Sometimes You Have to Photograph at High ISO Outside During the Day

Sometimes You Have to Photograph at High ISO Outside During the Day

High ISO is usually meant to be used when there's not enough light. However, there are cases when you have to take it up from its minimum value even when the sun is bright.

There's nothing tricky about that statement. You will see it's all about physical and optical demands that you need to put a bit of grain in your images in order to get a decently exposed and sharp image.

Sunny Sixteen Rule

Talking about the sun, let's remember that rule which helps you guess the camera settings on a bright day. The rule states that if the sun is strong, you can use aperture of f/16, shutter speed 1/X seconds, where X is your ISO. Let's say you're at ISO 100, which means that the triplet f/16, 1/100, ISO 100 will do the job fairly well. At that aperture, you will have a very deep focus, which means those bokeh-lovers among you won't like it. If we set the aperture at f/5.6, we are three stops brighter, and we need to change the other two values a total of three stops in order to compensate for the brighter image and make it normally exposed again. Let's say we are decreasing the ISO to 50 (which is one stop) and we increase the shutter speed two stops. The final settings will become f/5.6, 1/400 s, ISO 50. Bokeh is not always a cool thing, and f/16 is an aperture you should also consider.

Now imagine you have to photograph a subject in the shade where it's usually at least three or four stops darker. The sunny sixteen rule will be almost the same, but instead of f/16, you have to think of f/5.6 or f/4.0, 1/X sec, ISO X.

When Lenses Limit You

You don't have the freedom to use any shutter speed with any lens, especially when handholding the camera. In general, you have to set your shutter speed at least a 1/L, where L is the current focal length of the lens. For a 200mm, lens you need to have a shutter speed of at least 1/200. Lower shutter speeds can work for you if the camera or the lens have good stabilization and you have steady hands.

Sample Use Case

I photographed that beautiful model in the leading image using a strobe. I set my lights under the shade. I used a 135mm focal length. According to the rule of thumb above I needed about f/4.0, 1/135, ISO 135. My light meter told me to photograph it at f/3.5, 1/80 s, ISO 100, which was fairly close. Having that focal length required my shutter speed to be at least 1/160. At f/3.5, 1/160, ISO 100, the image was one stop darker. As the child was moving around, I set my aperture to f/5.0 in order to have a bit of a deeper focus. This way with a moving model, I might have more images in focus. This made the image an extra stop darker. I compensated with two stops of ISO, setting it to 400. The final settings were f/5.0, 1/160 sec, ISO 400. I used flash and the shutter speed was just fine this way. Here's the order of changes one more time:

  • f/3.5, 1/80 sec, ISO 100 - Light meter said so
  • f/5.0, 1/80 sec, ISO 100 - For a deeper focus depth, but made image one stop darker
  • f/5.0, 1/160 sec, ISO 100 - For a more stable image at a 135 mm focal length, but makes the image one extra stop darker
  • f/5.0, 1/160 sec, ISO 400 - Compensating with two stops of ISO

Cases like that are especially true when you photograph landscapes without a tripod or portraits where you want deeper focus. For those who don't think portraits look any good without a blurred background, think of photographing groups of people who are not on the same focal plane (like for a movie poster or a corporate photograph), music band members, fashion, and others. If you happen to use flash, you need to be also aware of your shutter sync speed limitation.

Conclusion

The relation between the lens' focal length and the shutter speed is the most common reason for bumping the ISO up during daytime. This should not be deemed an exception, but a normal case. It's much better to have a grainy, but sharp image rather than a clean and blurred one. Moreover, today's cameras are performing great at high ISO values.

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19 Comments

"People ask me what kind of tripod I use when shooting architecture. I tell them, 'ISO'..."

Spy Black's picture

I just use whatever ISO I need. If I'm shooting with a long lens in daytime I'll probably be around 800-1600. Similarly if I need the lens stopped down and the shutter high. When there's adequate lighting high ISO is not that objectional looking.

It does not matter if you have 5 stop IBIS or OS. It doesn't freeze the motion of the subject you photograph. Yeah, like kids who can't stay still that even 1/100sec shutter is still not fast enough sometimes, and your only option is to bump up the ISO.

I'd rather increase iso rather than getting a slightly blurry shot that cannot be fixed. Of course some people will definitely accuse me that i increase iso freely whenever i can without second thoughts because I'm using a full frame.

Black Z Eddie .'s picture

I'm not sure if ISO 400 is really a "high ISO".

Tihomir Lazarov's picture

That was the latest example I found on my computer. The others were in the NAS archives and I was too lazy to dig into them :) I used this image just to show the principle.

user-216690's picture

I've been finding that my tripod isn't tall enough to clear the undergrowth in forests (I can't justify that super tall tripod yet, $1,500 is a lot of money for a toy), and so I've taken to pushing up the ISO and holding the camera above my head (yeah, I can't justify a camera with IBIS or OS either, given that my existing cameras are quite adequate).

Personally I find this method explained in an unnecessarily complicating way. I think it should be described along the lines of "how to use ISO to get sharp images with forgiving DOF and great exposure."

We don't need to get excessively mathematical with photography all the time.

Tihomir Lazarov's picture

You got me. I'm paid by the number of letters in the article and the level of complication. Jokes aside, I think the content is explained clearly enough teaching the readers not only using high ISO at night time, but also at daytime plus a principle to make a rough estimate on the settings that can be used at different situations (only for those that work in manual mode).

Oh of course I applaud the effort for sure mate.:) Guess I was just tired of reading too many articles on the web written in the same vein.
But pls keep doing what you do and thank you for your inputs and tips. I'm sure we will benefit no doubt.:)

gabe s's picture

Compared to what sometimes qualifies as an article on this site, this piece was Pulitzer worthy.

Claudiu Ion's picture

Your calculations and the picture with the girl has nothing in common. F/5 1/160 and ISO 400 means 5 stops brighter than correct exposure for Rule of sunny 16. 5 stops brighter means you should have blown the whole background. Please go outside and expose with these parameters and see what's happen. You would't be able to recover the exposure, even if you use a raw file.

Tihomir Lazarov's picture

That's "shady 4-5 rule," if I have to be exact having an aperture of f/4 or f/5.6. In the article I have stated that this portrait has been photographed under a thick tree shade with a strobe. The lighting ratio was 2:1, so it's not far from a natural light portrait settings.

The image is straight out of the camera. No other conversion than what Capture One's default conversion was and then exported to JPEG.

Claudiu Ion's picture

On the left side, on the background, I can see some foliage in direct sun light, that area should be 5 stops overexposed. Are you sure you didn't use high speed sync and in fact the shutter speed was 1/2500 - 1/4000 sec.?

Tihomir Lazarov's picture

I haven't used high-speed sync (my gear is not capable of that) and my settings were exactly f5, 1/160, ISO 400. The sun was at about 1-o'clock from my point of view, the background was mostly backlit, but there were many clouds too. The sky wasn't perfectly clear.

I just checked the settings in Capture One. It seems I lied about something: I had bumped up the exposure in post by about 0.5. The image was even a little underexposed, not overexposed.

By the way, I don't remember if I have used any NDs here. I rarely use NDs unless I shoot video. If there were NDs the principle would be the same though. This may be the probable answer to your confusion. Unfortunatey I don't remember as the ND is not in the EXIF :)

Tyler Jacobs's picture

Cool tips. I used to carry two cameras - one with 100 iso on a 50/1.4 & another with 400 iso - usually on a telephoto; for this reason.

Tihomir Lazarov's picture

You probably meant ASA instead of ISO, as carrying two digital cameras can be assumed as a joke :)