Using prime lenses to shoot CU, MS, etc?

MatthewC

MatthewC

Well-known member
I've got a bunch of Nikon primes for my Letus Extreme. I've got an indie short coming up that I'll be shooting in the woods. I'm hoping to mainly stick between my 50mm f/1.4 and my 85mm f/1.8 for my MS/CU. I've also got a 120mm f/2.8, but I'd like to stay away from it as I won't have the latitude if I need it to go brither. Feature films, TV shows, they aren't ALWAYS switching to a longer lense between MS/CU are they? They sometimes use a 50mm for MS or whatever, then move closer and shoot a MCU, but because they've moved closer the DOF is shallower and the BG has more Boken than the MS, so it doesn't distract the viewer, correct? The reason I ask is I might need all the light I can get, but I don't want to open the lense all the way up either, other my DOF will be too shallow. I'm just wondering the proper technique and how versatile it can be, or if its standard to switch to a longer lense anyways to make sure my background definitely doesn't look to similiar between the focal lengths.
Looking forward to any advice, thanks!
 
Greatly depends on the zoom. An Angenieux zoom or Panavision zoom will make your Nikon prime seem crappy. But they don't come cheap.
 
MatthewC said:
I've got a bunch of Nikon primes for my Letus Extreme. I've got an indie short coming up that I'll be shooting in the woods. I'm hoping to mainly stick between my 50mm f/1.4 and my 85mm f/1.8 for my MS/CU. I've also got a 120mm f/2.8, but I'd like to stay away from it as I won't have the latitude if I need it to go brither.
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A slower speed lens won't effect the latitude of the sensor, unless you really don't have the proper exposure. You might mean dynamic range. Dynamic range (in motion picture terms) is the ability to push or pull the exposure of an image in processing, telecine, or DI and still get an acceptable image. It's the amount of play you have with an exposure after the fact. Dynamic range is still king in the film world... I've seen top industry DP's push a film three stops before getting unacceptable results. I've yet to see a digital camera that can be pushed three stops in post with similar performance. You just can't beat the information recorded in celluloid. However, raw formats have a great amount of dynamic range in digital land. People are pushing RedMX cameras for one, one and a half, and sometimes two stops with good results. (ie shooting 1000 iso on RedMX is about 1.5 stops, 1280 would be two stops)

Latitude, on the other hand, is simply the range of exposure values a sensor can record from black shadow to blown out highlights. Some cameras can take a large range and some take a smaller.

MatthewC said:
Feature films, TV shows, they aren't ALWAYS switching to a longer lense between MS/CU are they? They sometimes use a 50mm for MS or whatever, then move closer and shoot a MCU, but because they've moved closer the DOF is shallower and the BG has more Boken than the MS, so it doesn't distract the viewer, correct? The reason I ask is I might need all the light I can get, but I don't want to open the lense all the way up either, other my DOF will be too shallow. I'm just wondering the proper technique and how versatile it can be, or if its standard to switch to a longer lense anyways to make sure my background definitely doesn't look to similiar between the focal lengths.
Looking forward to any advice, thanks!
Click to expand...

I'm a bit confused. You said earlier (from how I interpreted your statement) that you don't want the F/2.8 lens, because it is too slow and you can't push the exposure in post with good results (dynamic range). However you now say you don't want to be wide open on aperture. If using F/1.4 or F/1.8 lenses these two criteria only leave shooting at a F/2 an option (it's between the F/1.4 and F/2.8. If you think wide open at F/1.4 or F/1.8 is to shallow... you'll probably think a F/2 too shallow as well.

Another thing to remember is magnification. Close ups will almost always have shallower DoF... despite whether or not you switch focal lengths or move the camera. The three things that determine DoF is camera to subject distance, focal length, and aperture. If you keep the same F-stop on the camera, you can do either one of two things:

1) Use a 50mm on the Medium and switch to a 100mm for the CU... effectively making the DoF shallower because of the longer lens.

2) Use a 50mm on the Medium and move the camera forward, halving the distance between camera and subject... effectively making the DoF shallower because of the subject to camera distance decrease.

