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Messages - TrumpetPower!

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31
Technical Support / Re: Grey card and spot metering
« on: April 23, 2013, 10:00:27 AM »
We appear to be addressing two different issues.
 
The OP is trying to get a correct exposure, while others are talking color correction in post.
 
I think we might be confusing the OP's question of how to get a correct exposure so that extreme measures are not required in a attempt to save a image.

I believe I addressed all that in my first post, the first response on the thread: the histogram shows the whole image, not just the metered part; using a gray card can be tricky due to gloss but works with practice and experience; and a hand-held meter is much superior to a gray card.

But in the ensuing discussion, I've also made note that I use my ICC-based workflow first to determine the proper exposure and then to correct color. Make no mistrake: the first (and, I'd suggest, by far the most important) part of my ICC-based workflow is determining proper exposure settings on the camera and then the proper exposure adjustment settings in development -- and that's precisely the topic under discussion (even if what I do is a bit overboard for what Simon is trying to accomplish).

Cheers,

b&

32
Technical Support / Re: Grey card and spot metering
« on: April 22, 2013, 10:08:33 PM »
I use the X-Rite Colour Checker Passport, you can find info/videos here.

The Passport is a very good portable target and what I use out in the field. The software that ships with it leaves a great deal to be desired, even if it's significantly better than using a gray card or any of the other popular tools.

A big part of the problem is DNG profiles, which really leave a lot to be desired, on so many levels. But it's what you're stuck with if you're processing with Adobe products...and it, in turn, is so much superior to Canon's Picture Styles that it's not even funny....

In the studio, I use my own target that includes a replica of a ColorChecker and a couple dozen other paints and a dozen wood chips and a few hundred patches printed on an iPF8100 and a light trap and some Teflon and probably some other bits and pieces I'm forgetting at the moment....

Cheers,

b&

33
It can be concealed in my hand (barely) when I'm in a shot.

Isn't that what the 3-second delay is for? Press button, slip remote into pocket / turn palm / whatever....

b&

34
If everybody arguing past each other on this thread had started by reading that link, one might imagine a lot less sound and fury....

A vain hope, I'm afraid...   ::)

That, and think of what it would do to the popcorn sales....

b&

35
Lenses / Re: TS-E 17mm or 24mm
« on: April 22, 2013, 08:51:52 PM »
By tilting, you can achieve a deep DOF from front to back and by shifting, you can overcome the keystone effect/converging verticals.

It's not just squared-off manmade structures that benefit from movements, of course, though that's where it's the most instantly obvious.

This attached shot was also made with both tilt and shift on the TS-E 24. The flowers were just a foot or two away from the camera. The Superstition Mountains in the background are a mile or so away...and yet the flowers, the cliffs from base to peak, and the meadow between are all in sharp focus.

This is very close to straight out of the camera, too. No cropping. It's a colorimetric rendition, or very close; I had to dial back the sky by about a stop to bring back some of the color, but that's it.

I haven't made a print of this yet, but I've got plans for at least a 24" x 36" print, or I might even go all the way to 36" x 54.

Cheers,

b&

36
I'm not into the intervalometer thing. When I'm in the field, I'll use the generic Canon wired remote, whatever model number it is. When I'm in the studio, I'll shoot tethered and the spacebar or mouse becomes the shutter release. If I was going to do the intervalometer thing, I'd probably either shoot tethered and let the laptop handle the triggering, or I'd finally spend the time to figure out one of those apps that lets you control your DSLR with your iPhone.

Cheers,

b&

37
http://www.josephjamesphotography.com/equivalence/

If everybody arguing past each other on this thread had started by reading that link, one might imagine a lot less sound and fury....

b&

38
Lenses / Re: TS-E 17mm or 24mm
« on: April 22, 2013, 06:32:44 PM »
For somebody who uses 16mm as often as you do get the 17TS-E. If you want a bit more flexibility with minimal loss in IQ then get a 1.4TC MkIII.

+1

You've done a superlative job working around the limitations of the 16-35, but there isn't a shot amongst those you posted that I personally wouldn't have gone with the TS-E 17 if I had a choice between the two. Now that I've seen what you're drawn to, it seems pretty clear that the 17 is for you, in spades.

Cheers,

b&

39
show me example of the Nikons inferior AWB
the AWB is easy to correct/change  in-house if the results not are as you like.

See that little red “1” at the bottom of the page? Click on it.

Or google "Nikon green cast."

Cheers,

b&

40
please explain what do you mean with this:

But it's not reasonable to expect those algorithms to differ by more than a minor amount, and Nikon cameras are notorious for royally screwing up white balance in exactly the way the original poster has discovered. I'd go so far as to suggest that the cameras are unacceptable as shipped, though the problems should vanish in an ICC managed workflow.

It's a pretty straightforward statement. Even though they use different algorithms, they should come up with relatively close results. In this case, the camera may be defective, but using the process he suggested at but didn't explain in detail, it wouldn't matter.

Egg sack lily.

The cameras should produce onboard JPEGs close enough that you're not going to tell the one from the other just by the white balance, even if they're not exactly the same (and you wouldn't expect them to be exactly the same). But if you're doing color critical work and using an ICC-managed workflow, all that matters is the actual raw data and the camera's wild-assed guesses about proper white balance don't even enter into the equation.

