Manual exposure + auto ISO

[rpcrowe]

Lately, I have been doing a lot of my shooting using the camera in manual exposure mode + auto ISO. This allows me to select what I deem as the best shutter speed + best f/stop for my images.

I have been shooting long enough to pretty well know what shutter speed and f/stop would be most appropriate for my images. I have the advantages of manual exposure selection with the advantages of semi automatic exposure control.

I began shooting in this fashion with my Canon 7D Mark-2 and have continued with the Sony A7iii. The Sony A7iii has excellent high ISO capabilities so I don't normally need to worry about the ISO I am using. However, I can limit the extent of the ISO if desired.

With my Tamron 28-75mm f/2.8 lens and the Sony A7iii camera, if I select 1/250 second at f/8, this is an ideal compromise for subjects that are not moving particularly fast in bright conditions. This includes people walking as well as people and animals standing still. The shutter speed/aperture combination will result in an ISO of between 200 and 640 depending on the brightness of my subject. That ISO range is well within the capabilities of the A7ii to achieve excellent image quality.

If I need to shoot at a faster shutter speed, I can select that and if I want a wider aperture for DOF selection or a smaller aperture for a wider DOF, I can also select that.

If I notice that the image is a bit dark or light, I can use a + or - image compensation (which will impact the ISO but, not the shutter speed or aperture)...

I like the dial setup of the 7iii since shutter speed, aperture and exposure compensation dials are very conveniently located close to the shutter button and I can adjust those parameters using my thumb or index finger of my right hand. My muscle memory has been trained to easily adjust the parameters.

This is no for everyone with all different camera/lens combinations. There are some cameras that may not be convenient to use in his fashion but the setup is great with my A7iii and only slightly less so with my A6600 (because of the manner in which I select shutter speed and f/stop)...

[billtils]

Enjoyed reading this Richard. My experiences have been less positive, with too many shots coming up with unacceptable high ISOs, but as you say, that in itself is not a reason to discard the approach. However we set the controls (other that some varient of "Auto") we are at the mercy of the exposure triangle where we can enter our preferred settings in any two and either accept what the camera throws up the third, or tweak more than one.

I suspect the "best" depends on personal preferences, optimum settings for our favoured genres, and of course, how in control we are in regard to the available light.

For myself, I nearly always shoot in Aperture priority, and set aperture and shutter speed to suit the circumstances then see where the ISO pops up. If I don't like what I see, then a compromise of sorts is put in place.

I can best sum up with "Manuals are for reading" ... and shooting in manual violates the KISS principle, but we all have our preferred approaches and in (pretty well) all instances the best approach is the one that works best for the photographer in question.

[russellsnr]

Hi, I try to manual mode with Auto ISO on my 7D MK II but only if the light is not playing the game however with the 7D MK II there lies what I think is a big dissapointment, the ISO range before noise kicks in, I set mine to a max of 1600 ISO but that is only now because I have the Topaz Denoise AI software before that it was 800 ISO max. When we get back to the UK the 7D MK II is out the door for a 5D MK IV as from what I am reading it is a far better camera as far as ISO and noise go. Russ.

[MrB]

I get the impression that a number of Pentax users like this method of image capture, and it is actually present as an option on the Mode Dial of a Pentax DSLR - labelled TAv Mode.

Philip

[Manfred M]

I have used that mode from time to time when the lighting changes rapidly, for instance events and sometimes street photography.

That being said, I continue a practice I've used since my film days; using the lowest ISO I can for a given situation as that will give the best image quality. That means I generally shoot as ISO 64 for landscapes and in studio work. I will crank up the ISO to ensure the aperture and shutter speed will give me strong images in other cases.

For 99% of my work, I will select the ISO before I take my first shot and generally stick with that decision.

[DanK]

My practice is the same as Manfred's. I use auto-ISO rarely, and only when there isn't time to think and reset the camera. E.g., I photographed a play in a poorly lit room, and flash was not allowed. The lighting was quite inconsistent, and I didn't have time to change settings in response because the actors were moving. In that situation, I use manual mode and auto ISO. However, this ine of my only serious dissatisfactions with my Canon 5D III: it does not allow EC with auto-ISO. Since ETTR is particularly important when you get to high ISO values, this is a substantial problem. Newer Canons, I gather, do provide for EC with auto-ISO.

[rpcrowe]

I wan't totally happy with this system using either my Canon 7D2 or 6D2 (which are the most modern Canon cameras that I have used). The higher ISO levels did not generally produce the quality that I wished for.

I have not done head to head testing but, I suspect that the Sony A7iii generally produces better quality at higher ISO levels.

While, I generally use this system when shooting in bright to moderate light... I am a bit more careful of my ISO when shooting in darker conditions...

I also don't use this system when I shoot non moving subjects while the camera is tripod mounted. I then try to use the lowest ISO possible in conjunction with aperture priority and let my shutter speed be the variable...

