when to use manual (M) mode...?

[Lycoming]

Hello all,

I got into DSLR back in august and when I started I jumped right into aperature and shutter priority modes. I've yet to take a pic in auto mode, but also in manual, which I can't figure out.

In aperature mode, I'll pick the aperature I want and then the camera will tell me what shutter speed I need, and the same with shutter mode.

In manual though, won't the exact same thing happen only by my own selection? I mean there is the indicator that tells me whether the image is going to be exposed properly. So once I pick my aperature then I just have to dial in the appropriate shutter speed, that the camera would be giving me anyways. I already control all the ISO and WB settings in those 2 modes. When is manual mode useful? I feel like it's telling me something I already know.

Thanks!

[Niresangwa]

The camera is always going to pick the settings for the ideal exposure which you don't always want when trying to create something. An example for me was an engagement shoot this past weekend...

a train was passing by the location and i wanted to include the motion blur behind the couple. without being in manual, I couldn't have made the adjustments required for the subjects being covered with off-camera lighting, as well as make use of the motion of the train behind them.

there are a myriad of situations the camera can't take into account for creative shots - all it figures out is the 'correct' exposure. in reality, that's just a starting point from where you adjust certain settings that will get you to what you actually 'see' in your mind when putting the shot together.

If you're in Av or Tv, you'll just be working against the camera in those situations, and in P it's going to be practically impossible to do some of the things you'll need to do.

Having said that, when you're still in the learning phase, (ie trying to understand the interplay in garnering the correct exposure) the auto- and semi-auto modes can be useful in figuring out why the camera selected the settings it did, and what the result was...

...once you have a solid grip on exposure and manipulating it, you can start to use that knowledge to create things that transcend 'good' exposure.

AV, TV and sometimes P have their place, but again you should be using them because you know why you're using them (you know you need a wide aperture for low light, or know you need high SS to stop motion), not because you don't know what the effect of the settings will be.

[Jim Bryant]

Use manual mode when the lighting is consistant. You can also set your shutter speed to a desired setting and change the f-stop. I use manual when shooting sports at night and inside where the light is not constantly changing. You could also do that for studio portraits. As a matteer of fact you can shoot manual in all applications in photography.

[andyw]

"when to use manual (M) mode...?"

When you need to (want to) override what the camera "tells" you is the best exposure.

There are a thousand and one situations where this may be the case from tricky lighting situations through to long exposures and studio work using studio lights.

The exposure that your camera gives you is (depending on how you have it set up) generally a "centre weighted" average of the whole scene. This is often not the best for the actual picture and you are better going onto manual to get the exposure YOU want and not what the camera tells you.

[Lycoming]

So manual is used if you purposefully do not want the proper exposure on a photo? When would you ever want the wrong exposure? And couldn't this just be compensated for by adjusting the EV +- of the shot?

[zona5101]

Originally Posted by Lycoming

So manual is used if you purposefully do not want the proper exposure on a photo? When would you ever want the wrong exposure? And couldn't this just be compensated for by adjusting the EV +- of the shot?

Hopefully you are smarter than your camera and not the other way around It's your camera that is wrong and you adjust in manual to get the right exposure...

Yes, adjusting the exposure compensation will land you in the same spot althought you maybe limited in the number of stops you can vary when using your comp dial.

[dcclark]

Your camera's meter can be tricked. You, the human, know what you want. The camera's meter can only guess. They're usually quite good, but not perfect. If you want to show the one lit object in a dark room, you'll have to mess with the exposure manually -- your camera will go crazy trying to expose everything perfectly. That's a reason to use manual mode: when you know what you want, and your camera isn't giving it to you by default.

[RichardTaylor]

I use manual when I want total control over the exposure.
Sometimes you do not have time to dial in exposure compensationif you want to catch the action.

