The beauty of Auto-ISO...

I read a lot of articles about photographers using and swearing by Auto ISO but was wary of using it, because I don't like to go over ISO 400 if I don't have to. Actually, I have been shooting Digital since 2003 and have never used Auto-ISO except with my point and shoot Lumix camera. I thought the whole thing was a gimmick to sell cameras. Due to the this COVID 19 lock down however, I have become a lot more "intimate" with my cameras.

 

So today I decided to try Auto ISO while in Manual Metering mode. I also avoided using Manual Metering mode with digital cameras, because to me it was just too complicated. You had to look through the viewfinder, often squinting, then try to change the aperture and/or shutter speed until(depending on the camera) the (+-) number through the viewfinder read +0 or the arrow was at the center of some type of exposure scale. Most digital cameras use "Live" exposure metering in manual mode, so your readings could change by the second further aggravating the situation. This was way to erratic and non-intuitive for me so I rarely used Manual Metering mode unless when using Flash in ETTL, ITTL, PTTL mode.

 

What I did not realize until today, is that you can set your camera to Auto ISO and by setting the camera to Manual Metering mode you can then use any Aperture/Shutter speed combination and the camera will set the proper ISO value so that your picture is properly exposed ! This opens up a whole new world when it comes to control and creativity ! it reminds me of when I was shooting film and was in total control of how the final image would appear. With today's improved sensors you can go as high as 3200 and still have a workable image, although the lower the ISO the better rule still applies...

Edited June 27, 2020 by hjoseph7

I believe you meant Manual Exposure mode because the Metering Mode would typically be Spot, Center-weighted, or Evaluative (or Matrix) with other options available on many cameras. This is important because the metering mode is generally a vital part of attaining a good exposure. Speaking of exposure, ISO is not a part of that equation, so you have a "good" exposure when you have optimally exposed the image while retaining a desired aperture and shutter speed (i.e., the only two parameters available to you in the camera to control exposure are those two).

 

Since I practically always shoot Raw format, and I often use Auto-ISO on my Nikon cameras (currently a D800), I do have a few thoughts on my approach to how to best utilize that feature. Yes, I generally start out in Manual Exposure mode, and I use Center-weighted metering (set to "Average" on my Nikon cameras), and I set EC (exposure compensation) to zero or sometimes an appropriate negative value to preserve highlights. To put that last setting into context, Auto-ISO is my preferred approach when coming off of base ISO where optimal exposure is a given, and when I am using Center-weighted metering on my D800 (and most other cameras I have used) my default setting for EC is +.7 and sometimes that even goes to +2 though usually a stop from default is close to ideal.

 

One last point about "...the lower the ISO the better rule." As I stated above, it's "the more the exposure the better rule" and ISO is the means we use to compensate for a less than ideal exposure.

Many other 'secrets' are buried in the documentation.:rolleyes:

I normally use auto ISO, for casual shooting it's wonderful, combine auto ISO with auto shutter speed (with a sensible lower limit) and you can just point and shoot.

 

For more serious work, I make a few test shots, then lock in aperture, shutter and ISO, so shooting in full manual, but with the benefit of instant review.

 

For casual shooting though, auto ISO is king, particularly on a camera that allows you to apply exposure compensation to bias the result.

 

As a film only user until 2 years ago, being able to change the ISO at will was a revelation.

 

This post may have been sponsored by fondu and most of a very good bottle of wine.

I usually shoot in Aperture Priority mode (trees and rocks don't move very fast). My Sony has a smart Auto-ISO function where you can set a slow speed limit which varies with the focal length. When you reach that limit, the ISO increases to the right exposure level.

 

When shooting video, ideally you use manual mode for everything. I've yet to find an "ideal" situation. However I prefer to use the Shutter Priority mode (1/60), and let the aperture and ISO vary appropriately. Most of my shooting is indoors, so the aperture is usually wide open, and the ISO typically settles at about 3000.

I use manual exposure and manual ISO. ISO is generally the last resort for me, especially if it means going over 400 or so. Don't get me wrong, I do go up high when the situation warrants and have had fun even playing around with higher ISO settings when I don't "need" it. I've become pretty fast at resetting my exposure controls for what the situation calls for and have fun predicting situations as I'm walking around so my camera will be as ready as it can be. It's just my own personal way of feeling comfortable that I'm learning all I can and able to experiment with various non-traditional exposures that a camera's auto settings might never consider. I know I have missed a good exposure on shots because of that occasionally. To me, the benefits outweigh those risks. I've now lived long enough to learn not to have too many regrets over missed opportunities. Thankfully, I've been lucky enough to have other opportunities still come along, sometimes even better ones than the ones I missed. It also allows for some happy accidents, which are my favorite kind. DUH! Some amazing things happen when I allow for mistakes. So often, today's mistakes are tomorrow's keeper. That's because what seems like a mistake at first might only seem that way because I'm expecting this or that outcome. And, sometimes, the unexpected, unpredicted, and unplanned for outcome is where one rises above cliché and goes beyond what's considered "good" or "the norm."

