How much can you overexpose/underexpose on the 7d?
- Thread starter leaftors
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morgan_moore
Major Contributor
not at all
get it perfect in camera and it can look fine
get it perfect in camera and it can look fine
This is technical question and its answered in technical reviews of 7D, you should not look at cinematography like that, its not math, sometimes you want underexposed and sometimes you want high key, it really depends.Cinematography is not about catching all dark and bright areas in the frame without losing them, its about creating the mood, you might not understand it now like i did 2 years ago but you will understand it later when your footage would look bad cause you would have flat image and would want to have no shadows and no clipped highlights, then you realize your footage looks crap cause theres no mood, create shadows and dont think so much about technical exposing and not losing any detail in camera, thres no magic, how you see the pic in camera is what you would get, you can bump up gamma sometimes but that would give you grainy picture with codec artifacts.Test, test and test your camera so you wont fail in front of 10 people on the set waiting.
I believe what the OP is asking is how dark/bright (in terms of stops) he can light with the 7D before under/over-exposing.
Simple answer - Not much. The highlight and shadow detail in the 7D is awful and even if you manage to balance it right in camera you are bound to kill most of that detail grading in post (I usually advocate nailing it straight in the camera when shooting with low-end DSLR's)
Simple answer - Not much. The highlight and shadow detail in the 7D is awful and even if you manage to balance it right in camera you are bound to kill most of that detail grading in post (I usually advocate nailing it straight in the camera when shooting with low-end DSLR's)
morgan_moore
Major Contributor
Exactly
starcentral
Veteran
Taking an objective look at some of the posts, there are instances where you can't or wouldn't want to nail it in camera.
It could be to gain and extra stop of exposure or to leave you with more higher end range for smoother highlights. For smooth highlights you need to shoot underexposed knowing you will bring mid-levels back to where you wanted them in post. Other times you might just want an extra stop without doubling your ISO so you can underexpose by one stop and bring it up in post.
There are tradeoffs to it for sure but you can always use an external recording device to get higher bit-rates and bit-depth which would only improve pushing the exposure in post later on.
As for pushing native footage from the 7D if you light the entire scene with a good spread of your darks to lights within 5-7 stops it will leave you plenty of room in post to do some decent grading and move your mid-tones around by 1-2 stops since you will have enough separation from your darks and highlights. In my opinion blacks are often crushed, mid tones are shifted, and highlights are compressed to give a nice roll-off.
Overexposure? I would just avoid that if possible but generally pulling an image in post increases the signal-to-noise ratio so in fact you can end up with a more noise free image but at the serious cost of blowing your whites in camera. On a low contrast scene you might be okay.
I think lighting is all about math. For cinematic productions there isn't a time where I'm not conscious of the entire scene tonal range and what I will be recording. Knowing your scene range will allow you to recreate it, and allow more working room in post.
If you're really keen on using a light meter check out some of the posts in my blog and you can see how I've been putting one to good use.
It could be to gain and extra stop of exposure or to leave you with more higher end range for smoother highlights. For smooth highlights you need to shoot underexposed knowing you will bring mid-levels back to where you wanted them in post. Other times you might just want an extra stop without doubling your ISO so you can underexpose by one stop and bring it up in post.
There are tradeoffs to it for sure but you can always use an external recording device to get higher bit-rates and bit-depth which would only improve pushing the exposure in post later on.
As for pushing native footage from the 7D if you light the entire scene with a good spread of your darks to lights within 5-7 stops it will leave you plenty of room in post to do some decent grading and move your mid-tones around by 1-2 stops since you will have enough separation from your darks and highlights. In my opinion blacks are often crushed, mid tones are shifted, and highlights are compressed to give a nice roll-off.
Overexposure? I would just avoid that if possible but generally pulling an image in post increases the signal-to-noise ratio so in fact you can end up with a more noise free image but at the serious cost of blowing your whites in camera. On a low contrast scene you might be okay.
I think lighting is all about math. For cinematic productions there isn't a time where I'm not conscious of the entire scene tonal range and what I will be recording. Knowing your scene range will allow you to recreate it, and allow more working room in post.
If you're really keen on using a light meter check out some of the posts in my blog and you can see how I've been putting one to good use.
j1clark@ucsd.edu
Veteran
With any 'digital' camera at the moment, one can probably 'live' with 1-2 stops under exposure, and post processing 'boost' in contrast. "Overexposure" results in loss of information in the high values of the image, and so, can not be compensated for at all... therefore... one does not 'overexpose' digital cameras. However, even with 'under exposure' and contrast increase compensation, DSLRs will begin to show artifacts such as 'banding' in smooth gradient areas of an image, very quickly, so the use of contrast enhancement is not a cure all for image problems.
The terms over/under exposure are hold overs from the olden days of negatives, where one could 'over expose' the negative, and with processing (post processing...) of the negative compensate for that 'over exposure'.
There are situations where one can 'live' with areas of the image being 'blown out', that is 'over exposed', however, those situations are limited to 'windows', 'direct light sources', or specular highlights. In any case, most people tend to use various methods to avoid even these situations... such as treating the windows to bring down the values from 'blank white', avoiding 'direct light sources', and making any specular highly 'very small'...
Yeah, the problem is if you over-expose, then that roll-off from 99% to blown out goes really abrupt. if you can keep your highlights under, it will be smoother.
Of course, underexposing with the dslr codecs is not great either, but with some color-correction and a program like neat video to clean it up, you can get quite decent results.
Of course, underexposing with the dslr codecs is not great either, but with some color-correction and a program like neat video to clean it up, you can get quite decent results.
starcentral
Veteran
My best advise is to always get your skin exposure the same from shot to shot, scene to scene, day to day, month to month - and do whatever you can to control the lighting in the rest of the scene.
The footage will edit together better and less grading will be needed to move around the mid-tones leaving some room with inferior codecs to crush blacks a bit and play with color saturation and other color balancing. Far too many people swear you need 10-bit and super duper codecs to grade footage but they are indeed wrong. If it is shot well and consistently a lot is actually possible.
All my work from this year was graded s*%tty 8-bit 420 footage and people were convinced I was shooting RAW or SLOG... nope. Just exposing images properly, consistently and diligently.
Lighting (and lighting control) is everything. Everything else is bulls*%t.
The footage will edit together better and less grading will be needed to move around the mid-tones leaving some room with inferior codecs to crush blacks a bit and play with color saturation and other color balancing. Far too many people swear you need 10-bit and super duper codecs to grade footage but they are indeed wrong. If it is shot well and consistently a lot is actually possible.
All my work from this year was graded s*%tty 8-bit 420 footage and people were convinced I was shooting RAW or SLOG... nope. Just exposing images properly, consistently and diligently.
Lighting (and lighting control) is everything. Everything else is bulls*%t.
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