AJ discusses using higher ISOs for landscapes and why bracketing can be a useful technique.
By Andrew James
I intend to expand on this subject in the future but the Quick Tip aspect of this short piece is really to remind you that it’s okay to shoot landscapes at higher ISOs when circumstances require it. Everything I’ve ever heard said or seen written tends to demand that when you take a landscape shot you do so at the lowest ISO that your camera has. On one level this does make sense because it will give you the best quality files possible and quite naturally you want this quality.
In many landscape situations I’d advocate the use of a tripod. This way, if you set ISO 100 and your exposure gives you something like f/16 at 1/5sec then there are no issues to worry about. Use your cable release or the self-timer to fire the shutter and all will be well. But there’s the rub:
Tripods aren’t always possible or practical and some people hate tripods (I know this applies to quite a few of you).
In recent times I’ve done quite a lot of ‘landscape’ photography from the deck of a moving boat – in Antarctica and in East Greenland. Now, this doesn’t entirely preclude the possibility of using a tripod but it does mean that even with a tripod your shutter speed needs to be higher because you are often shooting from a moving and probably vibrating platform. This fact means that long exposure photography is out! It can’t be done unless you are static. But it doesn’t mean landscape photography is impossible – even in quite challenging light conditions. I am happy to push my ISO up as far as I need it to go to get a shutter speed fast enough to handhold. What that shutter speed is depends entirely on how fast you are moving and how steady your handholding is and what lens you are using. I can drop down quite low - you'll need to experiment!
I recall having a conversation with a friend who has in the past been crowned landscape photographer of the year and he shared my view that this continual insistence for only ever shooting at ISO 100 was daft. In fact, his winning LPOTY image was shot at ISO 800. As always, it’s better to get the photo and that photo to be sharp but a bit ‘noisy’ than it is to have no noise and a blurry shot. The idea that you can only ever shoot a landscape at ISO 100 and from a tripod is just snobbery.
I would put in one caveat here and that is, shoot raw. I know you already do but when it comes to dealing with any possible noise issues arising for high ISO use, then raw is simply the best option. If the noise is more than you are prepared to accept, then you can try ‘nipping’ it out in Lightroom or whatever software you use.
When shooting high ISO landscapes (or any high ISO images for that matter), try to get your exposure accurate because the last thing you are going to want to do is rescue an underexposed photo. Why? Well because if you thought the original raw was noisy, just wait until you attempt to lighten those shadows. Things could get ugly! One way of doing this is to keep an eye on your histogram and makes sure you are using the righthand side of it where the lighter tones are. This doesn't mean all the tones should be on this side or you have to have it pushed all the way to the right, it just means that you have a good spread of tones within the image. As I've said before, there is no 'perfect' histogram shape! You can read more about Histograms here.
The other option you have is to bracket your exposures. On both Canon and Nikon you can dial in a bracket of, say three images, so that when you take the image, the camera will automatically fire off three shots of different exposures - depending on how you set it up. So for example, -1, 0, and +1. You're hedging your best here plus, as long as the shutter speed is reasonably fast and you don't move, you may well be able to blend those images together using Lightroom's HDR facility. If you are too far out of alignment it won't do it but if you're careful it is quite possible.
I can't say for every camera model but for most I've tried, make sure you are set Continuous Drive shooting (and at its fastest setting), set your bracket as you want it and then just depress the shutter button once and it will fire all three bracketed images one after the other. It won't do this if you are in Single Shot; instead you have to press the shutter button three times to get your three frames. Pressing the shutter button once and getting the sequence to fire off one after the other is much better and will help you keep things aligned.
So take a look at these four photos. All shot handheld, either from the deck of a moving boat or one on land but taken late evening. The ISOs use varied from 400 to 1600.
Any ideas which ISO is which? Nope, me neither - at least not without looking at the EXIF and I haven't processed these to take the 'noise' out. Yes, there is probably a bit of noisy stuff if you zoom in and stare long and hard at the shadows but nothing alarming. And the slowest shutter speed I used here was 1/200sec. As they were all shot on a 100-400mm lens, that's about as slow as I want to go.
And what about a bracketed, handheld, HDR shot? Well here's an iceberg landscape shot from a zodiac. With lots of complex reflections, clouds and even a bit of ripple from the boat to merge, it would have been easy for Lightroom HDR facility to reject this if the three frames weren't aligned okay. But it hasn't and this is the result. The fact the shutter speed was 1/500sec (at ISO 400) has meant that the bracketed sequence has fired very quickly using Continuous Drive shooting so there is less chance of movement messing up that alignment. Makes sense, right?
Don't throw away your tripod just yet. Use it when you can but otherwise use ISO to make sure the shutter speed is okay and keep on taking those landscape photos. Using bracketing in continuous drive will also help you ensure you get one shot that is spot on or you can look to merge the three for a well balanced final 'HDR' style photo. And as I've said before, if you don't know it's an HDR image then it's a good HDR image!