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Wonky horizons and spirit levels
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Horizons which are just a bit off get the attention of the horizon police rapidly here; and the usual advice is to
use a hot shoe spirit level — or correct in pp.So I found 3 hot shoe levels here, and tried them on a proper spirit level;
Not very encouraging — two of them were considerably off the mark, the other not so bad — but none was accurate.
So I then tried them on the Olympus E30 — this has an electronic level, both side-to-side and front-to-back.
With the camera level, I got similar results — two of them were way off, the other was a bit offThe particular tripod/head/plate combination has no less than 4 built-in bubble levels — the circular ones.
I could not get all of the bubbles in the centre circle.You might like to try to repeat this; but it looks as if hot shoe levels are none too accurate — more of a guide
than anything else; and for accurate horizons, you need to correct in pp.All levels need to be calibrated-
including the ones in/on your camera,
and the one you’re calibrating against.Some are more accurate than others,
you tend not to get those ones free with magazines.Here’s a selection, if you’d like to have a more accurate one, check the price first…
http://www.mcmaster.com/#bubble-levels/=2253f6
You can level a flat shiny surface, like new worktop material, using a ball bearing-
jack it up in the corners until the ball is not inclined to fall off…Then you can calibrate your bubbles against that,
including the one you’ve got those hotshoe ones sitting on.I did that test ages ago (before I lost one of the levels)
but neither was as bad as those…
I reckon they might be beyond saving, too stacked to one side…If you do find one that’s nearly centered,
and you have an absolutely level surface,
you can simply mark the new centre on your plastic,
and use that mark rather than the printed ones…Would it not be quicker to do this afterwards when processing your image? What does it take, 3 seconds?
What I have yet to discover is if the hot shoes in cameras are always level…I think I read somewhere
that some tend to point downwards as looked from behine, but I’m not sure of this.I think that levelling in pp looks simpler than trying to calibrate such small levels [and yes, I do have one 2 metres long, but it’s in the other country].
Ballyman wrote:
Would it not be quicker to do this afterwards when processing your image? What does it take, 3 seconds?
Yes, you can.
Although if the process is E6, or C41, you might be disappointed.
jb7 wrote:
Ballyman wrote:
Would it not be quicker to do this afterwards when processing your image? What does it take, 3 seconds?
Yes, you can.
Although if the process is E6, or C41, you might be disappointed.
I suppose it would be stating the obvious to keep an eye on it in the viewfinder
rather than having to throw away some of them precious pixels (and maybe a vital
piece of the image) when straightening the image in software or when printing in
the darkroom.And no I don’t get all mine straight. :oops:
Cheers,
John.
jb7 wrote:
Ballyman wrote:
Would it not be quicker to do this afterwards when processing your image? What does it take, 3 seconds?
Yes, you can.
Although if the process is E6, or C41, you might be disappointed.
Us digital people never think of that kind of stuff!!! :lol:
rc53 wrote:
What I have yet to discover is if the hot shoes in cameras are always level…I think I read somewhere
that some tend to point downwards as looked from behine, but I’m not sure of this.I think that levelling in pp looks simpler than trying to calibrate such small levels
Every time you rotate, skew, distort, correct distortion, or push pixels anywhere,
you lose the original capture resolution,
and degrade the image.Often that’s acceptable,
and all lenses exhibit distortion, particularly zooms for small formats.Cameras use accelerometers to find levels-
the first device I had that used them was a Macbook Pro-There is a widget you can download-
http://www.apple.com/downloads/dashboard/calculate_convert/carpenterslevel.htmlSo you can use your computer as a level-
there’s also calibration software, called Seismac, if you’d like to calibrate it-There’s also an iPhone leveling widget-
though I haven’t used it, it is meant to be quite accurate.
I do know of people using it to check levels on their view cameras-Using levels on your camera can save a lot of heartache, if you know how to read them-
I’ve got six levels on one of my cameras, and they don’t all agree-
but they do provide a good indication.Of course, for a lot of subjects, it doesn’t matter-
Or if you prefer, for every subject, it doesn’t matter.Alas, I’m on a PC — no fancy mac stuff for me :)
I agree that rotation etc is destructive; but perhaps necessary, as spirit levels don’t
seem very accurate — and the difficulty — it’s human perception — is that a horizon
that isn’t quite level looks so wrong, and is so obvious. A horizon that’s meant to be
titled is OK, and if it’s clearly curved it’s also OK — it’s the minimal deviation from
what we expect that is the problem.
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