Canon 7-5D-Shutter or Aperture priority ever used for videos?

E

eco_bach

Well-known member
Ok
I'm sure this is in the noob category, but my understanding is that when shooting movies, you are either fully manual(with auto ISO) or fully automatic if you're toally unfamiliar with your camera.

But is there ever a situation when you would shoot with shutter or aperture priority?
 
It doesn't do anything to shoot Av or Tv. Your either fully manual or fully auto. Set anything other than M on the mode and your fully auto. At least on my 1DMKIV.

I tried it. I tried Tv so that I could set at 1/60 shutter and let the camera set ISO and aperture. The camera changes whatever it thinks it needs to...shutter, aperture, and ISO.

Regards,

G.
 
One thing I noticed while using M, is that whenever I zoom in, auto-exposure kicks in and changes the the brightness of the image. Is there a way to turn that off?

-Alex
 
eco_bach said:
Ok
I'm sure this is in the noob category, but my understanding is that when shooting movies, you are either fully manual(with auto ISO) or fully automatic if you're toally unfamiliar with your camera.

But is there ever a situation when you would shoot with shutter or aperture priority?
Click to expand...

In controlled shooting situations there is no reason for auto anything. Spend the time you are not on set learning your camera, and there will be no need for it to make decisions for you.

One thing I noticed while using M, is that whenever I zoom in, auto-exposure kicks in and changes the the brightness of the image. Is there a way to turn that off?

-Alex
Click to expand...

You are using a lens that isn't constant aperture through the whole zoom range, and thus the abrupt little changes in exposure as you zoom in and out. No way to fix this aside from buying a constant aperture zoom lens.
 
Even if this can be done, it's a bad idea.

First, as William pointed out, if you're in control of your shooting environment there is no need for auto-anything. The only caveat here is that, sometimes, it can be handy to let the camera auto-expose or auto-focus just to see what it says it wants, then tweak settings from there.

The other thing that's missing: what is Aperture Priority going to do for you? For one, it will shift ISO on you which can bring grain in and out. Second, and even more potentially disastrous, it's going to shift the shutter speed. This is something you do not want changed in the middle of shooting, at all.

Shutter speed is always carefully selected to craft the image. What's more, shutter speed and video on DSLR cameras make for a delicate balance. The rule is 1/60 (or if you're shooting PAL, 1/50), because your video can otherwise suffer from some nasty strobe under studio lighting. This doesn't matter under natural sunlight, but outside of that you can find yourself hosed with a shutter speed other than 1/60 or an exact multiple. Plus, the shifting of shutter speed in the middle of a shot is going to change the look of the shot in a noticeable, and not very pleasant, way... one that cannot be fixed in post.
 
William_Robinette said:
In controlled shooting situations there is no reason for auto anything. Spend the time you are not on set learning your camera, and there will be no need for it to make decisions for you.
Click to expand...

This is great advice.

Even if you're just walking around playing with your camera, you'll typically find that each new place you go to will need the exposure set, and then you should basically be good until you move to a new location. For example, if you go outdoors, you'll want to set the white balance to Daylight, and adjust your aperture and ISO settings, and then you're basically all set until you go indoors (or your subject matter or sunlight changes quite a bit).

Look at the histograms (not the picture itself) to judge exposure. After a while you'll get an intuitive feel for all of this and it will become easy.

Any automatic anything at all will cause problems on videos that will not be an issue with still pictures. This is because movies have a time component, and if exposure values are changing over time, you will watch the exposure moving around right before your eyes. With a still picture, it's a single moment in time, so you don't have any other exposures to compare it to.

Whether you are shooting live action video, stop motion animation, or landscape time lapses, manual mode is the only way to go if you want the best results.
 
C2V said:
The rule is 1/60 (or if you're shooting PAL, 1/50), because your video can otherwise suffer from some nasty strobe under studio lighting.
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I swear I read somewhere the standard was shooting w/ shutter @ 125 for 720p at least... is this false?
 
samrvogel said:
I swear I read somewhere the standard was shooting w/ shutter @ 125 for 720p at least... is this false?
Click to expand...

I've never heard that, though there are so many different bits of advice out there that contradict each other so it wouldn't surprise me. This has nothing to do with resolution and everything to do with electricity. The problem is flicker in the lighting based on the 60Hz electrical system (50Hz in PAL countries). If you're dealing with natural sunlight, there's no flicker because there's no electrical system to speak of. Once you start dealing with artificial lighting sources, you need to start worrying about the oscillation of the power system. Tungsten isn't as bad, but florescent and HMI are both terrible for flicker, on these cameras especially. So, 1/60 (or 1/50) is the safe zone, and if you need a higher shutter speed then you go with a multiple (1/120, for example).
 
Man, I never shoot A or S priority for stills, much less video... (OK, I come from a studio strobes background, but still... I never seem to fully agree with the meter...)
 
samrvogel said:
I swear I read somewhere the standard was shooting w/ shutter @ 125 for 720p at least... is this false?
Click to expand...

This is the recommended shutter speed when dealing with 720p at 60fps, which is usually when shooting for slow motion. It comes from the general rule of doubling your frame rate to get your shutter speed to get a "normal" look to the footage based on what people are used to with film. You can increase this shutter speed to frame rate ratio and movements will have less motion blur and will look more strobe like, as in Saving Private Ryan or Gladiator. You can decrease the shutter speed to frame rate ratio and there will be more blur and it will look dreamlike. Stray too far in either direction and it looks unrealistic to the viewer. So the general rule of thumb is double the frame rate. 1/50 shutter for 24/25fps, 1/60 for 30fps, and 1/125 for 60fps.

The electrical frequency concerns are a separate issue altogether and should be dealt with as such. If you have problems with lighting, change your shutter speed to compensate if need be, but the shutter speeds suggested above have to do with creating the perception of natural motion at a given frame rate.
 
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