When Spock enters the bridge, and it cuts to Admiral Kirk, the entire left side of the frame is completely blurred, save Kirk. Is there any explanation for that? Was it to cover something up, or intentional?
It's a split-diopter shot, an effect Wise used repeatedly in the film to approximate deep focus (it also shows up in other films he directed, including The Andromeda Strain). Basically, it allows the two halves of the frame to have different planes of focus. Frankly, I find it distracting and far overused in TMP, but others may disagree. The blurry background behind Kirk eradicates any illusion of deep focus (which means that everything in the frame is in focus, an effect most famously used by cinematographer Gregg Toland in Citizen Kane and The Best Years of Our Lives).
What did they do in later movies then to avoid a too shallow depth-of-field? Light it more to get a high f-stop? Use more wide-angle lenses? Different film stock with higher ASA?
I thought the reason for the tight focus in the bridge scenes had something to do with the dim lighting that was required so the film-reel "monitor" images would be visible. I'm not sure how lighting and focus are related, but that's what I seem to remember reading.
Less light means you need a wider lens aperture which means you have a shallow depth of field. Generally that's fine because the shallow depth of field look is what makes movies look cinematic. They even use filters to take away light so they can use large apertures to achieve that look. But in a dim place you obviously run into issues when you need lots of depth of field. That's often avoided by using wide angles lenses because depth of field is also related to focal length. Or you know... adding more light or a more light sensitive film. Anyway, you probably didn't wanna know all this. I'm just glad I learned something about photography while modeling.
That would be a question for somebody with more technical knowledge than I have. I do know that the production switched from projected film loops (in TMP) to CRT displays (beginning in TWOK). Would that have played into the sequels?
The later films use really different lenses, and the bridge looks much smaller in many shots as a result. I'd have to look up the tech specs of each film to really comment on the why of each look, but as { Emilia } correctly says, the DOF is related to the lens, aperture, shutter speed, ISO (film speed) and light levels. For instance, the DOF is frequently the giveaway on miniature shots, so when filming models you tend to really pump the light levels waaaaaay up to compensate. There's even a formula for it.
The whole thing that makes the diopter approach work is having the delineation on a line in the set and having hard light ... the relatively mushy look of TMP's softlight doesn't make it work nearly as well as say, Wise's HINDENBERG, where you can see it used inside the superstructure in scenes with Atherton and Scott. Also not overusing it helps, but that is something TMP is seriously guilty of. The low-lighting is partly stylistic, partly driven by the projectors not putting out enough light (the monitors in the sequels did a much better job, obviously.) The idea of using soft sidelight in what the DP called a contrasty way is basically a ticket to making sure faces look bad (I always go to the way Kirk looks when McCoy is telling him to back off, pre-wormhole), but if we start talking TMP aesthetics we'll be here till the 23rd century, and beyond. I'm pretty sure TWOK was shot using (at the time) highspeed AGFA stock. I think the rest were all Kodak. Using more light on the sets, especially focused lights, creates pleasant-to-the-eye dramatic contrast (think of McCoy silhouetted on the bridge after everything shorts out in SFS.) The detail I remember from AMERICAN CINEMATOGRAPHER about TMP was that most of the bridge scenes were shot at 20 foot-candles, which is just crazy small amount of light, downright insane given they shot anamorphic (which exacerbates the issue.) If you used this approach today and shot digital, there would probably be no issue at all, as Alexa can see in the dark. Unfortunately that is why movies are starting to look like home videos, because less light is being applied artistically (to tell the truth, the best way to deal with Alexa is, I think, to use negative fill, reflecting black into the shadow areas to increase contrast, and yeah, I'm getting way too technical now, sorry.)
It is a weird concept, one I first heard used for lighting the ship miniatures in ALIEN REZ. You use black foamcore -- not white -- to bounce light off of. When you do it real-world, you're essentially subtracting on the fill side, creating more contrast from what is naturally falling on the key and fill sides. It is used a lot when TV shows are working on location interiors and shooting digital, since otherwise you're just seeing too much detail on all sides. You're basically capturing the location as-is a lot of the time without doing conventional movie lighting at all, but sculpting or molding it slightly ... the difference is that instead of molding it by adding a rim light or some punch to the eyes, you're taking away.
The "taking away" part doesn't make sense since as described you're still reflecting light, you're just doing it off a surface with a much lower albedo. One can't project dark any more than you can generate cold, since both are actually subtractive processes (block light and dissipate heat).
I understood it this way: let's say there's a white wall bouncing off light you don't want. So you put a black board between the actor and the wall, so he doesn't receive any of the bouncing light. So you are "taking away", even though it's not a physically correct term.
Actually, a wider angle lens does not inherently have a deeper depth of field. If I take a photo with a 50mm lens at f1.4 and then take a photo of the same subject with the same aperture but a focal length of 10mm, I can then crop both pictures to have the same framing, and the amount of blurring in each will be the same. The reason the wider angle lens appears to have a deeper depth of field is because any blurring is proportionately smaller in the frame and thus harder to notice. It's the same reason that an out of focus picture still looks sharp on the back of your camera. Make it smaller and it looks sharper. SOURCE: A decade of experience as a photographer.
Like Jarod says you obviously don't want to crop it. 50mm 1.4 Subject distance 10 ft Depth of field Near limit 9.69 ft Far limit 10.3 ft Total 0.65 ft In front of subject 0.31 ft (48%) Behind subject 0.33 ft (52%) Hyperfocal distance 305.4 ft Circle of confusion 0.019 mm compared to 10mm 1.4 Subject distance 10 ft Depth of field Near limit 5.51 ft Far limit 54.4 ft Total 48.9 ft In front of subject 4.5 ft (9%) Behind subject 44.4 ft (91%) Hyperfocal distance 12.2 ft Circle of confusion 0.019 mm Source: A simple depth-of-field calculator. Obviously there's other things that matter. Distance to subject being the elephant in the room when it comes to bokeh and focal length.
Remember too that Wise also locked down many of the sets, and especially the bridge set, and filmed those scenes without removing any of the side walls to accommodate camera, lights and crew. I'm sure he wanted to have the sets seem more claustrophobic that way, and tried the dim lighting to accent shadows, but it wasn't easy given the overwhelming greyness of the color palette... Mark
No. Blocking light is to flag it. Trevanian specifically says the light is bounced off a black surface.
To the OP: That always bothered me. I vaguely remember the process was touched on in the DVD extras of the director's cut, but my memory has been known to be wonky. Regardless, it makes no sense to me to have part of the background more blurry than the rest when there is no major difference in distance between the most of the background and the camera. I know it was applied on purpose, but if I didn't know better I would think someone was trying to blur something out of the scene for legal reasons! LOL! And it happened throughout the film, so obviously it was not a mistake. Here, the background near Uhura is closer to the screen than the viewscreen, yet the viewscreen is not nearly as blurry: Sometimes the blur is so intense, I find myself oddly focused on what is blurry instead of what is in focus. In this case, it's a chair and some boobies (and the boobies are closer to the camera than the background on the left which is a lot less blurry. The chair is just as close as the people in the background, yet there is a drastic difference in the blurriness. Makes no sense.): But the award for strangest use of blur is this one. Take a look at the gentleman standing in the background. The bottom half of his body is more blurry than the top part of his body. I wonder if there is some in-universe technobabble explanation for all of this?