Still, there's no excuse for a white balance system as screwed up as Nikon's. Few people even know that it's something that can be worked around, let alone have the patience to work around it. And you shouldn't have to work around it. It's hardly rocket surgery; it should just work.

Cheers,

b&

41
Technical Support / Re: Grey card and spot metering
« on: April 22, 2013, 05:35:11 PM »
How do you install a ICC profile in your camera to get a correct exposure?

Sadly, of course, you don't....

Quote
ICC profiles are more about getting colors correct.

But exposure is the most fundamental part of getting colors correct! And, in a fully-ICC-managed workflow, the profile is going to correct any exposure errors at the same time it gets the colors in line. A hybrid workflow will at least correct exposure and white balance, which is all you can realistically do outside the studio, leaving it up to your supply of carefully-constructed generic profiles (one in daylight, one in shade, one in tungsten, etc.) to get you "close enough."

Obviously, you need to shoot a target in the same conditions at the same settings as the "real" shot. If you're shooting tethered in the studio, you can quickly build a profile on the fly and analyze it to tell you the exact exposure adjustments and white balance settings you need, and you can then decide if you want to make your exposure adjustments with the camera / lights or (if there're reflective or illuminated highlights that'll get clipped) in post-production. When I'm doing art reproduction, I do so and adjust the lighting to within 1/100 of a stop of perfect exposure in camera.

The same process also (of course) tells you how to adjust exposure and white balance in post-processing, at which point all you're left with is applying the ICC profile.

I use a similar workflow in the field when I'm doing landscape work, except that I generally don't shoot tethered and thus I'll bracket (usually with the auto-HDR because it's so convenient) and pick the best / least-worst exposure as the starting point, and then use the profile of the image of the chart to determine post-processing adjustment of exposure and white balance. Works awesome. Even if you significantly miss the exposure, you've got so much latitude with modern cameras that, so long as you didn't clip the highlights, you can perfectly salvage all but the worst mistrakes...so long as you got that shot of the target (I use a ColorChecker Passport in the field) in the light with the same settings.

Cheers,

b&

42
Lenses / Re: TS-E 17mm or 24mm
« on: April 22, 2013, 04:45:41 PM »
For example:


This is the textbook example of what the TS-E 17 is designed for: close-up photos of tall buildings.

Of course, that's not all it can do, and it's not all it can do really, really, well. But it's basically its primary purpose.

If you're thinking of doing this sort of thing -- or of similar sorts of close-up shots of very big things (including mountains and trees) where you don't want any geometric distortion -- then this is the lens for you. If you have other types of photography in mind, this probably isn't the lens for you.

Cheers,

b&

43
Lenses / Re: TS-E 17mm or 24mm
« on: April 22, 2013, 03:42:27 PM »
I was in a similar position, and I've rented both the 17 mm and 24 mm  TS-E lenses.

If you're not sure which to get, then this is the right answer: rent both.

I love the 24. Whenever I can think of an excuse to use it instead of some other lens, I do. And it takes the 1.4x TC just brilliantly, giving you an awesome 35(ish) lens as well.

I'm personally not drawn to the 17mm perspective anywhere near as much as I am to the 24mm perspective. And when I do want something as staggeringly wide as the 17 would give, I'm generally not going to be satisfied with a mere 17mm lens and I'm instead reaching for the 8-15. But that's just me.

Oh, it, of course, depends a great deal which format you're shooting with. I shoot 135 ("full frame") exclusively. If I shot APS-C ("crop"), I'd be all over the 17 instead of the 24.

Also worth considering is the third-party alternatives. I don't really remember who's selling what, but I do know that somebody's got something new for a fair bit less that still has the independent movements of the Version II lenses. I also understand that the image quality from said lens is supposed to be quite respectable, even if it's not quite as good as the Canon. In other words, it's probably a much better price:performance ratio still with very good performance.

Cheers,

b&

44
Right, the FF lens "gathers" twice as much light, and then spreads the "gathered" light over a much larger sensor. The crop lens "gathers" less light, but then focuses the light onto a small sensor, creating a brighter exposure than the full frame lens despite having "gathered" less actual light.

...but only when shot at an f/number sufficiently smaller such that the actual physical aperture is the same.

In other words, the APS-C camera shot with a 50mm lens at f/1.8 gathers the same amount of light as a 135 camera with an 80mm lens at f/2.8, and framing and depth of field and the rest are also comparable.

50 / 1.8 = 27.8
80 / 2.8 = 28.6

Cheers,

b&

45
Technical Support / Re: Grey card and spot metering
« on: April 22, 2013, 01:07:46 PM »

As noted, be sure to cover the entire frame with your gray card.  If you are using one of the tiny ones, they are generally best for color correction.
Be sure to check things out before actually using it, as Thom notes, camera manufacturers do not use 18% reflectance to calibrate your camera, so your exposure might be off.
http://www.bythom.com/graycards.htm

Thom's points are all correct and useful...but also somewhat dated. These days, if you're looking for perfect
exposure, there are much better methods than a gray card or even a handheld light meter. Specifically, you'll be wanting to get your hands quite dirty with ICC profiles....

But, of course, Thom's suggestions are an excellent starting point, as they're plenty "good enough" for the overwhelming majority of photographers. Unless you have problems doing as he says, there's no point in worrying even about the exact reflectance of your gray card.

Cheers,

b&

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