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Shooting Tips

Why Auto-ISO + Manual Mode Is the Best Auto Exposure Mode

By Anthony Thurston on December 20th 2014

Many of you have and do use Shutter Priority or Aperture Priority on a consistent basis. But what if I told you that Auto ISO, when combined with Manual Mode, is actually the best auto-exposure mode there is?

[Reminder: Learn More About ISO in Photography 101]

Now, before you all jump down my throat, yes, Shutter and Aperture priority can be used to great effect. But my problem with them lies with the fact that I have to pick between my creative aperture choice (Aperture Priority), or motion control (Shutter Priority).

SAM_0051As a sports and wildlife enthusiast, this is not ideal. I want to be able to stop the motion, AND get the creative aperture I want. This is why I choose to use Auto-ISO in conjunction with Manual Mode to give me control over the creative look of my image.

There is a big stigma in the industry regarding auto-ISO, and I think that a lot of this has to do with how bad noise could get at higher ISO numbers in the past. The reality is that most newer bodies are pretty good with noise up to ISO 3200 or 6400, which in many situations, is plenty. The other part to this stigma, in my mind, is that ‘auto’ is used in the function name. People, especially Pros and Semi-Pros, get scared with that word in regards to their camera exposure.

exposure triangle

But let’s break it down. The exposure triangle consists of the shutter speed, aperture, and ISO. Shutter and Aperture Priority modes allow you to set the shutter/aperture with a set ISO, while Auto ISO with Manual Mode allows you to set both the shutter speed AND aperture and lets the camera set the ISO to make a correct exposure (within ISO limits that you choose).

Sure, the camera may not always get the ISO exactly right, but just as with Shutter priority or Aperture Priority, it is usually pretty close. Enough so that a quick turn of the exposure compensation dial on the camera, or a small pull of the exposure slider in Lightroom results in a perfect look. The difference being, if aperture or shutter priority screws up, you can end up with blurred motion or an F/16 image with no depth of field. If the auto-ISO screws up, and you have your limits set to an ISO number you are comfortable with as far as noise goes, at worse your image is a little dark or a little bright – but usually salvageable in post-production while maintaining the creative look for the image that you originally intended.


You can’t fix motion blur in post production, and adding depth of field is more trouble than it’s worth, in most cases, if you want it to look real. So, if Shutter/Aperture priority screws up, it can still cost you the image you meant to take. This is why I always prefer auto-ISO with manual mode if I am going to use auto-exposure at all.

Steve Perry Manual Mode with Auto ISO

We have featured Steve Perry’s videos many times before for their great tips and tricks. This week Steve released a new video about this exact topic, and while it’s not as quick and to the point as his normal videos, it is a great resource for anyone interested in learning more about using manual mode with auto-ISO.

What are your thoughts on this taboo exposure mode? Did you know that you could do this? Would/Do you use manual mode in combination with Auto-ISO? Leave a comment below and let us know what you think!

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Anthony Thurston is a photographer based in the Salem, Oregon area specializing in Boudoir. He recently started a new project, Fiercely Boudoir to help support the growing boudoir community. Find him over on Instagram. You may also connect with him via Email.

Q&A Discussions

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  1. Alastair Archibald

    I have been using this setting a lot on my Sony A7RII* since first watching this video. I find it very convenient because with most shots, you’re concerned primarily with DoF and motion. I have aperture on the front dial and shutter on the rear, and so I can keep my eye on the finder and compose on the fly.

    I can take care of artsy brightness and darkness tricks by using the exposure compensation wheel, which gives me +/- 3  stops. But in most cases, I don’t need to mess with the exposure.

    *My least favourite aspect of Sony cameras is the menu structure, and inn any case the only Auto ISO feature is the one for Shutter Priority minimum shutter speed. To access full Auto ISO, you need to scroll down the manual ISO list, where you’ll find the Auto ISO setting.

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  2. Gh Navabzadeh

    Thanks a lot . Actually it’s a while I’m using this mode on my 80d and it’s the only way in several situations. There is only a point that your camera should have exposure compensation in manual mode for full control over exposure. Unfortunately previous Canon models did not have this feature and fortunatly Canon has started putting this feature for a while.

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  3. Mike Christelow

    My Pentax K3ii has a Pentax-specific mode of Tav, where both aperture and shutter are under my control but ISO is auto. I love it! I was sceptical at first, especially about noise at higher ISO values around 3200 but I needn’t have worried. My biggest problem now is making myself use other modes now and then, to keep the brain sharp!