You'll see, if using a DoF calculator, these two options decrease the DoF by almost exactly the same amount. The difference is practically negligible.

But this is in the PHYSICS of the image. The actuality.... Not what it looks like.

The difference is this: The CU shot that uses the 100mm will have almost the same DoF as the CU shot using the 50mm but (half the distance) closer to subject... however the shot with the 100mm lens will magnify the background compared to the 50mm lens that is half the distance closer to the subject. Thus the circles of confusion will be larger on the screen!

So despite the DoF being almost exact, one background will be more magnified making the out of focus shapes (bokeh) larger on screen.

This is a give and take with composition. If you don't mind showing less background because of the magnification and you want large out of focus elements, a long lens is better. If you want to make the out of focus elements not so obvious, and you don't mind showing lots of the background in the shot, use a wide lens very close to the actor. Just remember that at a certain point (I've found it to be 25mm or less) getting very close to the actor will result in some facial feature distortion. For better or for worse.
 
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Ryan Patrick O'Hara said:
A slower speed lens won't effect the latitude of the sensor, unless you really don't have the proper exposure. You might mean dynamic range. Dynamic range (in motion picture terms) is the ability to push or pull the exposure of an image in processing, telecine, or DI and still get an acceptable image. It's the amount of play you have with an exposure after the fact. Dynamic range is still king in the film world... I've seen top industry DP's push a film three stops before getting unacceptable results. I've yet to see a digital camera that can be pushed three stops in post with similar performance. You just can't beat the information recorded in celluloid. However, raw formats have a great amount of dynamic range in digital land. People are pushing RedMX cameras for one, one and a half, and sometimes two stops with good results. (ie shooting 1000 iso on RedMX is about 1.5 stops, 1280 would be two stops)

Latitude, on the other hand, is simply the range of exposure values a sensor can record from black shadow to blown out highlights. Some cameras can take a large range and some take a smaller.



I'm a bit confused. You said earlier (from how I interpreted your statement) that you don't want the F/2.8 lens, because it is too slow and you can't push the exposure in post with good results (dynamic range). However you now say you don't want to be wide open on aperture. If using F/1.4 or F/1.8 lenses these two criteria only leave shooting at a F/2 an option (it's between the F/1.4 and F/2.8. If you think wide open at F/1.4 or F/1.8 is to shallow... you'll probably think a F/2 too shallow as well.

Another thing to remember is magnification. Close ups will almost always have shallower DoF... despite whether or not you switch focal lengths or move the camera. The three things that determine DoF is camera to subject distance, focal length, and aperture. If you keep the same F-stop on the camera, you can do either one of two things:

1) Use a 50mm on the Medium and switch to a 100mm for the CU... effectively making the DoF shallower because of the longer lens.

2) Use a 50mm on the Medium and move the camera forward, halving the distance between camera and subject... effectively making the DoF shallower because of the subject to camera distance decrease.

You'll see, if using a DoF calculator, these two options decrease the DoF by almost exactly the same amount. The difference is practically negligible.

But this is in the PHYSICS of the image. The actuality.... Not what it looks like.

The difference is this: The CU shot that uses the 100mm will have almost the same DoF as the CU shot using the 50mm but (half the distance) closer to subject... however the shot with the 100mm lens will magnify the background compared to the 50mm lens that is half the distance closer to the subject. Thus the circles of confusion will be larger on the screen!

So despite the DoF being almost exact, one background will be more magnified making the out of focus shapes (bokeh) larger on screen.

This is a give and take with composition. If you don't mind showing less background because of the magnification and you want large out of focus elements, a long lens is better. If you want to make the out of focus elements not so obvious, and you don't mind showing lots of the background in the shot, use a wide lens very close to the actor. Just remember that at a certain point (I've found it to be 25mm or less) getting very close to the actor will result in some facial feature distortion. For better or for worse.
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Sorry, I wasn't using latitude in the correct terminology, that term is new to me. Dynamic range is what I was writing about in another thread but didn't honestly know the name for, thank you!
I was meaning that I wouldn't have the room to open the iris up if need be, as I'm shooting in the darkened forest. I want to be able to open the lense up if I absolutely have to. On another note, I'm assuming shooting between f/4 and f/5.6 is the sweet spot on the lense, does that mean I've got the best dynamic range as well? My Letus takes off half a stop, so is it really 3.5 and 4.1 I want to be at on my lense?
 