[pschlute]

I use Pentax cameras and as mentioned above this mode is given it's own designation on the mode dial as TAv.

I use this when shooting action pictures of my dogs. I set the shutter speed appropriate for the lens in use (minimum 1/FL), and an aperture that will give me the required DOF. I am well aware that if they run into a dark area the ISO may be too high for a great picture. But that is no worse (in fact it is better) than a blurry one or one lacking sufficient DOF. There is no escaping the exposure triangle.

[rpcrowe]

There is, as Peter states, no escaping the exposure triangle. What does impact the triangle however are two parameters:

First is how much noise you will accept in your image. I expect (but cannot verify) that older photographers who cut their teeth on grainy and slow film emulsions "might" be more forgiving in the aspect of noise. IMO, a sharp noisy image is better than a fuzzy image without noise due to a slow shutter speed. Correct exposure also helps in reducing noise.

Second is how your hardware (such as camera sensor) and software (such as noise reduction) will mitigate the noise to a point in which it can be accepted.

The photographer should know what he/she considers the limits of the equipment mitigated by whatever noise reduction software the photographer has available....

I am quite comfortable using an ISO as high as 3200 with my Sony A6400 and using the NIK Dfine 2 noise reduction software...



And... I will not hesitate using ISO 6400 with my A7iii.

This type of ISO was totally unheard of when I began in photography when an ASA (forerunner of ISO) of 125 was considered high speed as in Kodak High Speed XX film...

If I have to exceed the 3200/6400 ceiling to get the image, I will do so!

[Manfred M]

Richard - I cut my teeth on film as well and sometimes chose a grainy film or processed the film to give me enhanced grain in the negative. Grain can be very effective.

Digital noise does not look at all like grain and I find that it can be distracting and if I can't bring the noise under control in post, I will discard a noisy image. Grain was evenly distributed throughout the film emulsion, whereas noise tend to be in the dark shadow areas and not so much in the highlights.

[tclune]

I always use manual mode with auto-iso when I am birding or shooting wildlife with my long lens. I have the old Sigma 150-500 f/5-6.3 lens. It is not bad enough to replace (especially for someone of my middling photography skills), but it is on the soft side if you shoot it wide open, so I stop the aperture down a couple of clicks. And my mediocre technique calls for me to use a monopod (I am unwilling to lug a tripod into the field) and shutter speed of at least 1/800s to keep from having noticeable motion artifacts. So I know the aperture and shutter speed that I will need in order avoid mechanically ruining the shot. So I let the iso float. I'm not saying that this is the right approach generally, but it suits my equipment, skills, and style.

[ETA: I shoot with a Nikon D5200.]

[rpcrowe]

I also use this method when the shutter speed and aperture needed is the primary concern. Like a very fast shutter speed stopped down one or two stops to get the bast quality as well as a decent DOF rather than the thinner DOF resulting from shooting wide open.

Sometimes, I get quite cavalier about using a high ISO when I shoot with the A7iii. This shot was done at 1/60 second at f/8 using ISO 10,000. It is, IMO, quite usable.



I would never have attempted using an ISO this high with my Canon 6D Mark-2 which was the latest full-frame Canon DSLR I used...

[MrB]

Sometimes, I get quite cavalier about using a high ISO.....

Similarly I tend not to be too concerned about ISO - this was a hand-held shot in window lighting, taken at ISO 6400 (f=35mm, f/4, 1/50s, -1EV)
:



[Pentax KP]

Philip

[DanK]

Richard and Philip,

Did you use noise reduction on these photos?

As I'll show, displaying at this small size isn't a good test.

Each generation of sensor is better than the previous in terms of minimizing noise from using a high ISO. My current camera (Canon 5D III) is one generation out of date, soon to be two generations. How much noise I get with higher ISOs depends on the exposure level: the farther to the right it is, and the less distance it extends to the less, the less noise (which is just math: less signal and constant noise as you go to darker regions).

Here are a couple of test shots I posted a few years ago that show the impact of exposure, using a 7D generation 1 -- an old camera that's quite noisy when shot at high ISO. Both were shot at ISO 3200, and I used no noise reduction. The first was shot with optimal exposure and is clean, even in the lighbox:



The second was shot 3 stops lower and boosted to the same brightness in post:



The difference is small when shown at this size, but if you look in the lightbox, it's quite clear: the underexposed image is clearly noisy. Displaying at a small size, as we have in this thread, lessens the impact of both noise and the lack of sharpness caused by noise reduction. In the example I posted, if you looked only at the originals in the post, you would incorrectly conclude that 7D has minimal noise even when shot at 3200 and underexposed by 3 stops.

All that said, if you replicated exactly this with your A7iii, Richard, my guess is the second shot would be a lot cleaner than this one.

[Manfred M]

While people tend to concentrate on digital noise at higher ISO values, we should also not forget that there are other factors that suffer as we push up the ISO setting.

We also lose dynamic range, colour sensitivity and tonal range.