Flash and high ISO sensitivity

There is an excellent guideline for managing the ISO sensitivity value. It sounds something like this' Try always shoot at minimum ISO'. But sometimes this rule has exceptions.

Flash and ISO Values

Flash and ISO Values

High ISO sensitivity values ​​are usually needed when you need to take something without grease in poor lighting conditions. If it concerns the shooting of people, then usually shooting below 1/60 of a second is simply impossible, this is due to the fact that the person in the frame usually moves, the camera moves in his hands, and for a long time excerpts the picture is blurry.

Under low light conditions I understand approximately such that with the maximum aperture of your lens and with the maximum acceptable acceptable ISO value excerpt longer than 1/60 of a second. This is my subjective definition. For example, for a weak camera, normal evening home conditions with the lights on are already bad.

Sometimes it’s just not possible to get the right shot with a short shutter speed and low ISO. In this case, you can:

  1. Open aperture as much as possible. But almost always opening the diaphragm does not save much. For example, when I shoot with fast zoom lenses, I can have the number F not less than F2.8, this is due to zoom restriction. As for the fixes, they can be used to arrange the numbers F1.2 and F1.4, but with such apertures, the depth of field becomes very small and the focus errors increase very much, and the efficiency when shooting using a fixed lens is also greatly lost.
  2. Increase ISO. With an increase in ISO, after a certain value, the noise level becomes critical, and the photos are unusable.
  3. Take advantage of the flash. But flash often "kills" the atmosphere of the photo, makes unnecessary shadows, highlights and red-eye.

When using a flash, many photographers set the minimum ISO, thereby achieving an absolutely silent picture. On the one hand, this principle has its own logic, because why high ISO values, if there is a flash? But in most cases, photographs in low-light conditions are obtained with an unfinished long-range plan. This is due to the fact that the flash only highlights near subjects well when shooting. Roughly speaking, the flash only highlights what is in the focus area. When calculating flash power, many cameras are guided by the focusing distance to the subject, which is calculated using the lens processor. For everything else, the elements in the flash frame do not care.

I will explain what is not worked out (drowned, killed) distant plan on an example below:

The background (background) is all dark.

Flash photo. The background (background) is all dark, not exposed. And the front, on the contrary, is highlighted. This creates a kind of hard image.

Below is an example of the same shot without a flash:

Photo without flash

Photos without flash at high ISO. The picture is more lively, with a well-developed background and foreground.

It’s good when you can do with the usual raising of ISO and turn off the flash. But in many cases you still have to use a flash. To keep the background you can simply increase the ISO values ​​when the flash is on. This will allow you to get a well-exposed flash object in the focus area and a more or less balanced, not recessed background.

Flash photo.

Flash photo. The person in focus is well illuminated by the flash, and due to the fact that ISO 640 was used, the distant plan was also recognizable.

This effect occurs due to the fact that when using the flash in poor lighting conditions, they are usually used excerpts from 1/60 second to 1/200 second. With such exposures, blur is not permitted when shooting with handheld. Example: if you take pictures at ISO 100 and 1 / 60c with a flash, then the light from the background will not be able to display (appear) well in the photo. At the same time, if you raise the ISO to 800 units, with the same 1/60 second and the included flash of light from the background, it will get 8 times more, which will allow it to manifest more strongly.

Also, flash shooting at high ISO allows you to:

  1. Save energy on flash batteries as flash pulses become less powerful
  2. The flash overheats less, works longer
  3. Flash range increases when ISO is raised
  4. When working on reflections from walls and ceilings, the effect of filling with flash is more pronounced

I shoot with the flash in automatic modes (TTL, Auto without TTL) in aperture priority mode (A, AV) and manual mode (M) at ISO 500 - ISO 1000 to get a pleasant picture and avoid loud noise.

Sample photo

Sample flash photo at high ISO. If I shot at low ISO, the clown would have turned out on a black background.

When the background itself is black, little will help. If my will, then I would shoot everything without a flash, it is more interesting, it requires more skills and skill when photographing, more fast lenses, better camera performance when working at high ISO. External flash, mounted on a camera, kills all the listed advantages. But the lighting systems on off-camera flashes are to my liking. But almost always when ordering a shoot in low light conditions, the first question people ask is: 'Do you have a flash?' Sometimes it is difficult to explain to a person that pictures without using a flash can convey the atmosphere much better, be more emotional, soft, artistic. And in some cases it is simply stupid to use a flash.

Well-designed background

A well-designed background, but the flash kills the atmosphere, gives glare from the glass of icons.

Personal experience

When shooting with an external flash for myself, I do a little trick. When external flash on the camera is off, I try to turn the flash head to the right, or to the side of my face, this always reminds me that the flash is off, and people do not look so intently at the fact that the flash does not blink when the shutter clicks. In general, working with a flash requires a certain subtlety, and when working with a flash there are many limitations, inconveniences, etc. I never even thought that many shooting with a flash set the minimum ISO value, so I decided to write some thoughts on this. I recommend doing your own experiments when shooting in low light conditions with flash and different ISO settings.


