C100: Exposure question - C100II

E

ED299

Active member
Back in my still photography with film days we used to shoot for the highlights and let the shadows fall where they may. Fast forward to shooting video with the C100 MarkII and I find that approach isn't always reliable. I've been shooting outdoors in a high contrast situation where I'm unable to control anything about the lighting and am finding that my knowledge and technique are lacking a lot.

I was filming bald eagles in bright sunlight. With the pure white heads and dark backs and sides I found exposures difficult and ended up having to fix things in post. My thinking was that to keep detail in the whites I used the WFM and tried to keep the peaks at 80-90 IRE. Of course the birds did what birds do - move constantly in and out of the direct light so I ended up with a lot of variation. I did my shooting in WDR mostly and a bit in CLOG to try it out. To keep things interesting sometimes they'd land on snow and other times land on dark trees in the shadows. Typically I used ISO 850 and dialled in ND as needed.

I'm quite new to shooting with the C100. In the same situation previously with a 70D I found my white were always clipped so I wanted to avoid that with this camera. My question is how would you meter and shoot this situation? I really want to do better!

Thanks,

Ed
 
It's of course hard to say since I wasn't there. I don't know how many stops of difference there was between eagles against the sky (EV of maybe 14-15) and when they were in the shade. EV 15 corresponds to the old 'Sunny 16' rule saying that on a sunny day, front lit, you need f16 and then the same shutter as ISO:

f16, 1/100, ISO100
f16, 1/400, ISO400
f8, 1/800, ISO200

They are all EV 15. On an overcast day you're looking at EV 11. One EV (Exposure Value) is one stop.

People don't really talk about these anymore now that we have sophisticated light meters built into our cameras, but they are surprisingly accurate. And stuff like this—what I'm trying to get at is manual metering—can be a good friend in mixed/varying lighting. Another example would be a concert or theatrical performance with constantly changing lights: you'll need to check the split between the highlights and shadows, go all manual and trust your technique.

Generally, I think exposing for the (hi)light is a good idea. Shadows dropping into black only adds mood and dimension. Assuming of course, that your subject actually IS in the light =) The next time you do this at a concert and set the exposure for that cool spotlight that keeps circling back to the subject, you can bet that a few frames will be taken just a second too early or too late. Part of the game. But having set the exposure once and for all, you can focus solely on getting that critical moment.
 
AndreeOnline,

Thanks for the reminder about the sunny 16 rule. It's always good for me to go back to the basics. It does bring up a question though. In the situation I've been describing I've been shooting at the native ISO of 850. Aside from getting a better image from the camera, that also gives me some working room in the dark shadows. I think an EV of 14 or so is probably right. If I use the reciprocal of my ISO at f16 that gives me a pretty fast shutter speed. I thought as a guideline the recommended shutter speed for general video were typically the reciprocal of the fps rate. Since I shoot the birds at 60 fps that suggests 1/60 approximately. I usually shoot at 1/120. Wouldn't going to a higher shutter speed (i.e. 3 stops to 1/880) have an effect on my video, making it more jerky?
 
Thanks PedroAquiles, I'll try that. I haven't been using zebras much since I tend to watch my WFM. I suppose the answer may be that I just need to be faster on my aperture readjustment as the situation changes. I find that tough because things happen so fast and despite years of observing these birds it's nearly impossible to predict what will happen next.
 
The Waveform are a great tool, but for run and gun the zebras work better for me. I just use the 90% because the 70% rule for the skin tones sometimes give me bad results from diferente skin tones and indoor and direct sun light
 
The rule is usually twice that of the FPS to keep it at a 180 degree shutter. That will give you that natural motion and hide the frames. If you go the same as the FPS you will end up with too much blur and your images will not be sharp enough. Now if you go more than twice the FPS it will make the image sharper but it will start to get "steppy". Which can sometimes be good though. But it all depends on the effect you are looking for.

ED299 said:
AndreeOnline,

Thanks for the reminder about the sunny 16 rule. It's always good for me to go back to the basics. It does bring up a question though. In the situation I've been describing I've been shooting at the native ISO of 850. Aside from getting a better image from the camera, that also gives me some working room in the dark shadows. I think an EV of 14 or so is probably right. If I use the reciprocal of my ISO at f16 that gives me a pretty fast shutter speed. I thought as a guideline the recommended shutter speed for general video were typically the reciprocal of the fps rate. Since I shoot the birds at 60 fps that suggests 1/60 approximately. I usually shoot at 1/120. Wouldn't going to a higher shutter speed (i.e. 3 stops to 1/880) have an effect on my video, making it more jerky?
Click to expand...
 
ED299 said:
It does bring up a question though. In the situation I've been describing I've been shooting at the native ISO of 850. Aside from getting a better image from the camera, that also gives me some working room in the dark shadows. I think an EV of 14 or so is probably right. If I use the reciprocal of my ISO at f16 that gives me a pretty fast shutter speed. I thought as a guideline the recommended shutter speed for general video were typically the reciprocal of the fps rate. Since I shoot the birds at 60 fps that suggests 1/60 approximately. I usually shoot at 1/120. Wouldn't going to a higher shutter speed (i.e. 3 stops to 1/880) have an effect on my video, making it more jerky?
Click to expand...

As mentioned above, the 'normal' shutter for 60fps would be 1/120. With an ISO of aprox 800 and f16, you are right that you need an ND0.9 (3 stops) to get back to EV14. I would personally go for more like f8 and ND1.5 (5 stops). Lenses perform better below f11.

And again: the tip of honing in on a certain EV is primarily in situations where the light levels change quite a bit. In other words, in a situation where you don't have time to check a waveform or other tools. And of course, once you expose for the light, you need to grab the frames when the subject is actually lit by the light that's coming and going. But those are also likely the best frames, as subjects in shadow become very flat.

PS. If you want the greatest fidelity in the shadows you need to lower the ISO. High ISOs protect the highlights (measured in number of stops relative to 18% gray). It's a bit counter intuitive but…
 
Thanks for your explanation of the way you use zebras PedroAquiles. I've played with the settings and used them a bit but haven't found them as easy as the WFM. I don't do run and gun and usually have time to get set up but then the 'talent' always provides me with the problems I described.
 
AndreeOnline, So far I've been sticking to ISO 850 as it's supposed to be the 'native ISO' for the Mark II. I read somewhere that going below this value tends not to give as good an image but I've never tested this myself. In your experience would there be much of an IQ drop or am I worrying about nothing? So far I've been using the ND to deal with excessive light and leaving my ISO alone.

Thanks,

Ed
 
Yes, it's totally fine to leave the ISO at 850. You can treat it as a fixed ISO camera and work like that.

ISO 850 is recommended because it's the LOWEST ISO that gives you the maximum amount of highlight protection that the camera offers: 5.3 stops. Any higher ISO gives you the same 5.3 stops above middle gray, but once you lower the ISO your available stops will shift to the shadows.

At ISO 400 you have 4.2 stops above middle gray, but you have won an extra stop below. So if you're shooting indoors with controlled lighting you might find reason to spend your stops in the shadows and try to get as clean images as possible.

Options at your disposal.
 
There was quite a bit of technical discussion after the release of the original C300 and C100. Obviously, that is a while back now and much of that is buried deep in the forum.

Canon has several 'white papers' with technical information on the S35 sensor and Canon Log. They are not as heavy reading as one might expect.
 
You must log in or register to reply here.
Back
Top