[Apologies for not stating my question better; for some reason the title bar is letting me type in only about 60 characters]
Watching the Senate and Congressional committee hearings, you see photojournalists with their cameras, some standing in the back, and some on the floor in the middle of the room. Frequently they are using very long lenses that I, as a hobbyist, would expect to see only if one were photographing sports or wildlife at some distance. In a brightly-lit committee room I’d think that an ordinary 50mm lens mounted on any decent quality camera body would be more than adequate.
Do the photographers I see on TV really need all that glass to get good shots of the witnesses and committee members, or do they just use it out of habit?
(1) From the back of a large conference room a 50mm lens is going to give you a fairly wide overview shot of the proceedings. To get any sort of closeup (without getting in someone’s face) your going to need a medium telephoto or zoom.
(2) Even though you might not need a f2.8 max aperture, “pro” lenses in this range are almost always f2.8. That can end up being e pretty big hunk of glass. There is a substantial difference in design and build quality between the pro lenses and the prosumer lenses, if you living depends on the lens working you’re going to go with the pro lens.
A 50mm lens on a 35mm camera won’t get you very close to a speaker from the back of the room. And the longer lenses don’t give you more light (aperture), but less, as they generally can’t open as wide. So it’s not the light, but the closeness that they are looking for.
And the committee rooms I am familiar with are not “brightly lit” from a camera’s POV, at least not compared with an outdoor sunny day.
Now that I come to think of it, if you do have a large maximum aperture, you can pull in more light at higher f-stops, which means a longer depth of field and less refocusing as you move from one subject to another.
Plus, photographers may prefer to get an upper torso shot of one person - from the back of the room, this is a telephoto shot. F-stop is lens diameter divided by lens focal length, so for a long focal length -say 400mm - f2.8 would be 142mm or almost 6 inches diameter. these are typically zoom lenses to get a variety of shots, and the diameter determines the f-stop at maximum zoom. My 400mm for my Canon m-series is F5.6 at 400mm and still about 4 inches diameter.
A higher number f stop is a smaller aperture. You do get a deeper depth of focus with smaller apertures, but at the expense of needing a longer exposure time. Shooting at f22 in a conference room will probably result in an impossible to hand-hold exposure time of around one to two seconds.
The maximum aperture of the lens has absolutely no bearing on this. An f2.8 lens will not “pull in more light” at f22 compared to an f5.6 lens at f22.
What you can do with a wider aperture is potentially get more hand-held shots. My f1.8 lens will let me shoot at around 1/30 second indoors, quite doable vs that entirely impossible two seconds at f22. One caveat is that wider apertures have narrower depth of field. The DOF at 1.8 is brutally shallow. If I focus on a person’s pupils, the tip of their nose will not be in sharp focus. Conversely, at f22, pretty much everything from my feet to the wall behind them can be razor-sharp.
Also, these lenses might be zoom going from 70mm to 200 or 300mm. In this sense, they are not necessarily very long: 70 mm is perfectly adequate for full body shots in a spacious room.
A 70-200mm 2.8 can be quite large and bulky but it is not seen as a long lens, rather as a polyvalent lens. Professional photographers don’t mind the extra expense (the weight is a bit of a discomfort but one lives with it). And frankly, the superlative optical and build quality (I am thinking about the Canon here) makes it a pleasure to use.
I don’t think people really think about how much MORE light there is in full sunlight than in a “well-lit” room. There’s a reason studio lights are so hot - they have to be much brighter than normal room light. In the days of film, I recall, indoor lighting was barely passable for flash-less photography. Today, low-light photography still produces grainy (noisy) photos with less definition -hence the need for big (wide) lenses. Yes you can stop them down to f22, but in that lighting, you probably wouldn’t.
Indeed, small depth of field and fuzzy backgrounds is often a plus in photography - focus attention on the main subject.
They are using cameras with full-frame sensors. Roughly speaking, the effective “magnification” is proportional to the lens focal length divided by the sensor diameter. Thus to produce, say, 3x “magnification”, takes a physically long lens on a full-frame camera.
By contrast an inexpensive camera with a smaller sensor can deliver greater image magnification with a physically shorter lens, but the quality isn’t as good due to the small sensor’s poorer low light performance. Also the depth of field will be deeper and not provide similar visual isolation of the subject.