Flash shooting at high ISOs is very common. For each camera, you need to calculate your ISO threshold, which allows you to get a little noisy picture with a flash.

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Material prepared Arkady Shapoval. Training/Consultations | Youtube | Facebook | Instagram | Twitter | Telegram

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Comments: 87, on the topic: Flash and high ISO sensitivity values

  • Levani

    class! ) I did not know this, I will adopt a bright idea :-)

  • Alexander

    Thank you, a useful article, especially for owners of new models, which at high iso show good results.

  • Sergei

    This is good advice! Just in April I buy a flash, I will try to raise the iso while I learn to take pictures with it ...
    although everyone chooses what he likes ...

  • Vadim Gadzira

    Thanks for the helpful article Arkady! I would also like to add on my own ...
    I also shoot with flash, at high ISO values, to draw the background, and I advise you to use this technique for those who have to photograph a lot (for example, a wedding), since this mode saves the battery power of the flash to a great extent. It doesn’t need a lot of impulse for proper exposure than when using low ISOs. For example, my SB-900 works at ISO 100 150 frames. And with ISO 800, 600-700 frames ... Draw conclusions gentlemen! I wish you successful shots and inspiration!

  • Oleg

    good article. but all this had to be done with the mind. on my nikon d 600 (full frame) costs 28-300. pyha 700 nikon. I do not put iso less than 400 almost never, or even 800, it turns out then not bad. Maybe it could be put lower than ISO …… .but the lens is too dark.

  • i-hero-in.narod.ru

    Flash is a useful thing, but the atmosphere really spoils a lot. A lot depends on the RAW converter: when I didn't have an external flash, I even used ISO 70 on my D1600s. The shots were very noisy - it was frustrating. And recently I developed one of those photos in Capture One. The result was amazing - apparently a good noise reduction there. Now I'm shooting on D90 + SB600 + diffuser (thick paper sheet and cloth, flash up). I set ISO from 400 to 800. I shoot with fixes with aperture 2.8. On the flash, I set a minus correction of about -1.3. In this case, the photos appear to be underexposed (low-contrast), but without overexposure and the background in a small room is well worked out. When you have to shoot with a dark zoom at a great distance, you have to hit the forehead with a flash with a minus correction. But the background has to be drawn out in the converter by lightening the dark areas. In theory, it is better to underexpose the photo than to blur it with a long exposure. And converters now allow you to more or less pull everything from a photo without much loss.

    My question is - what kind of lighting and settings do you use in dark restaurant-like rooms?

    • Arkady Shapoval

      In each individual situation, you have to use your own selection of settings and lighting. All sorts of restaurants / corporate parties without an assistant I shoot with the usual flash from the ceiling, ISO and exposure to taste. I love M 1 / 80s (depending on the lens), from 500 to 1000, a flash in auto-TTL and a correction for flash power + -, for which they wrote here in the comments.

  • Gene jb

    By the way, I remembered pictures from the church, there it is, there is darkness behind.

  • Gene jb

    Noise can be killed by the megapixels by the way. The more megapixels, the finer the noise (though the shutter speed is longer). With noise reduction and resize, at least 2 times the noise will go away. It will be necessary for Arkady to write an article about this.

  • Dmitriy

    Eh, I would have gotten this article a little earlier, otherwise I was filming a holiday of friends here the other day at minimal iso and was upset.
    Thank you.

    • Sergei

      a wonderful article, but those who use a camera to take a lip reflection letter PY on a cool photo with a mirrored device may not know this, but those who have at least a little light on photography probably came to this as I did) ATP good article

      • anonym

        so if such a fine fellow that CAM came to everything, so he might not have come in and not read articles.

  • Alik

    Thanks so much for the article!

  • Roman D

    Arkady, you are not entirely right. The flash very often works in TTL mode (not only for me, for the vast majority). The SB-910, for example, is a monster in terms of lighting algorithms. If you set a center-weighted algorithm for determining the power of the puff on it, it will not care about the background. Raise ISO, it will puff weaker (M mode on the camera - only it is for shutter speeds shorter than 1/60, TTL mode on a flash is the most common cases, besides, a flash into the ceiling or an umbrella). In order not to kill the background, it is necessary to act according to a different algorithm.
    In mode A with the flash turned off, hover over the background, the minimum ISO, the necessary aperture, the CV was measured with a minimum area of ​​the circle. We look excerpt. If not satisfied, increase until it suits. If the exposure compensation is 0, you can extend the resulting shutter speed by 1 / 3..2 / 3 so as not to force the ISO too much. We remember the aperture and shutter speed, switch to M mode on the camera, set those values, take a picture.
    This algorithm works well only when the illumination of the subject is lower than that of the background. With equal illumination, you can shoot without a flash. In low light conditions, only the background is highlighted, but that's another story.

    • Arkady Shapoval

      A lot of trouble with switching am, memorization, etc., as described above, such an algorithm is not suitable for any fast-moving wedding.

  • Roman D

    In addition to the previous one.
    Read "If you are not satisfied, we increase ISO until then ..."
    For example, with a bouquet from the article. The illumination of the bouquet and background are close. According to the above algorithm, the flash will fire at minimum power. Her work in the final picture will be practically invisible.