Both approaches, moving closer with the same focal length lens or switching to a longer focal length lens for the CUs, are acceptable, but I would not use different approaches in the same scene. Actually I would not use the different approaches in the same film unless it was decided to differentiate the CUs from one scene to another. Like Ryan said, you can get the same DOF with different focal length lenses, but because of the change in magnification, and the foreshortening of the images with longer lens, they will look different. The differences would be exaggerated if cut together in the same scene and may be jarring to the viewer. I would suggest is picking one way of doing it and using that method for the entire project to maintain visual consistency. Of course, switching it up, if done consciously and for an effect, like giving a character special emphasis in a scene, is always a possibility also.

I am using vintage Nikkor primes on a video DSLR and haven't found that they have a "Sweet spot" at 4.5 or so. I have not specifically test for that, but with the lenses I have, mostly pre-AI Nikkor primes, 24mm F2.8, 35mm F2.8, 50mm F1.4, a 50mm F2 and a 200mm F3.5, I have not seen any real difference in sharpness across the aperture range. I also have a 100mm E series, F2.8 lens and it also doesn't seem to have any noticeable differences across the aperture range. I would test your lenses, with your Letus and see what you find.

Given your situation, shooting in a dense forrest, with a lens adaptor, I would look into the possibility of having a way to get some light in there. Reflectors, mirror or supplemental lighting may be somethings that you may want to consider.
 
...

I wasn't clear earlier... how I was taught, is that dynamic range is the amount an image's exposure can be manipulated. It is very closely related to latitude, because it uses the latent information within an image that is usually the result of a great latitude. For instance, celluloid film and a tremendous latitude. So when you shoot with it, in processing or perhaps telecine, you can push/pull the film to great lengths and still get a decent picture because there is latent information in the shadows and highlights to play with. The dynamic range is the amount one can change an exposure of a picture using the information stored by the latitude of an image. I hope that is better explained. That is how I was taught at film school.

The sweet spot on a lens changes per lens. Some are optimal at their most open aperture. I would test, but with older cinema glass and photography glass, the rule of thumb is generally two-three stops closed down from wide open. The sweet spot of a lens usually helps get rid of minor ghosting and chroma aberrations, while improving sharpness.

Don't worry to much about latitude... that comes with the camera. You simply need to worry about exposure, because if properly exposed you'll capture the latitude your camera is capable anyhow. In fact you could slightly under-expose to protect highlights and play with the dynamic range stretch in post, bringing the shadows back up but leaving the highlights. People do this because video cameras tend to carry more information stored in the shadows, versus the highlights which clip very fast. I'd test though, because noise can be an issue.
 
David G. Smith said:
See. I learned that differently. The way I thought it was is the Dynamic Range of a film/sensor is the ability to expose properly across a scene with a wide luminance range and Latitude is the ability to handle under or over exposure with acceptable images from pushing or pulling.

http://en.wikipedia.org/wiki/Dynamic_range

http://en.wikipedia.org/wiki/Exposure_latitude
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Those links seem to present the exact opposite of my thoughts...yikes! :shocked:
However, I make the argument that we seem to rate latitude in stops when describing a sensors capability in capturing from shadow to highlight... not dynamic range. Is this a common mistake I've been taking part in?

So, I am interested to see if many people, including myself, are misusing terms or if there is some justification why wikipedia seems to state the opposite.

