This weeks FAQ Friday post is about manual focus and the pros and cons of it. If you’ve been wondering about when is a good time to actually use manual focus, then this post is just for you. First off, manual focus mode? In the time of the latest and greatest auto-focus cameras, is the ancient manual focus mode even necessary? The short and sweet answer is a resounding YES. Read through for more details.
I was wondering if you can do a post on manual focus. My picture would be super blurry. I just want to know more what is the pros/cons using manual focus and how to use it. I usually use the auto focus>AF-area mode>single point and the picture usually turns out really nice
So what are the cons of manual focus? Well the obvious one is that is super slow. Another one is that it is prone to user-error. If your eye thinks it’s in focus, when it actually isnt… your photos will still be blurry.
What are the pros of manual focus? In certain modes, it can perform much better than auto-focus (AF) mode. It may be slow but it gives you precise control. Once you get used to manual focusing, it can actually become a life saver in certain situations.
There are certain times when auto-focus mode just slows you down. Wait… automatic focus mode slowing you down? Ironic isn’t it? Certain times when there are lots of obstruction in your frame your camera may not focus on the thing that YOU want in focus. For instance, imagine your subject in a field of tall grass. How are you going to focus on your subject moving through the grass? In auto-focus mode your camera will try to grab focus of your subject, but more often than not it will focus on the nearest subject to the lens. The remedy? Use manual focus by adjusting the focus ring on your lens and then keep the distance between you and your subject the same (read: move as your subject is moving too). Another option is a more advanced focusing feature called “AF-ON”… it is essentially manual controlled auto-focus mode. More on AF-ON later.
Another instance where manual focus outperforms auto-focus is in macro photography. When you want to get up close detail shots of bugs, flowers, jewelry etc… manual focus will be your friend. When even the slightest change of focus will shift your whole composition, manual focus is crucial. How do you make sure your manual focus is spot on? If you are lucky enough, your camera will have the “live view” feature. Once in live view mode, zoom in on the LCD to make sure your focus is spot on. Essentially, your expensive DSLR now behaves like your cheap point and shoot by using the rear LCD as a preview device to help you focus (instead of you having to view through the tiny viewfinder). What? I spent all this money on a nice DSLR and you’re saying my point and shoot can do just as well with macro shots? Well in this instance, yes… but your DSLR has a much larger sensor able to pick up much more dynamic range in light and color. However, there are photographers out there who actually do use point and shoot cameras (albeit the more expensive ones) to take their detail shots of wedding rings etc.
Another example is with night time photography. Your AF sensor generally relies on contrast difference within a certain focus point area. So at night when there is dim lighting, there may not be enough contrast… the end result? Your lens keeps hunting back and forth and finally settles on a “maybe in-focus” spot. Even if you get lucky and your camera catches focus for one shot, on your next shot you will push the shutter button half-way to focus… now it tries to refocus and you are back to the focus guessing game. What’s the answer? Manual focus of course. Use manual focus and your live-view to make sure you have precise focus. Again, if you have it on your DSLR, the more advanced AF-ON focus feature is a big help here.
Wait, you want ANOTHER example for when MF outperforms AF? How many times have you taken a portrait where the sun is behind your subject in your frame and everything turns hazy? What usually happens next? Same thing as before, your lens hunts and hunts and ends up guessing where the focus should be. What’s happening here? Just as before, your focus points are looking for differences in contrast. However, when the sun is in your frame the lens flare greatly decreases contrast and thus makes it very difficult to grab accurate focus. The sure fire way? Use manual focus to grab focus. If you MUST use AF then here’s a tip: step to the side so your subject blocks the sun, grab and lock your focus (keep shutter button half pressed)… then shift back to your original position and fully press down on the shutter to snap.
Now that I’ve mentioned quite a few instances where manual focus could give your more accurate focus, let’s talk about this “AF-ON” feature. What is it exactly? The problem with regular AF mode is that it will try to grab focus EVERY time you press your shutter button. What if you have a difficult frame and don’t want to play the focus guessing game after each frame? That’s what the AF-ON feature was made for. With the AF-ON feature turned on, the usual focusing with your shutter button (by pressing half way) is disabled, you now focus with a separate button (usually one next to your thumb). Now that you have acquired the proper focus on that difficult frame of yours, the next time you re-press your shutter button it won’t change focus at all! In fact, your shutter button only does ONE thing now, which is to snap the shutter. For example let’s take the night time photo example above. The sequence would be: get proper focus with your AF-ON button… click shutter, model reposes, click shutter, click shutter, click shutter. You’ve just taken 4 frames of the model all with proper focus instead of 4 frames of the focus guessing game each time.
The only caveat with the AF-ON button is a basic one: If your subject gets closer or further away from you… you have to refocus. Duh!! Common sense huh? In summary, the AF-ON button makes focus between each frame less of a guessing game. It is a super manual focus mode without having to touch the manual focusing rings yourself. It relies on the AF system that exists on that expensive camera of yours… instead of your eyeballs! Sounds strange huh? Not sure if your camera has the AF-ON feature? Read your manual… if your camera doesn’t blatantly have an “AF-ON” button on the back… you might be able to reassign one of the other buttons on the back (usually the “AE-L/AF-L” button. check the “controls” section on your Nikon camera menu).
I hope this post explains when and how to use manual focus for some of you out there. If you have any questions, feel free to ask below. 🙂
What is FAQ Fridays?
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