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02/08/2007 12:24:00 PM · #76 |
Originally posted by Gordon:
Isn't the visible horizon usually curved ?
I've been living in the middle of land for too long. I miss the ocean. |
Well, technically, yeah. But it's "level" in the sense of real-world geometry. If you have a really wide lens and a really distant horizon you will see some curvature, yes. It's not a practical concern most of the time.
R.
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02/08/2007 12:28:14 PM · #77 |
Thanks, Bear. I was about to post the same thing. It seems to me that water horizons on the ocean are always level. I mean, if they weren't, the water would be flowing to one side.
In the shot of the horse rider, it seems clear to me he's headed downhill to the right because he's headed into the surf. Beaches tilt. So his being level feels wrong to me.
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02/08/2007 12:34:57 PM · #78 |
Originally posted by Bear_Music:
Originally posted by Gordon:
Isn't the visible horizon usually curved ?
I've been living in the middle of land for too long. I miss the ocean. |
Well, technically, yeah. But it's "level" in the sense of real-world geometry. If you have a really wide lens and a really distant horizon you will see some curvature, yes. It's not a practical concern most of the time.
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You can substitute a "really wide lens" for one with pincushion/barrel distortion though, which I'd guess crops up more often than a shot wide enough to show the curvature of the Earth along the horizon.
As for the whole question of levelling, I use PS Elements 5 which has a handy tool that lets you draw along the horizon and it corrects it for you (or you can hold CTRL and draw a vertical line). Does full PS not have this? (I'm guessing it probably didn't when the tutorial was written...).
I was really annoyed that the free rotate in PSE didn't draw a grid (like the one in Lightroom does) until I discovered this.
splidge
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02/08/2007 12:43:13 PM · #79 |
About the question of losing quality from rotating, I just went through that with my "Good" challenge entry. It had some diagonal lines that looked awful when I just rotated the small amount needed to level the shot.
So I experimented, and found that rotating 10 degrees more than necessary, then resizing, then rotating the right amount back to leave it level gave me much better lines in the final image.
Now, you need to resize the long edge to bigger than 640 because your image is on a steep angle, so the distance across the image along the long edge is less than the distance it'll be when rotated back. After rotating back, the actual image area is what you want to be 640, not the working file, because there will be a large white border all the way around.
I'm sure someone can post a formula. It's going to be something like 640/sin(rotation) or maybe it's cosine. I just played with it a bit to get it right.
Message edited by author 2007-02-08 12:44:09.
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02/08/2007 12:45:17 PM · #80 |
Originally posted by splidge:
Originally posted by Bear_Music:
Originally posted by Gordon:
Isn't the visible horizon usually curved ?
I've been living in the middle of land for too long. I miss the ocean. |
Well, technically, yeah. But it's "level" in the sense of real-world geometry. If you have a really wide lens and a really distant horizon you will see some curvature, yes. It's not a practical concern most of the time.
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You can substitute a "really wide lens" for one with pincushion/barrel distortion though, which I'd guess crops up more often than a shot wide enough to show the curvature of the Earth along the horizon.
As for the whole question of levelling, I use PS Elements 5 which has a handy tool that lets you draw along the horizon and it corrects it for you (or you can hold CTRL and draw a vertical line). Does full PS not have this? (I'm guessing it probably didn't when the tutorial was written...).
I was really annoyed that the free rotate in PSE didn't draw a grid (like the one in Lightroom does) until I discovered this.
splidge |
Sure photoshop has that ruler tool for leveling, and it has had it at least back to PS6. It's the one in the tutorial. It's just that in PS you have an extra step, where you go to image/rotate/arbitrary to make it happen. This is actually preferable for a serious 'shopper, as the "automatic" leveling in Elements is not very precise, in the sense that as soon as you finish drawing the line it does the adjustment, there's no pause for reflection.
But more and more I am using the skew tool for my leveling. Of course, as a rule my horizons are very close to level out of the camera (years of practice) so these adjustments are minor. If the off-level is more than a minor amount, the skew tool makes things look weird, and rotation is usually a good idea.
