[Des]

If you can shoot in a way that you are always at base ISO, fine. Studio portrait, a lot of landscape photography, sure. But for some types of photography that is just not possible - like wildlife and macro in the field. Shooting wildlife, even with your aperture wide open, to get the kinds of shutter speeds you need is impossible without raising ISO. I often use fill flash, but even a powerful flash won't help much catching a moving subject 30 metres at 1/800th or faster; even with a flash extender, the falloff with HSS is huge. If the light is mediocre, there is no option but to raise the ISO. Same for macro in the field, where you need to push aperture (stacking isn't viable) and subject movement requires a reasonable shutter speed.

[Serkevan]

If you can shoot in a way that you are always at base ISO, fine. Studio portrait, a lot of landscape photography, sure. But for some types of photography that is just not possible - like wildlife and macro in the field. Shooting wildlife, even with your aperture wide open, to get the kinds of shutter speeds you need is impossible without raising ISO. I often use fill flash, but even a powerful flash won't help much catching a moving subject 30 metres at 1/800th or faster; even with a flash extender, the falloff with HSS is huge. If the light is mediocre, there is no option but to raise the ISO. Same for macro in the field, where you need to push aperture (stacking isn't viable) and subject movement requires a reasonable shutter speed.

That's not what GUB is saying; he shoots at base ISO a purposefully underexposed picture, he just lifts the shadows in post.

Let's assume that Sparrow #26 is flying pretty fast and the light is not so strong, while you are on a 2.8 lens.

"Good exposure" is achieved at something like 1/500 shutter for motion freeze, f/2.8 and ISO 1600.

GUB proposes shooting 1/500 and f/2.8, but at ISO 100 - and then going to LR or your program of choice and cranking ISO 4 stops.

Advantage of the method: you will preserve highlights that might be blown out at ISO 1600
Disadvantage of the method: you won't really see whether the image is a good one just by chimping, if it's too dark.

For ISO ranges of 200-800, ISO 100 still lets you get a pretty clear picture, but much more and you will see a bit too much darkness *in my experience*

I have found my compromise by using TAv mode at -2 EV compensation; it preserves highlights very well and I can still see what I'm getting.

[savoche]

I don't understand all this no ISO thing at all. You say put the camera on 100 iso (base) and choose any shutter speed or aperture, shoot any scene, and fix it in post processing? All sounds like rubbish to me.

Not rubbish, just a different way of doing it. BUT it's a valid way only if you have an ISO invariant camera and shoot raw. Trying it with a JPEG file or a Canon 5D would not be a good idea.

That said, I prefer raising the ISO to the "proper" value. I see it mainly as a matter of preference, with both ways having some drawbacks.

[savoche]

Need to check your info. Aperture and shutter speed have nothing at all to do with noise.

Aperture and shutter speed are the two variables that dictate the light levels on the sensor. If they are unnecessarily restrictive then the noise to signal ratio gets unnecessarily increased and further magnified by downstream gain. Noise is totally to do with the two variables.

Yes, noise* and (more interestingly for us) the signal-to-noise ratio are directly linked to the amount of light hitting the sensor. Quadruple the amount of light and the noise only doubles. (Yes, more light means more noise, but also an even stronger signal to average out the noise - resulting in less visible noise.)

* With ISO invariant sensors noise is mainly shot noise. With less efficient electronics noise will be introduced at other points as well.

[GUB]

That's not what GUB is saying; he shoots at base ISO a purposefully underexposed picture, he just lifts the shadows in post.

Let's assume that Sparrow #26 is flying pretty fast and the light is not so strong, while you are on a 2.8 lens.

"Good exposure" is achieved at something like 1/500 shutter for motion freeze, f/2.8 and ISO 1600.

GUB proposes shooting 1/500 and f/2.8, but at ISO 100 - and then going to LR or your program of choice and cranking ISO 4 stops.

Advantage of the method: you will preserve highlights that might be blown out at ISO 1600
Disadvantage of the method: you won't really see whether the image is a good one just by chimping, if it's too dark.

For ISO ranges of 200-800, ISO 100 still lets you get a pretty clear picture, but much more and you will see a bit too much darkness *in my experience*

I have found my compromise by using TAv mode at -2 EV compensation; it preserves highlights very well and I can still see what I'm getting.

