-
Welcome to the new forums! Please read this first. For known issues we are working to resolve, click here.
Manual iso
- Thread starter 4dampadac
- Start date
Auto ISO could result in less physical exposure (aperture diameter/time). With manual ISO I have control over the real exposure.
ISO seems like a weird setting to use to control exposure. I control aperture and shutter speed using the aperture and shutter speed settings, myself
- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
I use either base ISO or auto ISO. When I need higher than base, I shoot Auto ISO In M. But if there's plenty of light, I switch to base ISO and A or S mode.
- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
Basically the same as doing anything manually; auto-anything may sometimes make different choices than what you expect or prefer.
Whether that is actually a problem with your camera, your shooting circumstances and preferences is probably best found out by just trying it out. You may find out that it works perfectly for you, or perhaps identify some specific circumstances where you'll rather set the ISO manually, or decide that manual approach works the best for you.
Last edited:
sportyaccordy
Forum Pro
To create the illusion of full control. Bragging rights
I use manual mode because it's the easiest way for me to control how my pictures turn out, including how bright or dark they are. Using auto ISO defeats the purpose of using manual for me because it then gives control over image brightness back to the camera or forces me to use extra steps like exposure compensation, which I then need to remember to turn off or re-adjust for the next shot.
Also, with my particular cameras (older DSLR's and tiny-sensored compacts), there is not a broad range of ISO's I want to use. I test them upon purchase to see which ISO setting is most pleasing to me (often but not always the base ISO setting), then just leave it alone. With my cameras, even a one-stop ISO change can affect not only noise but produces visible changes in resolution, color balance, and saturation, too. I find these differences very off-putting when trying to enjoy a "slideshow" of images on my computer or television screen.
If I do choose to use an auto exposure mode, my preference is aperture-preferred with manual ISO. For most of the pictures I take, shutter speed is less critical than either aperture or ISO.
I think the responders point was that with auto ISO, if you’re not paying attention, you might underexpose a picture unintentionally because ISO will compensate and increase to an appropriate image lightness when you could have just as easily changed the shutter speed or aperture assuming you have headroom to spare.ISO seems like a weird setting to use to control exposure. I control aperture and shutter speed using the aperture and shutter speed settings, myself
- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
Maybe pros don’t make mistakes, but I’ve certainly reviewed pictures and surprised myself at ISO 6400 with a much faster shutter speed than needed.
He did say "manual ISO in manual mode" ... so whether you're using manual ISO or auto ISO, you're controlling aperture and shutter speed. Personally, I find it easier to ensure I'm maximizing exposure by setting the shutter speed and aperture to do so (i.e. as slow as I'm willing to go and as wide open as I'm willing to go) and then let the camera calculate the ISO ... that's how some photographers use it. Not everyone may prefer to work that way, but there's no reason it should result in less exposure. Certainly, you have to pay every bit as much attention shooting manual ISO in M mode.I think the responders point was that with auto ISO, if you’re not paying attention, you might underexpose a picture unintentionally because ISO will compensate and increase to an appropriate image lightness when you could have just as easily changed the shutter speed or aperture assuming you have headroom to spare.ISO seems like a weird setting to use to control exposure. I control aperture and shutter speed using the aperture and shutter speed settings, myself
- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
I don't see how I'd make that mistake with Auto ISO in M. I use it when shooting action or shooting in low light (and know the ISO will be higher than base) ... and then I choose f-stop and shutter speed to put as much light on the sensor as possible. I wouldn't have a faster shutter speed than necessary because I choose it to be just as fast as I need. Then the ISO is what it is. If it's 1600, great; if it's 6400, oh well. It's whatever it needed to be.
(Note: on my camera, I do see the calculated ISO on a half press, so if I chose a shutter speed that's just adequate, but it turns out the lighting isn't as bad as I though, I might go for a faster shutter speed instead of maximizing exposure ... and conversely, if the ISO is really high, I might give up on trying to freeze action and go for intentional motion blur instead).
- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
Just responding to why someone might use manual ISO in manual. Not passing judgment one way or the other on what is right or wrong. If you don’t make mistakes in that area - then Auto is perfect. No worries.
