What advantages does manual mode have over aperture priority mode?

Question

I'm wondering what are the most compelling reasons to switch to manual mode on my DSLR. I mostly just use aperture priority mode so I have good control over the depth of field combined with an awareness of the shutter speed that goes with it. My photography is mostly done wandering about with camera in hand, or occasionally on a tripod. I don't do studio photography and I just use the natural light.

I did learn how to take photos manually (with an Olympus OM-1) so I know how to do it, but I enjoy the extra convenience of aperture mode, particularly being able to take the photo quickly and capturing the moment rather than fiddling with dials and missing the shot.

So what would be some key advantages of using manual mode for my sort of photography that are worth the (small amount of) extra hassle involved?

And do you have any tips to minimise the downside (other than practicing to be quick)?

Answer 1

I typically use aperture priority as well, but I also work a fair bit in manual mode. The typical case for me is if I am in an environment where the lighting situation is quite static, but the subject may have a lot of contrast. Here I switch to manual mode and shoot a few test frames to pinpoint the exposure (typically I try to spot meter on a white surface, and then overexpose that reading by 1.5-2 steps as a first guess).

The main advantage is that you are in full control, and the camera will not be "fooled" by unexpected contrasts in the frame. The downside is that it is a bit slower to change exposure in case the lighting situation changes.

Answer 2

Manual mode can give you more consistent metering when you're taking several photos in a scene. For example, suppose that you're photographing a person whose body is fully illuminated but whose face is partly in shade. If you take a full-body image and then a head and shoulders portrait, the metering could end up different because the percentage of the frame that its brightly illuminated will change. But if you're in manual mode, you can select the "right" exposure and then both will be consistent.

Answer 3

Aperture priority can be ideal for a walkaround mode, especially when combined with exposure compensation.

I only tend to flip to manual mode when I'm shooting a lot with the same lighting, or rapidly changing lighting -- so things like food photography (where dark meat or glistening glazes can trick the metering), or fireworks where the automatic metering may pick up a previous shot, or not understand why you're taking a photo of a blank scene.

Answer 4

The biggest benefit I can think of is consistency between shots.

This is normally not much of an issue, but when you are wanting to capture the changing light in a scene for time lapse or do panorama stitching the consistency becomes really important.

Answer 5

Sometimes the amount of exposure compensation available (ie +/- 2 stops) in Aperture priority mode might simply not be enough.

Answer 6

I prefer manual mode for a few areas:

1) stage fotografie. Usually, on stages the light has very high contrast. Any automatic mode most of the time will blow the faces because it is trying to get all the dark background to 18% grey.

2) panoramic fotos. Having inconsistent exposure for the frames is a real pain in stitching them together, so I'll use manual mode for these.

3) other high contrast scenes (person in front of window). The automatic mode does not know if I want the background properly exposed or the person in front of it, usually the person is too dark and the window too light. Using manual mode I decide which one is important for me.

4) manual wireless flash. I use non-TTL strobist flash a lot, and in these cases the automatic modes do not know about the extra light from the flash, so I need to go manual.

I use automatic modes when I just want to make a quick picture to show on twitpic or facebook.

Answer 7

If your subjects stay the same but your background changes in luminosity greatly. I was shooting sports indoor with a door to the outside open, so my subjects would have gotten real dark if they went by of the door.

Also, if you want to maintain a certain shutter speed (freeze action) and aperture (for subject isolation), and you don't have TAv mode or equivalent, you would use manual mode. You can increase ISO through software (essentially it is the same as hardware ISO), although if you need to change the ISO significantly, you need to use RAW or the JPEG tone curve will eat the data in the shadows.

Manual everything makes it a lot easier if you are doing shoots for stuff like events, sports, portraits, etc. Often, you want to post-process the first picture and copy all of the settings to the following ones. If your camera is changing the exposure or WB between shots, it makes it harder.

Lastly, manual mode is great for flash photography when and mixing ambient with flash. There are some cases where aperture priority can work better, with auto ISO off.

Answer 8

Reading through this article about the zone system (found from this answer) made me see how using the zone system would be useful and require manual mode. Basically using a spot meter (for me, the one built into the camera) to find the exposure for the part of the photo you want to appear with a particular brightness, and setting the exposure accordingly.

Of course, you could make a fair guess and use exposure compensation. Or suck it and see with viewing the result on the back of the camera, adjusting and retaking the photo (for static subjects). But that did seem interesting.

Answer 9

The main reason I switch into manual mode is to create shots that I know aperture priority won't do.

Silhouettes or intentionally over/under exposed shots for example. Aperture priority is great for 'normal' or 'properly exposed' shots, but not so great once you want to start experimenting a bit.

A recent favourite of mine is a very high contrast shot I took from inside a tunnel looking out into the bright sunlight. This was well outside what the aperture priority mode on my Canon 400D would be happy doing.

Answer 10

As well as the reasons of consistency between shots (either for high-contrast photos in fairly consistent lighting or for stitching shots together), I also use Manual when I'm using a flash indoors.

Might be just due to lack of effort to learn how to shoot Av + flash on my part, but I find it much easier just setting it in full manual with f/4, 1/100 ISO 400 (or thereabouts) and letting the E-TTL flash metering do its thing.

(this is for shooting events indoors)

I also find that shooting indoors in a location with large windows makes it worth being in Manual mode as well. Otherwise whenever there's a window in the frame, you'll have the meter under-expose (in the day) or over-expose (at night) depending on the brightness outside. This seems to be more important with wider lenses (with a long telephoto I guess you're getting much more subject than background anyway most of the time, so the frame is more likely to be more consistent).

Answer 11

Full manual control is also necessary where you are taking shots, for example inside a building, where you perhaps need to bracket exposures for HDR where there is a high dynamic range, or where there is just inadequate lighting. In these circumstances exposures longer than 30s may very well be needed, and most cameras under aperature priority will only time a shot for a maximum of 30s. Use manual exposure and the bulb setting, using a timing device to time the shot.

Answer 12

Manual exposure is necessary whenever you are using neutral density filters, or any other filters which significantly darken or limit the amount of light coming into the sensor. You don't need to set manually with a polarizer or other filters which only lessen ight by a stop or so. But If you don't set exposure yourself with darker ND filters Ii.e. Lee's Big Stopper), the camera will almost always not correctly compensate, and it's difficult to gain control over any changes you make to the settings.