Really well presented Serkevan.
One other disadvantage of staying at base iso is it gets difficult to fine tune the base of the curve to the degree needed when it is a lot of stops under. The curves tool becomes a blunt tool. That is is in my developer of choice - Darktable - which also only has 3 stops of EV available.

[beachgardener]

only if you have an ISO invariant camera

Do they exist? If so what brand and model?

---------- Post added 30-01-20 at 08:17 AM ----------

and then going to LR or your program of choice and cranking ISO 4 stops

Do you mean the exposure slider? I don't remember seeing an ISO adjustment in Lightroom.

[Serkevan]

Do you mean the exposure slider? I don't remember seeing an ISO adjustment in Lightroom.

Yes, the exposure slider.

[beachgardener]

If these cameras exist I think someone needs to write some sort of manual on this.


I certainly don't know how to choose an exposure with this method, No ISO, in a given light, what fstop and shutter to produce desired image? And just hope there is enough slider in lightroom.

[stevebrot]

Need to check your info. Aperture and shutter speed have nothing at all to do with noise.

Only if one underexposes or if the subject has significant areas of low value.


Steve

[GUB]

If these cameras exist I think someone needs to write some sort of manual on this.


I certainly don't know how to choose an exposure with this method, No ISO, in a given light, what fstop and shutter to produce desired image? And just hope there is enough slider in lightroom.

Almost the majority of cameras now are near enough to ISOinvariant. Pentax apsc from at least the 16 megapixel days are very Isoinvariant and my K1 as well. There is a bit of a caveat with the new ones with the accerator unit. I know it gives a boost in Dynamic range when it kicks in around ISO400 -- I on't know whether that also brings in noise reduction.
My Q original appears to be reasonably so.
Canon is the main exception.

[GUB]

Only if one underexposes or if the subject has significant areas of low value.


Steve

Correct - and the post of mine that macman was referring to was about tradeoffs. (if you want more dof you will get more noise).

[beachgardener]

@GUB, yes but our cameras have ISO and we still choose our parameters with the exposure triangle eg. in lower light I might choose ISO 400 and then the aperture and shutter to the effect I need.

With an ISO less camera where is the starting point? So just choose a shutter an aperture desired an hope for the best?

[GUB]

With an ISO less camera where is the starting point? So just choose a shutter an aperture desired an hope for the best?

Actually for me that is not far from it. In manual mode saving to raw. And utilising Digital Preview (or chimping if you don't have DP).
Observe your subject and what you want from it.
on that basis choose your shutter and aperture.
Check your histogram for clipping from overexposure or observe the degree of underexposure and start playing the trade-off game.
Of course after you have done this a lot you tend to close in on the ideal combo a lot quicker than in the beginning.
And you are actually concentrating on the core variables that make an image and not adjusting some irrelevant parameter in the camera..
There is absolutely nothing wrong with increasing ISO at this point to make post processing a little easier but you have to bear in mind that you have already dialed in some noise when you observe the histogram.
Given how good noise levels are these days a bit of hit or miss doesn't matter that much with one exception - make sure you are not clipping (overexposing) anything important in the image

[beachgardener]

@GUB, I find his a hard concept to come to terms with.


I use the camera in a traditional way in manual, sometimes with available modes, often with hand held exposure meter. I'm not one for chimping at all. Instead I prefer to choose the correct or as close to correct exposure as I can get for a given scene. Thus less post processing needed as such.
Maybe for landscape I'll give it a go, see how it works, but for most other scenes I want to know where I'm at with correct exposure.
Cameras may evolve to ISO less, but they have to come up with a good way of choosing exposure for the operator, and maybe software will need to develop along with it.

[GUB]

@GUB, I find his a hard concept to come to terms with.


I use the camera in a traditional way in manual, sometimes with available modes, often with hand held exposure meter. I'm not one for chimping at all. Instead I prefer to choose the correct or as close to correct exposure as I can get for a given scene. Thus less post processing needed as such.
Maybe for landscape I'll give it a go, see how it works, but for most other scenes I want to know where I'm at with correct exposure.
Cameras may evolve to ISO less, but they have to come up with a good way of choosing exposure for the operator, and maybe software will need to develop along with it.

Everyone should do things their way.
But now I hope you can see why we question whether the exposure triangle should be taught to noobs.