More than one way to skin a cat, as they say. Although I’ve never tried.
The biggest reason I find to use "full manual" is when setting exposure based on something other than the camera's built in meter. External meter, guidelines, etc.
- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
Not really. The built in meter is a nice starting point. From there you can compensate if you know the camera.
BertIverson
Veteran Member
I use M exposure and manual ISO only when shooting flash. I set base ISO and use TTL flash. This forces the flash to output maximum light. I set shutter speed and f stop manually. This will often yield insufficient brightness but I always shoot RAW and can brighten in PP. (often using graduated filters in LightRoom to lighten the background or darken the foreground)
my 0.02
Bert
Last edited:
If you want to set your exposure based on an external meter, based on guidelines like "sunny f16", based on experience shooting lightning or fireflies, when shooting studio strobes, etc. then that's a good reason to shoot full M. (You may choose to try it with the built in meter, but those are situations where a lot of photographers won't bother with the meter and at that point, full M makes sense).
But in most situations, I am using the built in meter and then I find no reason to use full M. Auto ISO in M or base ISO in A or S with exposure compensation as needed gives me full control.
- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
In the studio, shutter speed is determined by the camera's max sync speed (and a little extra headroom for studio flash sync), aperture is determined by the DOF I want, ISO is set to base for maximum DR, and brightness is set on the strobes.
Auto ISO would force the ISO up, clipping the highlights.
Auto ISO would force the ISO up, clipping the highlights.
Last edited:
ericbowles
Veteran Member
Auto ISO is a semi-automated mode - just like Aperture or Shutter priority. If the exposure changes, these semi-automated modes are terrific at quickly correcting exposure on the fly. But they use metering modes to decide how the exposure should be calculated. Depending on your scene, your exposure could change even though light on the subject has not changed.
But if the light on the subject is constant, you don't want your exposure to change. That means you want a fixed aperture, a fixed shutter speed, and a fixed ISO. Then regardless of composition, the ISO and resulting image won't change.
Think about a bird that flies across a landscape. Matrix and Center weighted metering consider the background. It starts out with tan grasses in the background, then has dark green trees as the background, and finally has a light blue sky with puffy white clouds. If I have the subject correctly exposed - and I can use a variation of the Sunny 16 rule - light on the subject is constant. But with any auto mode, the exposure changes as the background changes. I could shoot wildlife in the same scene for an hour without ever touching the aperture, shutter, and ISO controls.
The same is true for lots of situations. I meter for the face of a subject. I don't want clothing or background lighting to change my exposure - or force me into using exposure compensation to offset those changes. Just give me a fixed ISO if light is constant.
If the light is constant - the correct exposure is constant.
With my cameras if I want to be in full control of the result and use manual settings, there would be no choice to use auto iso. I would be giving automatic control back to the camera. Any time I give the camera the ok to choose iso, aperture, and/or shutter speed, it's the boss and typically does a fine job. But on the occasions that I want to be in control and make my own mistakes it's gonna be all or nothing,
When you're shooting based on the camera's meter and you choose two of three settings, the third one is calculated. It has to be one value. You're not giving control to the camera; you're letting it do a simple calculation.
These modes:
- Auto ISO in M
- S mode with manual ISO
- A mode with manual ISO
all give you full control over settings. You can still choose metering mode and use exposure compensation and AEL to control metering. The only thing you can't do is set an exposure that's unrelated to the meter reading (or that deviates from it by more than 3 stops or whatever the exposure compensation dial allows).
- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
ericbowles
Veteran Member
It's exposure compensation that I try to avoid by using Manual with a fixed ISO. If light on the subject is constant, why would I want to have to use Exposure Comp to offset metering changes that are based on the background? The whole point is to meter once, get the correct exposure, and then maintain those settings without changes.
If light is changing on the subject - or your subject is changing and they are in different light, that's a different story and might be a reason to use some semi-automated settings.
Why am I not giving control to the camera if I let it pick one of the three settings? It will have control of that one instead of me having control of it. ????
Similar threads
Keyboard shortcuts
- f
- Forum