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  4. Marco Casco

    This is the way I’ve been using my Fuji X-100 at night, 1/60, F4.0 and Auto ISO up to 3200, it works.

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  5. Marco Casco

    Love this !!! Have always wondered if this would work, it does, just great !!! Thanks.

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  6. Rob Cunningham

    I was always an auto ISO guy so I love this article. However there’s another option that I like even bettter. Set your aperture and shutter manually, then assuming your camera supports this easily, use the ISO dial to manually dial in the exposure you want. This allows you to set your exposure for an environment and then roll with it without worrying about locking exposure, or accidentally over/underexposing as your meter adjusts to what’s in front of the spot meter point. I know in theory that’s what the exposure compensation dial is for, but when shooting highly backlit subjects I find that I’m spending too much effort trying to get the camera to meter on the right thing and then dial in compensation and lock exposure. The ISO dial lets you adjust and it won’t jump around as the metering changes. This is why I’m considering changing to the X-T2 for its dedicated ISO dial, even though I prefer the form factor of the X-Pro2. Maybe the X-Pro3 will add a dedicated ISO dial? One can hope.

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  7. Mike Kiefer

    Very interesting. Will auto ISO work similarly when in video mode using my D750?

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  8. jeremy rundle

    Great professional video

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  9. Ron Rosenberg

    This is a fantastic idea – I’m going to try this when I’m shooting on my next backwoods hike. Thanks!! :)

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  10. Domènec Vallès

    I do indoor sports, too. Auto ISO is the way to go, period.

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  11. Graham Curran

    I’ve been shooting manual and accidentally using this technique without really realising it. It was certainly a lightbulb moment. It’s a shame that this article is ruined by glaring typo in the exposure triangle graphic.

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  12. Jim T

    I think this method is now the best ‘Auto’ method for somewhat experienced photographers. Once you have a feel for the different aperatures and and shutter speeds all you have to do is monitor your ISO as you are setting up your shot. If you don’t like the ISO selected you just have to spin your front or back dial until you get an ISO value that you can live with.
    I do sometimes wonder if my Nikon dials can handle all of that spinning without failing after some amount of time. Maybe someone could weigh in on that. Another feature I would like is a way to store and toggle between two exposures instantly. When shooting anything that can move, it is either relatively still, or in motion. Like birds…You need 1/2000 or so to catch their motion, but only 1/320 or so when they are still. It would be nice not to have to spin the the exposure dial so far to get from one to the other. Most of my Nikons had the U1 and U2 settings which could be set up for that, but my new D810 doesn’t have that feature. They took a different route on it.

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  13. Robert Sheppard

    Auto ISO in manual mode with exposure compensation is especially great for street photography – its a shame not all camera manufacturers understand the need for it.

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  14. Thomas Horton

    I really need to learn how to set auto-ISO on my camera. Perhaps it is a hold over from the film days but I often forget that I can adjust the ISO “mid roll”!! I have blow so many shots because while I am manually adjusting the aperture and shutter, I, like a bone head, forget about the third edge of the triangle. (smacking head)

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    • Alastair Archibald

      Adjustable ISO was amazing to me when I started on DSLRs, including ISO settings you just couldn’t get in roll film. But I like this Auto ISO setting even better.

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  15. Nick Chan Abdullah

    good for street photography i reckon? plenty of randomness. people can be idle, can be slow, can be running

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  16. Basit Zargar

    nice one for beginners

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  17. Thorsten Ott

    Auto ISO on manual is great for BOTH available light AND speedlights. I forget where I learned this trick for weddings. Been doing this on the D600, D610 and now the D750.

    I do limit the ISO to 5000 on the D750. Some folks limit at 6400 but I feel that 5000 is a bit cleaner. Dfine plugin does a superb job on noise and I have even shot as high as 12,800 with excellent results when the image is properly exposed.

    These new full-frame sensors are truly amazing and have changed the way I shoot.

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  18. Eduardo Buccianti

    For Nikon D80 I had to go into the Custom Settings Menu (the pencil icon) to turn on AUTO ISO. According to Ken Rockwell ( this is a firmware defect. Look here ( for detailed instructions for the D80.

    Here is a nice “add-on” to Auto-ISO + Manual Mode: I have my AE-L/AF-L button (also under the Custom Settings Menu) set to AE lock hold which means that pressing the button will lock:
    1) the aperture when in Shutter Priority mode
    2) the shutter when in Aperture Priority mode
    3) the ISO when in Manual mode (they should have called the button AD-L/AF-L/AI-L)

    Let’s look at the third possibility since this is the one that concerns us right now.

