A common misconception in landscape photography is that using the lowest ISO setting always results in the highest quality images. I frequently encounter this question and concern in my YouTube comments. Therefore, I thought it would be the perfect opportunity to share a video and article discussing the importance of ISO.
While a lower ISO can effectively minimize noise, adhering strictly to ISO 100 can limit your adaptability in dynamic or challenging shooting environments. In reality, embracing the flexibility to raise your ISO when necessary can enhance your creativity and help you capture sharper, better-exposed images. Additionally, it's essential to recognize that the flexibility of your ISO settings depends on your camera sensor's capabilities. I recommend doing ISO tests on your camera to see how it handles higher ISOs or reviewing tests online to better understand its performance. Be sure to check out my YouTube video for a more in-depth look at this subject, complete with image examples.
ISO 100: A Default, Not a Rule
While I aim to use ISO 100 whenever possible for its noise-free quality, real-world situations often make this challenging. The ideal scenario rarely presents itself, especially when capturing fast-moving or unpredictable conditions. By being open to adjusting your ISO, you can gain more flexibility in your shooting.
There was a calm waterfall exposure, with no wind, super stable ground, and enough light to shoot at my ideal default settings. I opted for a 0.6-second exposure at f/11 and ISO 100 for this shot.
ISO Flexibility in Fast-Moving Environments & Windy Conditions
When shooting from helicopters or boats, the constant motion and vibration make capturing sharp images at ISO 100 rare. In these situations, I typically raise the ISO to 400, 500, or 800 to enable faster shutter speeds, which are essential for avoiding motion blur.
For instance, while shooting from a helicopter, the rapid shifts in perspective and vibration would lead to blurriness if I remained at ISO 100. By increasing the ISO, I can boost my shutter speed, ensuring the scene stays sharp and detailed. Below is an image shot in Hawaii from a very turbulent helicopter ride. It was incredibly chaotic, and pushing my ISO to 400 allowed me to capture this image nicely. The scene was also not very brightly lit, as you can see from the diffused lighting here. So, I needed to open up my f-stop to f/4 (my lowest) to expose the scene properly. It's a moment that I won't have the opportunity to witness again, and being able to capture it clearly and in focus was the most important thing for me.
I also photograph from boats, canoes, and kayaks. Below is an image captured during a stormy boat ride in New Zealand. Freezing the water and getting a stable shot with my telephoto lens meant bumping my ISO to 1,000 to achieve a nicely crisp shot. Even at that high ISO, I was able to get a decent, clean file to work with, and I reduced the noise manually in Lightroom, as Denoise didn't exist at the time.
Now, to switch things up completely, here’s a sand dune image captured at 1.3 sec, f/9, and ISO 100. This was the ideal situation for comfortable landscape photography. It was a calm, windless morning, and I sipped my morning coffee as I took this telephoto image. There was no need to bump the ISO for this one. However, things can change drastically, as I captured the following photo a day later.
Here’s a dune shot, this time at 1/800 sec, f/11, and ISO 400. Even though it was pretty bright out, the wind was very dramatic. Strong gusts stirred up sand, making it impossible to do a long exposure without introducing significant motion blur.
To compensate for the conditions, I needed to bump my ISO up to give myself some breathing room on the shutter speed, allowing me to freeze the action of the wind as it danced across the sand. I also set my f-stop to f/11 to ensure that more of the front dunes remained in focus, providing depth to the image. This combination of settings enabled me to capture the texture and details of the dunes while effectively rendering the dynamic movement of the sand.
In situations like this, adapting quickly and making informed decisions about exposure settings is crucial. This shot illustrates the importance of flexibility in your approach to ISO and shutter speed, especially when faced with unpredictable elements in landscape photography.
This is also crucial when capturing wildflowers in windy conditions. If I need to close my aperture for greater depth of field, I increase the ISO to freeze the flowers' motion, ensuring a sharp image. This was shot at 1/60 sec, f/16, and ISO 500 to get everything sharp while also retaining a clean frame.
Capturing Birds and Moving Objects
Higher ISOs are especially beneficial for capturing moving subjects within a landscape scene. Imagine photographing a serene vista when, suddenly, a bird flies into your frame. If my ISO is set too low, I may miss the chance to freeze the bird's motion without sacrificing shutter speed, resulting in a blurred subject. By raising the ISO to 400, 500, or 800, I can keep the bird sharp, adding interest to the overall composition.
