However, a lot of conceptual baggage comes with all that which may block the path to understanding. And what I mainly want to understand is what is the purpose of the ISO dial and how should I use it for everyday photography. The engineering stuff is a bonus.

I'll summarise my conceptual starting point:

1. Back in the film days we were taught that in order to expose a film adequately in camera, we needed to consider the ambient light level, the film speed, the aperture and the shutter speed. Let's assume film speed is fixed (ignoring pushing etc), that meant we dialed the speed rating of our film into our light meters, pointed at something approx middle grey and got a reading which suggested different aperture/combinations that would yield a passable average exposure. Film speed was fixed, not a variable, unless you were AA processing individual sheet film.

2. Films of different speeds were available, it was important to enter the correct speed into our meters (whether manufacturer's rating or our own EI rating)

3. The exposure triangle idea was promoted to remind people that the exposure your meter recommended would be affected by the chosen shutter speed, aperture and film speed. All 3 variables were important to a correct light meter exposure suggestion. Conclusion 1: in those days, the exposure triangle concept seemed a reasonable didactic concept because film speed changed with different films.

4. With the advent of digital, things appeared to change. Digital cameras have this dial marked ISO. It appears to change the sensor sensitivity on the fly, acting as if you could magically swap out the sensor from shot to shot. Now, when considering light meter readings, film speed was no longer set once and forget, but could be reset for every shot. Conclusion 2: Voila! the exposure triangle is even more vital than before.

5. Then we learnt that conclusion 2 was bunk, because it is not possible to change the sensitivity of the sensor. Conclusion 3: Digital cameras are forever locked into to using a single film speed, the ISO dial does not change film speed! We still however need to set some kind of film speed into our meters, so the exposure triangle is still useful in the limited sense of Conclusion 1 (base ISO varies between cameras)

Having learned one thing with film, then another with digital, then having that declared null and void, where does that leave us?

• If the ISO dial can't increase the sensitivity of the sensor akin to swapping in a faster film, what does it do that is useful photographically?

• Am I better off leaving it at base ISO, forgetting about that dial, considering my sensor as one film speed only and underexposing 5 stops or should I raise the ISO when it's dark to persuade my camera to use a fast enough shutter speed to avoid ruinous camera shake ?

• Why do cameras even have an ISO dial?

On the surface, this whole issue seemed incredibly straight forward and simple Yet it clearly isn't and generates much debate, confusion and misinformation.

At this point of time, having read all this stuff, I now find myself in the position of having no idea what the ISO dial is for and when to use it, which after 47 years of using a camera as a serious amateur is a quite sad situation. But, painful as it is to unlearn long believed stuff, if that is what we need to do, that is what we need to do.

It would be helpful to me to have a written down simplified rule of thumb explanation (that doesn't go deep into engineering and philosophy or need to be 100% technically accurate. Interesting as technical accuracy is, when a cheetah is sprinting past at high speed, you really need an instantaneous rule of thumb to guide your choice of settings in the milliseconds you have to decide)...

Thanks

Dave

I don't know about that. Perhaps a different name was used, but the concept definitely existed in the 1970s. The exact name doesn't really matter.

I don't think it is possible to do that and have it apply to every camera made.

Here's what it looks like for one camera:

blog.kasson.com/gfx-100/fuji-gfx-100s-exposure-strategy/

David,
Forget about the sensor. What matters are the camera and the photograph.

The effect of the ISO setting with JPEG images is much stronger than with RAW. Some cameras are “ISO Invariant.” As I understand, this means that you can shoot the same exposure at multiple ISO settings from 100 to 56,000, and the RAW image will be the same, and you can adjust brightness any of those photos with your RAW editor and get the same result.

My Canons are not like that. I tested them. The ISO setting definitely affects the RAW files. Is that because of the way the sensor works, or because of firmware inside the camera? Guess what? It doesn’t actually matter, does it? If I’m going to reduce my shutter speed and keep aperture constant, I need to increase the ISO setting. So that three-sided shape dynamic is there, no matter how much people dislike the expression :-)