Roving Thoughts archives

More on why the Moretsu Pirates zero-G problems annoy me

In response to my entry on zero-G in Pirates, Author noted that problems with zero-G are pervasive and pointed to an example in Rocket Girls (and noted that he's learned not to be bothered by it).

For me, Pirates is different from something like Rocket Girls in two ways. First and most important is that the zero-G mistakes in Pirates are so obvious that I've actually noticed them. I am not an alert watcher for technical details; I'm generally happy to get carried away without worrying about the small things (and the zero-G issues in Pirates are a small thing). It takes a fair amount to make me go 'wait, what?' while I'm actually watching the show. Zero-G in Pirates managed.

(I never noticed the zero-G issues in Rocket Girls, for example.)

Second, using zero-G is an actual setting choice in Pirates. Something like Rocket Girls intrinsically requires zero-G; you cannot have a modern era show in space with helpful artificial gravity. But artificial gravity is a common cliche in future space settings and Pirates could have used it without anyone blinking. When an anime does something through choice instead of need I generally hold it to a higher standard.

(For example, if an anime includes a generic camera I will ignore unrealities about it that would irritate me if the anime is clearly trying to show a specific camera but getting it wrong. You could phrase this as 'if you're going to put in details, get them right'.)

PS: note that Author is in fact more technically correct about the situation than I am. He's using the correct technical term 'microgravity', where I've gone for the slightly inaccurate pop culture label 'zero-G'.

My issue with the zero-G sequences in Moretsu Pirates

Pirates has made the unusual decision to not use artificial gravity in the sole spaceship that we've seen; instead all of the areas of the ship we've seen so far have been in zero G. (It's possible that part of the living quarters have gravity from spin, but the bridge and main ship areas don't.)

Unfortunately there is one bit of how Pirates is handling the zero G sequences that gets to me. It's not how everyone's skirts are apparently nailed down (yes, the schoolgirls are still wearing their uniform skirts in zero G); as noted, this is not that sort of show, and I'm perfectly willing to accept that.

What gets to me is how people maneuver in zero G. Pirates has repeatedly had people floating still in the air, not in contact with anything, and then had them just start moving again without pushing off anything or otherwise having some source of thrust. Sometimes people have stopped in midair (not coasted to a stop, just stopped). It's as if Pirates is treating people in zero G just like people walking along the ground, except they can coast and float and move in any direction.

(Unfortunately this isn't the kind of thing that can be illustrated without an animation clip of some sort.)

Pirates doesn't do this all of the time; a lot of the time people do push off things and stop themselves on things. But not always, and the exceptions make me twitch. I wish that Pirates would either commit wholesale to real zero G or just give up and give the ship artificial gravity.

(Perhaps the clearest example of this happens during parts of the spacewalk in the third episode. I'd try to handwave that as their suit backpacks having some sort of maneuvering thrusters if it wasn't for all of the other times this happens.)

How long an exposure can my camera meter?

A friend and I were talking about long exposure photography today, which brought up the issue of determining how long an exposure you needed. Like most DSLRs, my Nikon D90 will only automatically expose out to 30 seconds; if you need a longer exposure than that, you have to time it by hand in Bulb mode.

(In my opinion this is a pointless limitation, probably reflexively carried forward from the days when there was only so much space on a physical shutter speed dial. Since cameras are computers these days, you could even limit automatic exposures to no more than 30 seconds while still letting the camera count the time for longer manual exposures.)

But that's just how long an automatic exposure the camera will do, not the limit of what it will meter for you. If the exposure is at the 30 second limit and the viewfinder is still reading 1 EV of underexposure, you can fix that with an exposure that has 1 EV more time, ie a 60 second bulb exposure. So how long an exposure can I actually meter with my camera?

• in my normal settings, the viewfinder will show up to 2 EV of underexposure. If I change the camera to use 1/2 EV steps for exposure compensation instead of 1/3 EV steps, this increases to 3 EV of underexposure.

• I can extend the range of the viewfinder meter by adding negative exposure compensation (a 1 EV underexposure with -1 EV of exposure compensation will read as a correct 0 EV exposure). My camera allows up to +/-5 EV of exposure compensation, pushing metering to an effective 8 EV of underexposure.

  (The allowed range of exposure compensation doesn't changed based on the step size used.)

Since every EV is a doubling of the exposure time, 8 EV of exposure past 30 seconds is 128 minutes; call it a two hour exposure. If this isn't enough, I can start pulling the viewfinder meter back by metering with a high ISO but actually photographing with a low ISO. My camera has a base ISO of 200 and is easily raised to ISO 3200, giving me another 4 EV of metering range (a total of 12 EV); that takes me to an exposure duration of over 30 hours.

So the real answer here is that my camera battery is going to die long before I get to an exposure that I can't meter. (Probably the sensor would overheat from continuous use, too.)

(In theory the D90's meter is only specified to work down to -1 LV. In practice this isn't even moonlight and I've metered without problems in much darker conditions.)

PS: since I'm unlikely to sit still for a one hour exposure, much less a two hour one, I don't even need to change the exposure compensation step size. My normal settings still give me 7 EV of exposure past 30 seconds, which is already just over an hour. Mind you, using 1/2 EV steps makes the eventual time calculations somewhat easier.