High ISO for Astrophotography
While shooting astrophotography, I often push the ISO to 3,200 or 6,400 to adequately expose the stars and capture the intricate details of the Milky Way. Although this can introduce noise, techniques like exposure stacking and noise reduction tools in post-processing ensure that the final image is clean and sharp.
The images below were shot on my Canon 6D and Canon 5D Mark III in 2013 and 2014. The first image uses a panorama technique to increase the image size, resulting in a cleaner file even at ISO 6,400. The second photo was taken with a star tracker, using multiple images for the sky (stacking them) and multiple images for the foreground (stacking those as well).
So, even with much older camera systems, you can achieve some pretty clean results at high ISOs if you are willing to incorporate a few extra techniques into the shooting and post-processing of your astro landscapes.
Why Flexibility Matters More Than ISO Perfection
Adjusting your ISO allows you to focus on what truly matters: composition, creativity, and capturing the moment. Whether photographing landscapes from a fast-moving helicopter or framing a fleeting moment in nature, raising your ISO provides the flexibility to react to your environment without compromising image quality.
While noise may slightly increase at higher ISOs, modern cameras and software make it easy to minimize this during post-processing. If you would like to learn more about this, check out my tutorials and online workshops here.
If you are someone who has worried about bumping up that ISO in fear of a grainy shot, I encourage you to play around and experiment with higher ISO settings. You might open up a whole new world of photographic possibilities. As always, thanks for reading and watching!
Firstly great images!
It’s the situation that often determines ISO, especially if something in the scene is constantly changing and you need to accommodate that. If the shot demands a certain aperture and speed then the only variable left to be decided on is ISO I normally let the camera do that as I know what I require for the other two. Auto ISO in some situations where you are having to change Aperture or the speed on the fly is a massive help in making sure the exposure is correct. Photographing butterflies and dragonflies are two such situations where you constantly need to change settings depending upon the available light, background and how and if the creature is moving. Don’t let yourself be stuck always using min ISO especially as NR software is so good.
Really great examples on using ISO to control different problems for I even learned some things with the addition of f/# being above the norm of f/8. Using ISO 640 vs 100 may get you a cleaner less noise image because it is like the next step in amplification from 100, Many newer cameras are ISO Invariant meaning you can get a dark image but just increasing exposure in post will get a brighter image at a lower ISO and getting less noise in shadows but brighter shadows.
As far as stacking to help rid noise you are better off to use camera NR, that period where the camera takes capture of darkness and get rid of noise. What many do not understand about NR that is done when a camera shutter speed is longer then 1 sec and you are doing a panorama is today we are using faster lens that like f/1.8 or even f/1.4 that require faster shutter speeds, where we would use a an f/4 lens and get a great image at 25 or 30 seconds but a f/1.8 lens will require a 10 second. Next your camera MP of 12MP or 61 MP the 12MP camera will allow a longer exposure but the 61MP will require a faster shutter speed. So a f/1.4 lens on a 61MP camera you will have to do a 5 second capture. Using the 61MP plus a f/1.8 each capture of 5s and having camera NR on you can go to the next click on your stepper (at the base of your panorama rig) letting you do a 200 degree pano in less than 90 seconds. You see the f/1.8 lenses will not let you do longer captures for you will get elongated stars due to light will pass through the outer edges of the glass. To check you can look at PhotoPills Spot Stars section and select your camera and then your lens f/# you will use it will give the old 500 rule and then the Accurate and Default Shutter Speed and that is also whatever f/# you want to use of wide open to narrow.
If doing Milky Way Panoramas with either 12MP or 61MP and setting ISO/SS/f/# to get a meter mode of zero on each you will get a bright night vision like image just one will be faster then the other. All I am pointing out is stacking in post is a waste of time
1. An old 2015 A7SM1.
2. Using a stepper Pano rig I was able to capture this fast with NR on as fog was rolling in.
Another point about Denoise is each image of a pano can be sent through Lrc Denoise getting say 9 images denoised and sharping again then processed for blending and editing.
Showing two images from two different MP cameras is not needed for both will look alike.
I think most people who learned to shoot in the digital age have learned ISO inaccurately. This is a result of translating film speed to digital ISO. People teach that higher ISO changes the sensitivity of a camera sensor to light and that higher sensitivity leads to noise. That is not at all accurate. A sensor's sensitivity to light is a fixed value base on a lot of things that are not important to this conversation. ISO is essentially an amplification setting that is applied to the signal generated by light captured on the sensor. That's a bit of an over simplification but again outside the scope of this conversation. But what is important here is that noise is present at every ISO. Look close enough to the shadows in images shot at ISO 100 and you might find noise.
