Ask PMS – shutter speed tips
This is based on a photo shot at f1.8, 800ISO and 1/30th. It’s a little blurry – what shutter speed tips can we give to make the picture clearer?
Old shutter speed tips are that roughly speaking you can hand hold the camera for the length of the zoom in fractions of a second. So your 50 mm lens in theory can be held for about one 50th of a second. Any longer than that and you’re likely to get camera shake. This is complicated by the fact that your camera is a “crop sensor” camera – the effect of the small sensor on a Nikon means that all your lenses are slightly more zoomed in than they appear. in fact, all your lenses are 50% more zoomed in and they would be on an expensive full frame camera or a film camera. The result of this is that your 50 mm lens actually gives you 75 mm of zoom.
So one of the old shutter speed tips is that you can hand hold your camera with the 50 mm lens for about 1/75 of a second or so.
This is the old rule that goes back to film cameras, but in our experience it’s about right. Most people can’t hold lenses still for much more than the length of the zoom in fractions of a second. So if you had a 200 mm lens on your camera, acting as a 300 mm because of the crop, you would be able to hand hold it for about 1/300 of a second. In practice, if you find that your length of shutter is becoming unworkable, you need to do something about this – either play with your ISO (more later), decrease your exposure compensation (making the picture darker and the shutter speed faster), or using a wider aperture lens. But assuming you’re not going to scrap your lens, what shutter speed tips can we give to help?
The ISO is the sensitivity of the camera, and does double as you increase from 400 to 800 to 1600. So taking the same picture with the same aperture in Aperture priority if you were to increase the ISO from 400 to 800 you would decrease the shutter duration by half. if you then increased to 1600 you would decrease the shutter duration by half again. Most cameras these days can manage 1600 without too much noise, it very much depends on the subject, the genre etc how much noise you can bear. One of our shutter speed tips would be that a dark or grainy picture is better than a blurry one! A lot is written about keeping the ISO low, but if the shutter speed tips into a long period, there is no value, especially in poor light (like the UK). A lot of photography books are written for bright American sunshine, which we rarely get!
One of our shutter speed tips is that exposure compensation effects shutter speed. If you are photographing something rather dark, often a slightly darker picture looks fine. If you shoot at -1 exposure compensation in Aperture priority, the camera makes the picture darker by halving the shutter speed. So you could reduce the shutter speed again by going to -1 – making the picture darker but not more grainy.
So looking at your photograph which is at F1 .8, 1/30th the second and 800 ISO. If you had increased the ISO 1600 and kept the aperture the same, the shutter speed and halve 1/60. The exposure is the same, and the picture would be the same brightness as before. if you wanted to go even faster, you could increase your ISO to 3200 and the shutter speed would go to 1/125th, but it might be a little grainy/noisy. It would still be the same exposure. If you are happy to make the picture darker, you could go to -1 exposure compensation and the shutter speed would half again to 1/250 of second.
This is assuming you are working aperture priority, if you’re working in shutter priority the camera maintains the shutter speed you’ve put in and plays with the aperture when you increase the ISO or change the exposure compensation. The effect of this might be to change the depth of field as the aperture gets smaller as you make the camera more sensitive or use a darker shot.
It’s easy really – halving and doubling the sensitivity, and keeping the hole the same size means that the shutter speed will halve and double. It’s the most useful of our shutter speed tips.