Take a latitude test for example, or how we refer to the range of a sensor in steps of latitude. If a camera manufacturer says there are 12 steps of latitude, this does not mean an image can be over or under exposed that much with an acceptable result pushing or pulling back to proper. It simply means from highlight clipping to shadow detail loss, there are 12 stops of exposure between those values. So is dynamic range simply the sum of the latitude stops? If so, what unit of measurement or term do I use to describe the following observation?:

"I find that the 'X' filmstock or camera sensor can be under-exposed by two stops and pushed back in (processing/DI/post) and get an acceptable image"

... what is the unit of measurement or term for that? Latitude? As an example, "RedMX had two stops of underexposure latitude?" Not sure that this conveys the thought accurately.

This is something I'll definitely have to look into. I apologize in advance for the confusion.
 
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It is confusing. I went back to my primary reference, Lenny Lipton's "Independent Filmmaking" (yeah, I'm that old) and it discusses exposure lattitude in detail. It is the ablity for a film stock to handle under and over exposure, and the ability to take a push or pull. I first did this with the old Tri-X B&W reversal stocks, which were normally rated at 400 ASA. We would rate it at 800 and give it a one stop push. I was beautiful, albeit very grainy, which was what we were going for. I miss that stock.

What I still find confusing is is the term dynamic range. Ol' Lenny doesn't mention it for film, only in regards to audio. The unit of measurments is what ever the units of measurement that is used in densitometry:

http://en.wikipedia.org/wiki/Densitometry

It beats the sh*t out of me how that is measured in the digital world.

EDIT: Shoot Ryan, you got that great AC collection. Go back and check out some articles that introduce a new stock and see how they give the specs. That would be very interesting.
 
Ryan, my understanding of the terms is similar to what was offered in the Wiki article. Dynamic Range to me is the combined number of stops above and below a properly exposed subject. So that if recording a DSC chart, we expose for the center chip, and then count the stops above and below that center chip to get the dynamic range available.

Latitude, I tend to think more of as space above or below what is commonly acceptable (say the stated dynamic range) that can be pull back in post. When we speak of film's great latitude, we are not speaking of it's dynamic range, but rather it's forgiving nature of being "over exposed" and still holding details that we can pull back later.

Again, this is just my understanding of the terms, mostly derived from cinematography discussions online and in print (ASC, books, etc.)
 
David G. Smith said:
It is confusing. I went back to my primary reference, Lenny Lipton's "Independent Filmmaking" (yeah, I'm that old) and it discusses exposure lattitude in detail. It is the ablity for a film stock to handle under and over exposure, and the ability to take a push or pull. I first did this with the old Tri-X B&W reversal stocks, which were normally rated at 400 ASA.
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Uhhh, I shot Tri-X for years, bulk loaded it too. But don't EVER remember it being reversal film.
 
I think you guys are right and I have it backwards... a real brain fart for sure... but still, I see 'dynamic range' described in measurements of latitude, and isn't films 'great latitude' a result from a large dynamic range?

I think you guys are right and I did have it backwards, but I'm still a bit uneasy about how the term latitude is used.

David G. Smith said:
EDIT: Shoot Ryan, you got that great AC collection. Go back and check out some articles that introduce a new stock and see how they give the specs. That would be very interesting.
Click to expand...

haha, I'll do that when I get back to LA!

PerroneFord said:
Uhhh, I shot Tri-X for years, bulk loaded it too. But don't EVER remember it being reversal film.
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Good old 5266 and 7266. Yup.
 
PerroneFord said:
Uhhh, I shot Tri-X for years, bulk loaded it too. But don't EVER remember it being reversal film.
Click to expand...

Super 8mm and 16mm reversal stocks. Actually the 400 ASA film was Kodak 4-X. And I do miss that film. I think the Tri-X was normally rated as a 160 ASA in the reversal MP stocks and is still available I believe.
 
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Ryan Patrick O'Hara said:
I think you guys are right and I have it backwards... a real brain fart for sure... but still, I see 'dynamic range' described in measurements of latitude, and isn't films 'great latitude' a result from a large dynamic range?

.
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Yeah, I am pretty sure that latitude and dynamic range are related, but it may be a chicken or the egg kind of thing.... :grin:

I am sure that it is like everything else in filmmaking... changing anything, changes everything.... ya know.
 
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