    If I had Auto-ISO + Manual mode enabled and I pointed my camera at a very dark subject my ISO would automatically adjust to 1600 (the highest in this camera). Now if I pressed my AE-L/AF-L button the ISO would remain locked at 1600 even if I pointed at a very bright subject, like the sun.

    I’ll probably never use the function in exactly that way, but let’s look at a second/inverse example, which could be very useful:

    If I had Auto-ISO + Manual mode enabled and I pointed my camera at a very bright subject my ISO would automatically adjust to 100 (the lowest in this camera). Now if I pressed my AE-L/AF-L button the ISO would remain locked at 100 even if I pointed at a very dark subject.

    This would be useful when working with a tripod. Since camera shake wouldn’t be an issue I would like my ISO to be as low as possible. Instead of having to go into the camera’s Menu and turning off Auto-ISO I could instead point my camera at a very bright subject and lock the ISO there before I start the session. If the camera is already perfectly in place on the tripod I could shine my phone’s light (maybe even use a flashlight app) towards the camera to get the ISO I want to lock.

    The only problem with this is that it would be virtually impossible to set a specific ISO somewhere between 100 and 1600. If the camera could show its auto-updating ISO number it would make this a lot easier. It would actually be a useful feature to have in general. By the way I’ve tried setting my ISO while I have Auto-ISO turned on and it did nothing. I even tried locking my selected ISO in different ways but it seems that selecting Auto-ISO makes the dedicated ISO button completely obsolete.

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  19. Steve VanSickle

    I use this all the time when I’m shooting event photography. When I’ve got a speedlight, I’ll pick my aperture, and drag the shutter to preserve the ambient light, and let TTL + ISO figure the rest out.

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  20. Pentafoto Tm

    Might as well put it in Auto, since you’re at it. I always set my ISO according to the scene, my f-stop according to my DOF need or the light, and the exposure time as low or high as I creatively need, generally high enough to avoid shake or shaky subjects.

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  21. Pompo Bresciani

    I have used auto iso at concerts where light changes very quickly and with a Canon 1Dx it worked out pretty well, in other situations I still stick to manual.

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  22. Laura Tenney

    I agree. To me it is more important to have control over the aperture and shutter for creative intent and let the ISO change for exposure.

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  23. Daniel Lee

    Prior to getting my 6D, I would use AV to meter the shot then dial it into manual and make adjustments when shooting static subjects. AV was my main mode but since getting the 6D and not having to worry as much about high ISO’s, I’ve actually used manual with auto ISO for most of the past year. Even if you don’t want to constantly shoot with auto ISO on, you can just set your aperture and exposure then use the camera to meter your ISO and make adjustments from there (I like to ETTR at high ISO’s). For fast and wide lenses like the 35mm f2 IS from Canon, using AV with your ISO set can be fine but with longer lenses that require a much faster shutter speed, M with auto ISO can be much more convenient!

    Great article and well worth the read :)

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  24. Rafael Steffen

    Really great article to start thinking in a different way in terms of exposure! I will definitely give this a try out!

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    I think auto iso can be a useful tool if you remember to set a limit. If you never set a limit, your experience using auto iso can be very ungrateful.

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  26. Romualdas Stonkus

    Works with Canon 5D Mk3 and it is easy to setup (just change to Manual mode and change the ISO to auto, which is one of the ISO values on the list). Works well and I use that from time to time.
    Besides that, I’ve setup controls in a way, so that I can change ISO without fumbling with many buttons. In 5D Mk3, one can setup via custom settings so that ISO can be changed by pressing and holding “Set” button (the one in the middle of quick control dial on the back of the camera) and turning the main dial (the one in front).
    In that case, all 3 settings are available at your fingertips.

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  27. John Cavan

    When I’m wandering about the woods or streets with changing shadows and light, I usually use the auto-ISO in manual (which was TAv mode when for me when I shot Pentax) with shutter and aperture settings that I think will give me the best results for sudden opportunities. It’s generally worked really well for this, though not without limitations when subjects are backlit.

