luminence and zebra's

HDR(Video) |------------------| Stops
Film |--------------------| Stops
Video |----------| Stops

You have less dynamic range for video than you do in film or HDR(Video). Compose, light and expose accordingly.
 
HDR stands for ??
Compose and light are parameters you can not controll always. For instance a wide shot of a dark forground (dark mountain) against a light background, you can not fill in the mountain with a 1000 watt light bulb over a distance of miles.


Erik Olson said:
HDR(Video) |------------------| Stops
Film |--------------------| Stops
Video |----------| Stops

You have less dynamic range for video than you do in film or HDR(Video). Compose, light and expose accordingly.
Click to expand...
 
HDRv is an important emerging technology that mimics the old photographic process called "bracketing". Two (or possibly more) imagers / cameras are simultaneously / near simultanously exposing for two different exposures (e.g., highlights safe, detail in shadow areas). The resulting two images are recombined in real time or in post to give one very wide, flat exposure. These images can be manipulated to a huge degree in post, where conventionally taken video does not lend itself to this because of it's lower, more contrasty dynamic range.

http://en.wikipedia.org/wiki/High_dynamic_range_imaging
http://vimeo.com/14821961
http://vimeo.com/13966986

A graduated ND filter will do plenty to correct over-exposed skies against a darker scene below the horizon. Photographers have been solving that problem through various techniques for a long, long time.
 
Cees Mutsaers said:
I don't think you can callibrate the EVF on the HPX300 at least i don't know how to that with this cam. If you put your second zebra at 100 % when it becomes visible it can have any value above 100% so you keep the iris openend so the second zebra is just not visible in the sky right ? However when you do that the rest of the frame will be way underexposed (in 9 of the 10 cases) and the rest of the frame is the interesting part. So I think that the only solution is a gradient ND when shooting scenery or extra light when you shoot people in front of a sky as background as suggested by the other members in this thread.
Click to expand...

I don't mean calibrate the way you would a broadcast monitor. I mean adjust it so it looks like what you're seeing with the naked eye. Anything over 100 will clip (although it's higher with some cameras). You're choice with a sky is to overexpose the sky to retain detail elsewhere, or expose the sky correctly and underexpose the rest, simple as that. A gradient ND filter will help a lot. My solution is to not put people in a shot with the sky in the background unless I have a light or reflector on them.
Ed
 
Cees Im going to try and simplify some things here, and Im going to talk very generally.

So generally, set your upper zebra to 95 - when exposing on an exterior wide shot roll your aperture down slightly so the upper zebra just touches it.

If you have a person in shot set your lower zebra to around 60-65, zoom in on the person and make sure generally he/she is in that area. As Eric said small areas outside that are fine - get the majority in there.

An easy way to get reasonable exposure between the two is to use the sun as backlight out of frame around the 10 o'clock position on the person. Then use a reflector / or bounce board as a key / fill.

As I said this is generally, but its not always possible to get the sun at that position because your shooting amongst tall buildings, trees etc. To make a shot pleasing what your looking for is a well balanced shot. So what that means is basically if you look at a greyscale chart, you want to try to get as many of those levels in the shot as you can. If you have an area at 80 ire and the background at 10 ire and NOTHING in between, the shot generally will have a displeasing aesthetic. BUT BUT BUT, it depends what youre shooting. If you were to apply this greyscale example to every shot regardless of what your shooting youll quickly find it doesnt suit everything. But its a start point to expand upon. For a beautiful scenery shot it would work, but for a dark thriller for example it may not, but as you go along you will understand how much effect the style your shooting for varies this.
 
Hmm I know how to light a person with key/fill-in/back and background lights but I am talking about an outdoor wide shot without people in the shot just scenery, focus is infinity, bright sky etc. etc. and I think the only solution like one of the members said already is a gradient ND filter.
 
Grad nd is your best option. Second best is to expose two different shots (for the sky and for the foreground) on a locked down camera. Composit them in post.


Jason
 
You must log in or register to reply here.
Back
Top