    • Arkady Shapoval

      In fact, even in such a situation, the effect of the flash will be noticeable.

  • Roman D

    And in addition to the previous one. Arkady, your statements are true for mode M on the camera (like my presented algorithm) and not at all for mode A. It's just that in your case the result is known only after clicking, and in my case - before.
    You still can’t switch to mode A, but right in mode M it is aimed at the background and looks at the exposure scale, trying to set the pointer to zero ONLY due to ISO with the required fixed aperture and shutter speed.

    • Arkady Shapoval

      Nothing like that, in mode A, the camera, when correctly set, takes a shutter speed from 1/60 to 1 / 200s in low-light conditions, and the exposure scale for which you write can be wonderfully set on the exposure scale in the optical viewfinder. For example, on my Nikon cameras, when the flash is on, the exposure scale is visible, which shows a really exposed frame without flash pulses. At the same time, it is possible to fine-tune the scatter of values ​​without mocking from A to M and vice versa. Constant torsion here and there is often unjustified in terms of costs, it is easier to use the average allowable value, for example, iso 640, which allows the background not to kill or bother too much.

  • Igor

    I know how, I know, I practice! =) Thank you Arkady!

    • Alex

      ... forgot to add "share" :)

  • anonym

    Thanks for the article I did not know.

  • Ivan

    The article is good, I made a lot of dark plans so far. Of course, without a flash it is better, but on a crop in a room in the evening without a flash it is difficult, large iso noise. I shoot with a flash in manual mode, ISO in the range of 400-800.

  • Beery

    Thank you, Arkady, you covered a very relevant topic!
    But have you ever had to practice with flash sync on the rear shutter when the flash fires just before it closes? In this case, the background should be worked out as well as possible, plus a flash for the front. Share your experience with this mode.

    And thanks again for sharing your thoughts about the photo :)

    • Arkady Shapoval

      Sometimes I use it, I will write time.

  • Andrei

    Tell me, please, and if, with a robot with a built-in flash, for a better study of the background, instead of raising the ISO, say, open the aperture by two stops by two stops, the pictures will be the same or ...? Ie raising the ISO will do the same as opening the aperture?

    • Novel

      No. Closing the aperture increases the DOF (the degree of blur in the background varies greatly) and often just sharpens it. Many (especially old) lenses on open soft and chromate. Therefore, opening the aperture is an extreme measure, when it is no longer possible to raise either shutter speed or ISO.

    • Arkady Shapoval

      Opening the aperture with a flash at standard shutter speeds will also help in drawing the background. Closing the diaphragm during a flash, on the contrary, will completely kill him.

    • Vitaliy U

      The diaphragm can be opened / closed, compensating for these movements with shutter speed.

  • Andrei

    About DOF, I know aberrations. I am interested in the background in terms of illumination. That is, will it become lighter when you open the diaphragm by as much as from raising ISO?

    • Dmitriy

      How it will become! You can experiment on your own - choose the standard values ​​and take a photo of the box illuminated by a light bulb - then change the aperture value (at standard shutter speeds and ISO), then do the same with the shutter speed (at standard apertures and ISO) and do the same with ISO. You will see that the open aperture, then the shutter speed, and then, with a lag, the ISO affects the drawing of the light backdrop the most.

  • Vasil

    Vikoristovuvu qiu trick himself knowingly. I don’t know more about the situation in the P mode + the message (it’s normally more normal then without it) + automatic ІСО. Vdoma provіv kіlka eksperimentіv і having swayed, what for a friend 10х15 go to take a photograph at іso 3200. I want more beautiful nevikoristovuvati more than 1600-2000 more noise all the same є. But for my camera, I don’t know for those who are new (:

  • Irina P.

    Ark, thanks for the necessary and instructive article. I emphasized a lot of useful information for myself and have already managed to successfully experiment :)

    Thank you.

  • Semen

    Something the teacher left his students. And we wander without a shepherd, answer me ... We thirst for knowledge!

    • Arkady Shapoval

      If this is you about me, then I am not a teacher and not a shepherd. Do not forget and do not write nonsense.

  • Semen

    It was of course a joke. You just did not answer a couple of days. In general, I wonder how you find all the time. A wonderful site, articles, reviews. Thank you, very interesting and informative.

  • Jury

    Indeed, the site is excellent.

  • Igor

    Dear, Arkady.
    I noticed a typo in the text:
    Example: if you take pictures at ISO 100 and 1 / 60c with a flash, then the light from the background will not be able to display (appear) well in the photo. At the same time, if you raise the ISO to 800 units, with the same 1/60 second and the included flash of light from the background, it will get 8 times more, which will allow it to manifest more strongly.

    The difference between ISO 100 and ISO 800 is only 3 steps and, accordingly, the light will not hit 8, but 3 times more than with ISO 100.

    • Arkady Shapoval

      You are wrong. 3 steps is 8 times, 2 ^ 3 = 8. See for yourself, at ISO 100 and at ISO 800, the difference in shutter speed at the same aperture value is 8 times (and 8 times less light will enter). 3 steps and 3 times are not the same thing.

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