Some examples:

(1) Macro with a off camera external flash.
Here I set the camera to max synch speed and a fairly small aperture to give me a bit of DOF (and kill the ambient light).
Lens was set to manual focus and minimum focussing distance.
Hand held.
Flash power was adjusted to give me a good histogram on a couple of test shots before approaching the the bugs.
All I had to do was to move in until the frame was filled and the bugs looked sharp, and press the shutter button.
.


Camera Canon EOS 350D Digital + Tokina 100mm F2.8 macro lens
Exposure 0.005 sec (1/200)
Aperture f/16.0
Focal Length 100 mm
ISO Speed 400
Exposure Bias 0 EV
Flash On, Fired


(2) Sometimes the subjects move so fast that you have to catch them on the fly and will not have have time to dial; in exposure compensation.
Sometimes the lighting can be pretty awful as well, like the dappled light in amongst the tree.
Similar set up to above except I was using autofocus (centre point only active) and the external flash was camera mounted.
I was using a 100-400 lens.


Camera Canon EOS 40D + Canon 100-400 lens.
Exposure 0.004 sec
(1/250)
Aperture f/16.0
Focal Length 300 mm
ISO Speed 400
Exposure Bias 0 EV
Flash On, Fired

(3) Night shots where the combintion of lights and dark sky can really fool the meter. Sometimes exposure compensation is not enough (the number of stops you can dial in is limited)
Hand held.

Camera Canon EOS 5D + Canon 35mm F2 Lens.
Exposure 0.04 sec (1/25)
Aperture f/2.0
Focal Length 35 mm
ISO Speed 3200
Exposure Bias 0 EV
Flash Off, Did not fire

(4) Sometimes you will not know when and where the action will happen. Here I was basically shooting into the sun over an arc of 90 degrees. The subjects, cars, could be any colour in the rainbow.
I metered off a neutral are of the track and manually set my exposure.

You don't have time to be turning knobs & pressing buttons for some shots.
You only have time to focus (Auto) & take the picture.



Camera Canon EOS 40D
Exposure 0.003 sec (1/400)
Aperture f/11.0
Focal Length 400 mm
ISO Speed 200
Exposure Bias 0 EV

---------------------------------------
Under normal circumstances, depending on what I am trying to achieve, I either use shutter priority or aperture priority, sometimes with exposure compensation dialed in.

[jml79]

I use M most when I am lighting the picture. Actually I have to use M when I am using off camera flash. The camera can handle flash using TTL with one flash attached to the camera (there are exceptions that can do more) but when using manual strobes either studio or speedflash I have to do all of the work. I also use M for night and low light photography.

For most daylight work I just us S or A plus EV comp depending on the situation. I am constantly adjusting the EV comp, especially in winter with snow around.

[RichardTaylor]

Just a bit more.
Pics are from the weekend.

This is what happens when you don't shoot manual.
Weather was overcast (it was showery) and the cars had their lights on)

I was shooting in shutter priority. Pics have not been PP'd,except for resizing.
(1) The headlights are not shinning into the lens.


Exposure 0.003 sec (1/400)
Aperture f/8.0
Focal Length 285 mm
ISO Speed 800
Exposure Bias -1/3 EV
Flash Off, Did not fire

(2) A second or two latter the headlights are shunning straight into the lens casing a lot smaller aperture to be selected. .

Camera Canon EOS 40D
Exposure 0.003 sec (1/400)
Aperture f/13.0
Focal Length 285 mm
ISO Speed 800
Exposure Bias -1/3 EV
Flash Off, Did not fire


Here, around dawn, I was using manual exposure and exposing for the ambient light with a slightly reduced exposure to preserve the "atmosphere". I wasn't worried about blowing out the headlights.

(3) The pic has had a fair bit of PPing from the original RAW file..


Camera Canon EOS 40D
Exposure 0.003 sec (1/320)
Aperture f/5.6
Focal Length 235 mm
ISO Speed 3200
Exposure Bias 0 EV
Flash Off, Did not fire