Skew, of course, is not legal in basic editing, btw...
As to the earth curvature issue, for sure barrel distortion is a contributor to apparent curvature, and anyway it's easily fixed in CS2's lens correction feature. But the 10-22mm Canon EFS lens has virtually none, and if I shoot from atop the Pilgrim Tower at Provincetown I can definitely see the earth's curvature at 10mm... Get up in an airplane, of course, and you can see it easily with the naked eye... Why? Because the higher you get, the further away the horizon is....
R.
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02/08/2007 12:47:30 PM · #81 |
Originally posted by splidge:
As for the whole question of levelling, I use PS Elements 5 which has a handy tool that lets you draw along the horizon and it corrects it for you (or you can hold CTRL and draw a vertical line). Does full PS not have this? (I'm guessing it probably didn't when the tutorial was written...).
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That's basically what the tutorial says.
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02/08/2007 12:47:35 PM · #82 |
Originally posted by levyj413:
About the question of losing quality from rotating, I just went through that with my "Good" challenge entry. It had some diagonal lines that looked awful when I just rotated the small amount needed to level the shot. |
Have you tried "skew" instead? That's one of the reasons I use it.
R.
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02/08/2007 12:50:46 PM · #83 |
Originally posted by stdavidson:
The question: Is the horizon 'correct' on this entry or not? |
If the main focal point buildings are vertical, then it's level in my opinion, which yours is, to me. Tweaking the waterline to make everything all geometrically square and perfect and level, etc takes some of the natural feel out of it and becomes so perfect it feels wrong and appears cold & static.
Just my .02¢ .03¢
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02/08/2007 12:53:10 PM · #84 |
Originally posted by levyj413:
Thanks, Bear. I was about to post the same thing. It seems to me that water horizons on the ocean are always level. I mean, if they weren't, the water would be flowing to one side.
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Got to be careful with that 'always' word ;) Some places the ocean waters aren't always level.
like here off the coast of Scotland at Corryverckan (awesome place to go kayaking - so much fun) or the Cortes Bank off the Californian coast ;)
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02/08/2007 01:03:58 PM · #85 |
Originally posted by Gordon:
Originally posted by splidge:
As for the whole question of levelling, I use PS Elements 5 which has a handy tool that lets you draw along the horizon and it corrects it for you (or you can hold CTRL and draw a vertical line). Does full PS not have this? (I'm guessing it probably didn't when the tutorial was written...).
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That's basically what the tutorial says. |
The tutorial talks about noting the angle of the line you draw with the measuring tool and then going into image->rotate->arbitrary to actually rotate, whereas the PSE tool just does it in one step (the instant you stop drawing the line it rotates the image). As Bear_Music says there are disadvantages to this approach in that you don't get a chance to change your mind without resorting to Undo. But then the tutorial method works in PSE too if you prefer to do it that way.
My intent was merely to point out that PSE5 has a one-step tool to do leveling, and was wondering whether CS2 has the same feature...
splidge
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02/08/2007 01:06:52 PM · #86 |
Originally posted by splidge:
The tutorial talks about noting the angle of the line you draw with the measuring tool and then going into image->rotate->arbitrary to actually rotate, whereas the PSE tool just does it in one step (the instant you stop drawing the line it rotates the image). As Bear_Music says there are disadvantages to this approach in that you don't get a chance to change your mind without resorting to Undo. But then the tutorial method works in PSE too if you prefer to do it that way.
My intent was merely to point out that PSE5 has a one-step tool to do leveling, and was wondering whether CS2 has the same feature...
splidge |
Yup, I'm aware of what the tutorial says ;) Photoshop in general has a lot fewer automated ways to do things than the more consumer-orientated elements. E.g., Photoshop doesn't really have a 'redeye' tool, but it has about 50 different ways of fixing red eye. Suppose you could use auto crop & rotate to sort out the horizon ;)
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02/08/2007 01:07:50 PM · #87 |
Originally posted by Bear_Music:
But more and more I am using the skew tool for my leveling. Of course, as a rule my horizons are very close to level out of the camera (years of practice) so these adjustments are minor. If the off-level is more than a minor amount, the skew tool makes things look weird, and rotation is usually a good idea.