I use auto-ISO most of the time, with a max limit of 3200, again, most of the time. I was recently thinking about how much simpler film cameras were. Just shutter speed, aperture and focus. I think there was also a meter involved ;-) Digital seems to have dozens of menu pages and is way more complex... until I realized nothing has changed. It's still just light on a sensor, how strong and how long. Everything else is automation and interactions; I just need to be better at remembering how I've got everything set. FWIW, I don't find a bunch of icons on the viewing screen very useful. Just shutter, aperture, ISO and maybe metering mode.

I usually shoot in Aperture Priority mode (trees and rocks don't move very fast). My Sony has a smart Auto-ISO function where you can set a slow speed limit which varies with the focal length. When you reach that limit, the ISO increases to the right exposure level.

 

When shooting video, ideally you use manual mode for everything. I've yet to find an "ideal" situation. However I prefer to use the Shutter Priority mode (1/60), and let the aperture and ISO vary appropriately. Most of my shooting is indoors, so the aperture is usually wide open, and the ISO typically settles at about 3000.

 

I think a lot of newer camera's have a range limiter for auto Iso. I also usually work in Aperture Priority but with manual ISO. From film days I more often then not shoot around 400 ISO anyways and still do, only change ISO when needed to keep a desired Fstop setting and/or shutter speed. Modern digital cameras shoot pretty cleanly at what used to be considered higher ISOs so going higher is often not a problem.

I shoot similarly as Samstevens.

I set the upper limit in my Sony cameras to ISO 25,600. The results are cleaner than any ISO 800 film I used prior to 2003.

I read a lot of articles about photographers using and swearing by Auto ISO but was wary of using it, because I don't like to go over ISO 400 if I don't have to. Actually, I have been shooting Digital since 2003 and have never used Auto-ISO except with my point and shoot Lumix camera. I thought the whole thing was a gimmick to sell cameras. Due to the this COVID 19 lock down however, I have become a lot more "intimate" with my cameras.

 

So today I decided to try Auto ISO while in Manual Metering mode. I also avoided using Manual Metering mode with digital cameras, because to me it was just too complicated. You had to look through the viewfinder, often squinting, then try to change the aperture and/or shutter speed until(depending on the camera) the (+-) number through the viewfinder read +0 or the arrow was at the center of some type of exposure scale. Most digital cameras use "Live" exposure metering in manual mode, so your readings could change by the second further aggravating the situation. This was way to erratic and non-intuitive for me so I rarely used Manual Metering mode unless when using Flash in ETTL, ITTL, PTTL mode.

 

What I did not realize until today, is that you can set your camera to Auto ISO and by setting the camera to Manual Metering mode you can then use any Aperture/Shutter speed combination and the camera will set the proper ISO value so that your picture is properly exposed ! This opens up a whole new world when it comes to control and creativity ! it reminds me of when I was shooting film and was in total control of how the final image would appear. With today's improved sensors you can go as high as 3200 and still have a workable image, although the lower the ISO the better rule still applies...

 

Good Luck to you!

Experiment with using auto ISO with your camera. If it seems to work the way you want, use it. If not, don't. Pretty simple!

I set the upper limit in my Sony cameras to ISO 25,600. The results are cleaner than any ISO 800 film I used prior to 2003.

Imagine you could time travel back to the 1970s, the days of Tri-X and Accufine and grain, and show them useful results at 25,600! I know I would have been impressed.

I use Auto ISO with Aperture Priority mode but would never use it with manual. I do use manual mode very often but whenever I do it's also manual ISO. If you have the impression that when you use manual with auto ISO you're free to set any shutter speed/aperture you want then you're bound for disaster.

I souped Tri-X in Dektol, diluted 1:1, to shoot at ISO 1000 for basketball games. Grain wasn't a consideration. For everything else, I used D-76 diluted 1:1, one-shot at ISO 200. Accufine blurred grain but didn't increase detail. Diluted D-76 produced fine but distinct grain with great edge and shadow detail.

 

The only time I've actually needed 25,600 is back stage with a single open light bulb at one end (for safety). I couldn't see the numbers on the camera dials. There was more light on the darkened house from the stage alone.

 

I remember "the day", but I don't miss it much (except for my callow yourth).

Edited September 28, 2020 by Ed_Ingold

Manual Mode with Auto ISO is a useful tool if you want to control both your aperture and shutter speed, and you also want auto exposure. It is more useful if your camera supports exposure compensation in this mode. You are certainly not in traditional manual mode since your camera's auto exposure system and auto ISO is in full operation with all its inherent strengths and weaknesses.

Just curious why this thread has lurked around for 3 months before being bombarded with 14 responses in two days?

 

That's crazy!

Just curious why this thread has lurked around for 3 months before being bombarded with 14 responses in two days?

 

That's crazy!

Because I didn't know it's was 3 months old. Sorry Joe! However I am kind of curious how much luck the OP has doing what he said. From original post it seems to me he took it in a wrong way.

I tried to unwatch this thread but they keep on commin.