    When I’m in a controlled environment or shooting landscapes with little change in light, then I simply shoot full manual mode. However, the “m” setting is pretty much assured either way. :)

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  28. Jack Parkinsom

    Shall have to give this a try. Currently using aperture priority with auto ISO unless I’m in one place for long enough to set the ISO myself without having to worry :)

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  29. Karsten Qvist

    This is a great tip, and very well explained here. Only discovered this method a couple of month ago, where I bought a new compact where my usual auto A + auto iso approach resulted in ridiculously long exposure times, so I had to find another way – which turned out to be better…

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  30. Arnold Ziffel

    A la Pentax TAv mode.

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  31. Andrew Merefield

    I learned long ago to never write anything before coffee, every now and then I forget and instantly learn all over again why I shouldn’t.

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  32. Andrew Merefield

    A small pedantic comment, but depth of field is the amount of the image that is sharp, not the amount blurred, so at f16 you have lots of depth of field not none and blurring the image in post would be trying to reduce the depth of field not adding it.

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    • Anthony Thurston

      Right you are sir, not sure what I was thinking this morning (not enough coffee apparently). Still, the point of what I was saying stays the same.

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  33. Kim Farrelly

    I find using M with auto-ISO is great setting, particularly good during something like gig photography. The camera is way faster then me with it, although there are times when I have to take over for a bit. It’s a good balance of speed and control.
    The Canon 5D3 is really fast with it, how do you find the X-T1 Anthony?

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    • Anthony Thurston

      The X-T1 is great with this setting Kim. Like you said, I sometimes have to take over, but overall I love it and shoot with it on 50-60% of the time.

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  34. Jill Schindel

    Food for thought, thanks for the article and video. Often I’m shooting in aperture priority, and setting my ISO to influence the resulting shutter speed – mostly because that’s how I learned how to use the camera, and so it’s how I can “think” the fastest about my shots. I usually tip it into manual with auto ISO if I’m finding I’m primarily concerned with the shutter speed. I’m too nervous about my camera’s selection of aperture to throw the camera in shutter priority as it will often select an inappropriately wide aperture before it will bump up the ISO, and if I’m going to be controlling both SS and Ap, I might as well be in manual.

    Thanks to this advice, I’m going to restrict myself to manual + Auto ISO for a week and see how I like the results. My T2i’s noise levels aren’t great, but they can be salvaged reasonably with Lightroom, where I agree that “fixing” motion blur or an inappropriate DOF is less realistic.

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  35. Calvin Ho

    What a coincudence. I was shooting my daughters Christmas play last week and was using exactly the technique you’re describing. I figure what’s the point of having an expensive dSLR if you’re not going to trust the sensor to do its job at high ISO.

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  36. Austin Swenson

    I think I would only really worry about auto ISO in dim lighting, like in candle light portraits, but I think I would say that I can see a reason to use both depending on your situation. In sports, I definitely think that using auto ISO is good, because it’s far less important if there is noise, but you wouldn’t also want to use auto ISO if your shutter speed and aperture were crappy either.

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  37. Steven Pellegrino

    I manually set my ISO. I know my cameras can handle a higher ISO, but depending on what I’m shooting I will make adjustments to my shutter speed and aperture before increasing the ISO. If I can’t get what I need out of those two settings, then I bump up the ISO.

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    • Anthony Thurston

      To each their own, Steven. In my opinion, people get waaaay too worried about noise and ISOs. Personally, I would rather keep the creative side of the image in my control (Aperture/Shutter speed) and let the camera set the ISO within the limits that I set.

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    • Ian Norman

      I agree with Anthony here. From a technical standpoint and for the maximum image quality, Manual mode with Auto ISO makes much more sense than any other program mode. Maximizing light gathering power based on your setup translates to cleanest photo for the light in any given scene. I always use this mode, picking the longest reasonable shutter speed and largest aperture for my desired depth of field. For example: for portrait session with a 55mm/1.8, I typically stop down to about f/2.2-2.5 for sharpness but short DOF, and use 1/125th of a second for minimal motion blur handheld. Auto ISO just set’s the gain as needed, easy peasy.

      This technique is especially beneficial with today’s ISO-invariant sensors (Canon being the exception with their ISO-variant sensors), ISO now has essentially no effect on noise. It’s a commonly perpetuated misconception that higher ISOs increase the ratio of noise in an image but in any given light condition, if your shutter speed and aperture remain the same, the ISO has nearly no tangible effect on noise, it’s essentially just like tweaking the exposure slider in Lightroom.

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    • Holger Foysi

      I do manual+Auto-ISO at 95% of my cases. Only when strong backlighting happens do I use full manual control. Found it much better with animals, when I suddenly have to change shutter speed as soon as some action happens.

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