Skew, of course, is not legal in basic editing, btw...
As to the earth curvature issue, for sure barrel distortion is a contributor to apparent curvature, and anyway it's easily fixed in CS2's lens correction feature. [...] |
My understanding is that lens correction is also not legal in basic editing. Is this correct?
splidge
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02/08/2007 01:20:42 PM · #88 |
Originally posted by splidge:
The tutorial talks about noting the angle of the line you draw with the measuring tool and then going into image->rotate->arbitrary to actually rotate... |
Except you don't have to "note" anything: draw the line, go to rotate/arbitrary, and PS has calculated the deviation and entered it in the field for you. It's very fast.
R.
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02/08/2007 01:25:31 PM · #89 |
Originally posted by Bear_Music:
Except you don't have to "note" anything: draw the line, go to rotate/arbitrary, and PS has calculated the deviation and entered it in the field for you. It's very fast.
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Yup, works on vertical and horizontal lines and is easy to use to make arbitary angles correct too (as it works out the declination automatically and you can just add/ subtract to get what you want)
This would all have been much simpler if I hadn't drunk so much Sol in Mexico and shot my horizons squint. That's why I use a bubble level now.
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02/08/2007 02:40:01 PM · #90 |
Originally posted by Bear_Music:
This is why I suggest the skew tool as an alternative to rotation. ... this is an image with no "true" horizon. Strictly speaking there is no "horizon" at all since "horizon" is defined as "the line where earth and sky meet", but for purposes of our discussion you have a "visible" or "implied" horizon where land and water meet at the riverbank, and it is naturally skewed because you are not set at right angles to it.
Your decision is whether it is best to go with the "true" angles or adjust them artificially to something that works better for the eye. If the angle were more pronounced here, that would look perfectly natural: but you have an "in-betweener" where the "correct" rendering is not necessarily the best one, aesthetically. You can use the skew tool either to exaggerate or eliminate the angle. ...
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Thanks. I had not considered 'cheating' to make the image right for the human eye. I'm getting to be more of a purist than I thought in my old age. LOL!!
An important thing to remember in artistic photography is that an image looks 'right' for the human viewer. Sometimes a little adjustment off 'reality' is necessary for that to happen.
I should have considered your approach, or perhaps Gordon's with the perspective tool to 'fix' the image. :)
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02/08/2007 02:43:17 PM · #91 |
Originally posted by stdavidson:
I should have considered your approach, or perhaps Gordon's with the perspective tool to 'fix' the image. :) |
The perspective tool is nice, but you need a lot of croppable area to use it. It would have given you problems in this shot, unless this is a crop from an image that had more sky and river both.
R.
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02/08/2007 02:47:47 PM · #92 |
Originally posted by Bear_Music:
The perspective tool is nice, but you need a lot of croppable area to use it. It would have given you problems in this shot, unless this is a crop from an image that had more sky and river both. |
It did have more image I could possibly have worked with.
Glad I asked the question about this image. Your unexpected response was both correct and enlightening.
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02/08/2007 03:26:47 PM · #93 |
Originally posted by stdavidson:
I should have considered your approach, or perhaps Gordon's with the perspective tool to 'fix' the image. :) |
At least as far as I am aware, it is the same tool. All under the Image-Free Transform. That's what I usually use anyway, bits of perspective, skew, rotate, scale etc all in one.
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02/08/2007 03:27:14 PM · #94 |
Originally posted by Pedro:
... the horizon in this photo will forever be my Nemesis; the ground slopes one way, the clouds seem to slope the other way (the implied horizon), and I sloped at yet another angle (mid-descent on the plane).