I use Auto ISO with Aperture Priority mode but would never use it with manual. I do use manual mode very often but whenever I do it's also manual ISO. If you have the impression that when you use manual with auto ISO you're free to set any shutter speed/aperture you want then you're bound for disaster.

 

When using Auto-ISO with Manual Exposure mode I watch the ISO displayed in my viewfinder. I have dialed down to zero (as stated in my initial reply to this thread), and that usually affords me some headroom in the Raw files, so when I hit ISO 100 I still have a little room to work with. As for the ISO going "too high," that's just another constraint along with not having enough ability to use a wider aperture or a slower shutter speed.

 

I sometimes do use your approach, but I generally prefer mine. I don't see myself flirting with "disaster" when taking my approach and don't see how taking your approach would be any less of an issue since you end up with a shutter speed that's too slow versus when the light is too low; OTOH, when there's too much light for the selected aperture and the base ISO of your camera then having faster shutter speeds can afford you more room to avoid overexposing.

Interest picked up as the thread evolved from "how to" to "when and why."

If you have the impression that when you use manual with auto ISO you're free to set any shutter speed/aperture you want then you're bound for disaster

Good to know - because that is the ONLY way I shoot these days: M mode, AutoISO ON, matrix metering; exposure correction dialed in as needed. That does give me the freedom to choose shutter speed and aperture freely - AutoISO makes sure I do get a properly exposed shot. No danger there at all - if the ISO goes high, then it's because the circumstances require it and there's absolutely nothing I could do otherwise to keep it low - I either need the fast shutter speed to freeze some motion and the aperture is already maxed out or I need the aperture setting and can't lower the shutter speed any more - they only recourse in either case is have AutoISO raise the ISO to whatever limit I have set. With my current cameras, it's also possible to get out of AutoISO without having to dive into the menu - so when I do need to fix the ISO, it's easy to do.

the only two parameters available to you in the camera to control exposure are those two

I understand what you are trying to say - but there are three parameters that control exposure: shutter speed, aperture and ISO. With film, the latter is fixed - with digital not so much. With the caveat that the higher you set the ISO (or let AutoISO set it), the lower your dynamic range and the higher your noise level. But in many cases, a compromise has to be made and ISO can't stay at base level. You can call that base-level ISO exposure "ideal" - but even at higher ISO, you still get the correct exposure. In most of my shooting, I hardly ever have the luxury of staying at base ISO as it often requires shutter speeds of 1/2000 to 1/3200 on a lens with a maximum aperture of f/5.6; most of the time, the ISO floats somewhere between 400 to 6400, depending on lighting conditions.

Speaking of exposure, ISO is not a part of that equation, so you have a "good" exposure when you have optimally exposed the image while retaining a desired aperture and shutter speed (i.e., the only two parameters available to you in the camera to control exposure are those two).

I understand what you are trying to say - but there are three parameters that control exposure: shutter speed, aperture and ISO.

There is a difference between parameters and controls. There are a number of ways to effect metering which will change your exposure, but to say ISO is one of those is putting the cart in front of the horse. You can change the exposure by changing the EC, and if you are using Auto-ISO the ISO will change accordingly to compensate for the change in exposure. The point I'm trying to make is that if you are shooting at f/5.6, 1/2000s and ISO 400 it isn't the same exposure as shooting at f/5.6, 1/4000s and ISO 800; the latter is half the exposure with double the ISO applied to it.

I understand what you are trying to say - but there are three parameters that control exposure: shutter speed, aperture and ISO.

 

This is a problem because "exposure" is ambiguous. People often mean it to mean the brightness of the image, but that isn't really what it means. Exposure is the amount of light to which the sensor or film is exposed. Increasing ISO simply amplifies the signal created by that exposure (along with noise).

This is a problem because "exposure" is ambiguous.

The point I'm trying to make is that if you are shooting at f/5.6, 1/2000s and ISO 400 it isn't the same exposure as shooting at f/5.6, 1/4000s and ISO 800; the latter is half the exposure with double the ISO applied to it.

Point taken (just fell victim to the ambiguity paddler4 mentions) - increasing ISO does not affect the amount of light that reaches the sensor/film - it just changes its sensitivity to it (film) or amplifies the signal coming from the sensor. But as your example shows, ISO is very much a parameter to take into account for a properly "exposed" photo - even it is not part of the strict definition of "exposure" (*). Or to state it differently, to get a properly exposed image, I need to take the three parameters (shutter speed, aperture and ISO) into account; the two "exposure" parameters (shutter speed and aperture) alone won't do.

 

(*) aperture value ^2/shutter speed = EV (exposure value) = log(base2) ((scene luminance * ISO)/exposure meter calibration constant).

If not "exposure," what would you call the net effect of shutter speed, aperture and ISO? "Brightness" doesn't do it because it similar adjustment factors such as gamma, white balance and saturation.

 

I think "exposure" is sufficient to describe the combined effects of the amount of light (integrated) and sensitivity to that light. Unless we resort to Heinlein-like word invention (i.e., "grok"), we digress into sophistry.