It's important to keep in mind that noise is one half of the signal to noise ratio. Signal in photography is light. If you have an image with low signal (low light), your ratio to noise will be low and noise will be more visible. At any ISO, it is important to expose properly. The more light you can get on the sensor, the less visible noise will be. This is true at any ISO. Try it for yourself. Underexpose an image shot indoors at ISO 100. Look in the shadows. Take the same image properly exposed at ISO 400 and look in the shadows again. I bet you'll see more noise in the shadows at ISO 100.
ISO should be used exactly as described in the article here. As a tool to get you faster shutter speeds. Photographers should worry about unintended blur more than they worry about noise. Crank the ISO when you need speed, expose properly and don't sweat noise.
I think I understand your point that a camera sensor's sensitivity remains constant. And that increasing ISO only brightens the picture through internal chip processing... or something to that effect. However, as a matter of terminology, the menu settings in my Nikon D800E do in fact correlate ISO with sensitivity.
As you indicated would happen, Chris, the higher ISO 800 at a proper exposure is a much cleaner image than an underexposed image at lower ISO.
Two things to point out. 1: the value of walking around and handheld shooting sometimes (mostly after I finished my tripod shot). And 2: know your camera. On my Sony iso 640 is better than 400.
Absolutely fantastic images
I'm like a lot of photographers... shoot as low of an ISO as possible until conditions dictate otherwise. I was at the local botanical garden and there were just too many young parents with children and narrow paths to set up a tripod. So I left it in the car, set the aperture to F/18, shutter speed to 1/500, and bumped up the ISO to 12,800. I was expecting a lot of throw-aways. But to Chris Edwards point, there was enough light in the gardens that my noise was not so bad. Color noise is easily eliminated in post-processing, and I found the noise resembling fine grain to be acceptable... perhaps even desirable?
--- "I found the noise resembling fine grain to be acceptable... perhaps even desirable?"
For the last couple of years, I'd add noise/grain in post to literally all my images. Just enough so they aren't so clinically clean.
KNOW YOUR CAMERA. This can not be overstated! Not all cameras apply ISO settings the same way.
Traditionally analog amplification of the signal coming off the sensor before digitization at the analog-to-digital convertor (ADC) was the way it was applied. This included full stops and partial stops. A full stop amplified the signal by 2X the previous full stop setting. A half stop amplified by 1.414X (the square root of 2) the previous full stop. Plus one-third stops amplified the signal by 1.26X (the third root of 2) the previous stop, plus two-thirds stops amplified the analog signal by 1.587X (the square of the third root of two) the previous full stop.
But then camera manufacturers started deviating from this practice. Canon, for example, between around 2008 and up through at least 2018 only did analog amplification in full stop intervals. The one-half and one-third stops used the nearest full stop amplification before ADC, applied a plus or minus compensation for metering (in addition to any EC dialed in by the user) and then included instructions in the raw information to push or pull the development in the processor by the corresponding amount. For example: if ISO was set at 1250 the analog amplification would use ISO 1600, metering would compensate by exposing 1/3 stop brighter than for ISO 1600, with an instruction in the raw data to pull exposure by 1/3 stop. If ISO 1000 was set analog amplification would use ISO 800, metering would compensate by exposing 1/3 stop darker than for ISO 800, with an instruction to push by 1/3 stop. This had the effect of making ISO 125 noisier than ISO 1250! The "-1/3" stops (ISO160, 320, 640, 1250, etc.) were less noisy at the expense of 1/3 stop of head room for the highlights. In effect it was exposing to the right by 1/3 stop and then pulling development by 1/3 stop. The loss of highlight headroom was hardly a concern when shooting in low light. The "+1/3" stops (ISO125, 250, 500, 1000, etc.) underexposed by 1/3 stop then pushed both signal and noise when converting to a viewable image. These "+1/3" stops had both the disadvantage of 1/3 stop less dynamic range AND amplifying noise by 1/3 stop.
Other manufacturers use other tricks. Some claim their sensors are "ISO invariant" leaving the impression they apply no analog signal amplification before ADC and it's all digital. But that would lead to massive issues with quantization errors and blocky gradients of smoothly increasing tones in the scene being photographed. What they're actually doing is applying noise reduction to the analog signal before analog amplification prior to ADC. That's why such cameras are known as "star eaters" among the astrophotography crowd.