Auto ISO (Page 5): Thanks. It isn't clear to me why constant neutralization of the built-in tendency for cameras to seek to produce 18% grey to ensure white is camera dependent. And if...

gessman Loc: Colorado

CHG_CANON wrote:

Except for not being so far to the right of the 0-mark, that's the process described above in my earlier post. Every model / brand is a bit different on where / how far to the right you can default. Most are fine a +0.7, others +1. Your photographer has found for their camera's RAW, +1.3 is best for their camera and their software recovery.

Thanks. It isn't clear to me why constant neutralization of the built-in tendency for cameras to seek to produce 18% grey to ensure white is camera dependent. And if all cameras do seek to produce 18% grey, or as some contend, closer to 13% grey, why, barring a defect in individual cameras, would the constant EC setting of +1.3 need to vary from camera to camera?

CHG_CANON Loc: the Windy City

gessman wrote:

Thanks. It isn't clear to me why constant neutralization of the built-in tendency for cameras to seek to produce 18% grey to ensure white is camera dependent. And if all cameras do seek to produce 18% grey, or as some contend, closer to 13% grey, why, barring a defect in individual cameras, would the constant EC setting of +1.3 need to vary from camera to camera?

It probably has to do with the brand's own secret sauce for amplifying their sensor signal to a given ISO. Every camera has a 'base ISO' that all images are actually captured at, typically ISO-100. To get to say ISO-500, the signal is amplified (brightened) to the corresponding ISO. There exists subtle differences in how this amplification works, as well as individual photographer needs and skill, where one might see 'can' while others see 'should' for using +1.3 vs +1 vs +0.7.

For my EOS DSLRs, I strive for +1 to +1.3 over the 0-mark. I've found this consistent for EOS models and their RAW files, both full-frame and cropped. Although I can recover highlights from Sony RAW, I've found the edit effort is more efficient if I hold the EC between +0.3 and +0.7, and only for specific shaded situations do the files benefit from pushing the EC to +1.

BebuLamar

gessman wrote:

Thanks. It isn't clear to me why constant neutralization of the built-in tendency for cameras to seek to produce 18% grey to ensure white is camera dependent. And if all cameras do seek to produce 18% grey, or as some contend, closer to 13% grey, why, barring a defect in individual cameras, would the constant EC setting of +1.3 need to vary from camera to camera?

It should vary from camera to camera.

olemikey Loc: 6 mile creek, Spacecoast Florida

Auto ISO works for me (situational), it is a great additional tool.... I think it important to limit the high end to whatever you consider to be an acceptable ISO maximum you can use based on your own allowable noise limits and editing capabilities in final product.

gessman Loc: Colorado

CHG_CANON and BebuLamar

Your comments make me want to ask why then, would not each camera require a different shade of grey card to ensure we get white but, but, we only have one grey card? What am I missing here? Asking for a friend...

Mac Loc: Pittsburgh, Philadelphia now Hernando Co. Fl.

CHG_CANON wrote:

An ideal camera supports Auto ISO in Manual with E... (show quote)

Seriously. I wasn’t aware of that and it is very interesting. I will play around with it, but it sounds like a great option.

CHG_CANON Loc: the Windy City

gessman wrote:

CHG_CANON and BebuLamar

Your comments make me want to ask why then, would not each camera require a different shade of grey card to ensure we get white but, but, we only have one grey card? What am I missing here?

The grey card is a reference, not a final judgement. The ISO standard is a standard digital cameras have to be compliant with (to be ISO compliant and express "ISO" in the results), but there are no rules on how to get there. As you noted earlier, this bias toward some % grey also is open to interpretation.

The photographer also has their own eye on what is important. Do they want 'white' in their image? Do they want 'black' in their image? How do they want to adjust the white balance? There is no one 'correct' answer. I tend to use LR to tell me where there are any pure white pixels in the final edit (as well as pure black) without any reference to a grey card. This is a technique learned from a school of LR users / editors that use this approach. It's a technique for how to undo this grey-bias, but also ties into ETTR for noise control. Even with the same software tool, many other editors / photographers approach color and tone and WB completely different.

DaveyDitzer Loc: Western PA

John from gpwmi wrote:

Often used in M-mode where the photographer wants to control both the aperture and the shutter speed. Auto ISO will then balance the exposure triangle for the best shot. Max limits can be set so it doesn't go into the high noise region of ISO.

I use this same approach and then use exposure comp. if I want changes or lower ISO

BebuLamar

gessman wrote:

CHG_CANON and BebuLamar

Your comments make me want to ask why then, would not each camera require a different shade of grey card to ensure we get white but, but, we only have one grey card? What am I missing here? Asking for a friend...

While the ISO standard is very flexible and allows each manufacturers to define theirs differently I do find that the shade of gray they used is about 18% and the jpeg are about the same. The main differences are in the raw, some allows for more headroom in the raw than others. The amount of headroom is different from a 12 bit and 14 bit raw. And today we have camera with 16 bit raw.

PhotosBySteve

The only time I use Auto ISO is when shooting wildlife or birding

kcooke Loc: Alabama

dpullum wrote:

On Page 1, KCooke said: "I Manually set shutter, speed, and f stop using auto iso for action or moving wildlife. Otherwise manual and starting ISO of 50 or 100. Not saying it’s right it’s just what I do and works for me."

Yes, KCooke, correct. Exposure is a 3 point Teeter-Totter, chose two and to balance the third one changes automatically. In this post, the ISO will adjust automatically if the aperture and speed are set.

Indeed. On auto Iso I set my max iso at 6400 usually

HRBIEL Loc: Rapid City, SD

Diving Osprey present the biggest exposure challenge for me. To get adequate sharpness on the “splash”, I either use S mode setting the speed to at least 1250 or 1600 sec, or M using the same shutter speed and opening the lens up all the way. ISO set to auto in either case. Shooting on Nikon D500, D850, or Z6ii. Anybody have a better suggestion?

PHRubin Loc: Nashville TN USA

I often use it when I want specific aperture and shutter speed settings. I also use Exposure Compensation (EC) with it, as required, for best results.

philo Loc: philo, ca

for what i do noise has never been a problem. I print 8x11 prints and once in a while 13x16. so auto iso and auto wp works for me.

jayluber Loc: Phoenix, AZ

BebuLamar wrote:

You didn't say which mode you used. P, S, A or M?

He said Aperture Mode...