It’s possible to add optical tele-converters which increase the effective magnification by, say 1.4x or 2x (and some photojournalists use them), and this only slightly increases the lens length. However these cost either 1 or 2 f-stops, reducing low light performance. Often an interior room that we perceive as “bright” is actually quite dim in term of measured lux. The problem is if they must rapidly remove the tele-converter this takes precious seconds.
When I shoot tight shots on a long lens I generally like to be around f/2.8-f/4, but I will pull out my 85 f/1.4 to shoot at around 1.8-2 when I really want a razor thin depth of field. Generally, for that type of non-environmental portraiture, most photographers do want to limit depth of field for aesthetic reasons, as you say.
I’ve shot a good number of conferences, and I am almost always at least some of the time at 200mm, sometimes with a 1.4 teleconvertor, with my 70-200 f/2.8, and many times wishing I had a 200-400, but that’s not a lens I have in my bag. (I used to shoot a lot with a 400 f/2.8, but that is huge and was provided to me by work. I mean, so is the 200-400, I guess.)
For that type of photography, if you want high quality closeups, a long lens is certainly desirable.
I wouldn’t take a portrait photo of someone using a 50mm lens. If you try to get close enough to have them fill the frame, then you get some of that mouse-face distortion we associate with selfies.
Real portrait lenses live in the 100-200mm range. The one I currently use is 185mm. I use that at any event where I want to get a decent head shot of someone.
Besides providing a more pleasing representation of the person’s face, the background will be blurred at higher f-stop numbers.
With a 50mm lens you need to open it to f/1.8 or f/1.4 (if you can) to get good bokeh. With a 185mm lens, you can get that same background at high f-stop numbers.
As an aside, the “mouse face” look is not caused by distortion or bending of lines, rather it’s caused by how close the lens forces you to stand. A good portrait lens places you 10-15 feet away from the subject, ensuring normal looking features.
With regards to the “why wouldn’t you want wide apertures” question somewhere up-thread, I have to strike a balance between having only one eye in focus (hopefully the near eye) and having all of the mess behind someone in focus.
Even if a lens will allow paper-thin depth of field, I will typically set it at f/4 or maybe a little wider. Super blurry people with one eye in focus aren’t my favorite style.
Besides, you have absolutely no wiggle room with the widest aperture–if you aren’t spot-on, the photo is ruined.
When I am taking school portraits, the kids are not necessarily staying still, so that f/4 (with off-camera flash) ensures I get good crisp images.
And if I am using a nice backdrop of some nature scene, the backdrop blurs unnaturally since everything is physically two feet behind the subject, but the backdrop has distant trees and such that should be more blurry than the closer trees.
Also remember that pro photographer covering newsworthy events (I assume Impeachment Hearings qualify) will want to be sure that when they take a picture, it will be magazine quality, sharp enough that it could be printed full page at 11x8 and still look sharp - as opposed to traditional snapshots that might be printed 4x6, or more likely shown on a screen at 1920x1080 and we’ll tolerate a bit of blurriness.
8x10 at say, 200dots-per-inch (although 300dpi is preferable) is 1600x2000. 300dpi is 2400x3000 - both sizes are far sharper than a typical monitor. While this is only about 7 megapixels you have to also allow for cropping and for the focus then to be razor-sharp. Really good focus is a feature of high quality lenses.
That’s still a good bit slower than you’d want shooting a specific person. If they’re sitting still, or you’re just getting an overall view of the room and everyone in it, then that’s ok, but if they’re talking or gesturing in any way that’s going to be blurry. I’d be wanting 1/200 preferably.
Some times the rules say that you cant be right in front with flashes popping, but mostly i have seen that associated with weddings. As well the mid field togs might be just outside the security perimeter, no not to get into any hassles with the capital police or SS, it may just be less stressful to get out the long lens.
Hobbyist here. I just got a zoom that goes up to 400mm, with image stabilization. It replaces my other zoom that went to 300mm and the difference is significant. I’m very happy with it. And I prefer working with natural light.
The higher power zoom really draws in your subject, allows you to frame more creativity with the broader zoom ranges — especially if your mobility is limited like in these hearings, and with modern image stabilization the pictures are crisper and cleaner than like they were back in the old days of 35mm film and no stabilization on the longer focal lengths.
Sometimes you WANT more than one thing to be in focus. For example, in a Congressional-testimony type situation, you might want to get a picture of the witness and a specific government official listening to the witness–and have both faces in focus.
There’s likely going to be enough physical separation between the two that anything bigger than 4.0 won’t give you enough DOF.