There is no correct answer as far as I can tell, so i had to pick a happy medium and move on :)
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I agree there's no one way to align this shot, but I do see choices of seeing here. The sky including the cloud-scape take up a good 2/3 of horizontal space. Everything below the true horizon, really, little more than a minimally gradated base line, however weighted (the black), which makes for a decent natural balance and conventional viewing.
If you straightened the implied horizon, you'd have a perspective shot, more dynamic than any other choice, but also one with a skewed base line, a flaw, if you will. You still have a title though to counter-weigh the flaw... and tilt the viewer. :-) |
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02/08/2007 03:46:42 PM · #95 |
Originally posted by zeuszen:
There is no correct answer as far as I can tell, so i had to pick a happy medium and move on :)
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I agree there's no one way to align this shot, but I do see choices of seeing here. The sky including the cloud-scape take up a good 2/3 of horizontal space. Everything below the true horizon, really, little more than a minimally gradated base line, however weighted (the black), which makes for a decent natural balance and conventional viewing.
If you straightened the implied horizon, you'd have a perspective shot, more dynamic than any other choice, but also one with a skewed base line, a flaw, if you will. You still have a title though to counter-weigh the flaw... and tilt the viewer. :-) [/quote]
I certainly don't see a 'correct' answer either, though the only thing that disturbs my eye is the almost flat, slightly sloping down to the left bottom black section. It almost feels like if you skewed/ stretched that bit so it was even more of a downward slope, it might all balance out a bit more (i.e., pull the orange triangle below the clouds to be more of a isosceles triangle rather than the current scalene shape.
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02/09/2007 12:06:13 AM · #96 |
Originally posted by Gordon:
Originally posted by stdavidson:
I should have considered your approach, or perhaps Gordon's with the perspective tool to 'fix' the image. :) |
At least as far as I am aware, it is the same tool. All under the Image-Free Transform. That's what I usually use anyway, bits of perspective, skew, rotate, scale etc all in one. |
Skew moves the corners independently of each other. Perspective moves them together and symmetrically. The closer a line is to the center of the image, the more radical a perspective adjustment you need to make to affect it. More or less, anyway; to be honest I have rarely used "perspective", preferring as a rule to straighten things up with independent skew adjustments.
R.
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02/09/2007 12:11:39 AM · #97 |
make sure you're wearing 2 shoes.
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02/09/2007 12:17:35 AM · #98 |
In a sense, there is a true horizon that can be derived from Pedro's shot, and it consists of the horizontal line projected off the top of Fujiyama, and echoed by the line barely visible of cloud cover at its foot. Using skew tool on lower left corner levels these up and produces a significantly increased "slope" in the foreground, resulting in perhaps a more dynamic composition.
R.
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02/09/2007 12:48:17 AM · #99 |
Originally posted by Bear_Music:
Skew moves the corners independently of each other. Perspective moves them together and symmetrically. The closer a line is to the center of the image, the more radical a perspective adjustment you need to make to affect it. More or less, anyway; to be honest I have rarely used "perspective", preferring as a rule to straighten things up with independent skew adjustments.
R. |
Yup, I know what the words mean - but they are both the same tool in Photoshop. Edit-Free Transform does both and more all at the same time if you want to. You can use the more constrained versions under the Edit-> Transform menu but I've never seen the point.
Funnily enough, here's what I was trying to describe above about re-balancing Pedro's Fuji shot. Ended up almost identical.
Strip out the border, Ctrl-A to select all, Ctrl-T for free transform, Ctrl+shift left button drag the bottom left corner down.
Ctrl switches it to skew mode, the shift ensures it skews in constrained angles (0,90)
Message edited by author 2007-02-09 00:57:05.
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04/09/2007 11:48:55 PM · #100 |
For Gimp Users:
-Click Measure/Angle tool and drag along horizon just like in tutorial. In status window, it will tell you show you the degree offset.
-Layer->Transform->Arbitrary Rotation (shift R)
-Then in the Angle dialog box, enter the angle offset. Negative for CCW, postive for CW
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