Re: HDR programs

On Thu, 18 Jun 2009 18:27:43 -0700, Savageduck
<savageduck@{REMOVESPAM}me.com> wrote:

On 2009-06-18 17:58:30 -0700, Eric Stevens <eric.stevens@xxxxxxxxx> said:

On Thu, 18 Jun 2009 15:52:42 -0700, Savageduck
<savageduck@{REMOVESPAM}me.com> wrote:

On 2009-06-18 09:48:59 -0700, John Navas <spamfilter1@xxxxxxxxxxxxxx> said:

On Thu, 18 Jun 2009 12:39:30 -0400, Charlie Choc
<charlie.choc@xxxxxxxxxxxxxxxxx> wrote in
<a4rk359n9af2qs95a6s44gd674qpbgbh55@xxxxxxx>:

On Thu, 18 Jun 2009 09:31:05 -0700, John Navas <spamfilter1@xxxxxxxxxxxxxx>
wrote:

On Thu, 18 Jun 2009 12:17:27 -0400, Charlie Choc
<charlie.choc@xxxxxxxxxxxxxxxxx> wrote in

My D200 has exposure bracketing, too, but I haven't figured out how to take 3
multi second exposures in .5 sec. ;-)

A lot of the HDR's I do involve some long exposures ...

Why?

Well, when I'm trying to get detail out of the shadows in a cave,
building, etc.

With a D200 why not high ISO?

and also want to get good depth of field is one reason the exposure is long.

Fair enough, but is that really an issue when shooting buildings or even
a cave?

If
I want to get a silky look on the water in a stream or waterfall is another.

I normally use 1/4 second, only rarely more than 1 second.

Try this:
http://homepage.mac.com/lco/filechute/BridalVeilCreek_DSC1003w.jpg
Exposure Time: 1 / 10
FNumber: 22
Focal Length: 24
Focal Length In 35mm Film: 36
Gamma: 2.2
ISO Speed Ratings: 200

or this:
http://homepage.mac.com/lco/filechute/BridalVeilCreek_DSC1008w.jpg
Exposure Time: 1 / 6
FlashPix Version: 1.0
FNumber: 25
Focal Length: 34
Focal Length In 35mm Film: 51
Gamma: 2.2
ISO Speed Ratings: 200

I'm interested to see that you have specified the gamma. Are these
images intended for screen or print and, if the latter, is this the
gamma you use for printing?



Eric Stevens

No specific reason for including the gamma other than copying it to my post.
I probably should have cut it and included lens + camera info:

Lens Info: 24, 120, 3.5, 5.6
Lens Model: AF-S VR Zoom-Nikkor 24-120mm f/3.5-5.6G IF-ED
Date Time: 2009:06:16 11:19:10
Make: NIKON CORPORATION
Model: NIKON D300

OMG! You didn't actually buy that lens did you? In your first scrapshot
experiment I've not seen lateral CA that bad since ... well, since never.
Every P&S camera I've ever used has had infinitely less CA than that, even
when adding inexpensive adapter-lenses onto them. Even worse, it's not
axially symmetric. Must be a shifted or tilted element in that garbage
glass. What a total waste of money. Don't you at least have or know how to
use a CA correction tool in your editor to try and recover semi-useful
images from that POS glass? With the CA being so asymmetric you'll have to
offset each image from two sides before applying it, then remove the
offset. I can think of no other way to recover useful images from such
garbage optics. Seeing as how the second image doesn't display this glaring
defect as badly that means your lens is barely-acceptable through only part
of its zoom range. Or what I more strongly suspect, the zooming mechanism
isn't built to very close tolerances and it shifts some elements to an
offset angle as they move from one position to another. This will cause
this annoying defect to show up at all focal-lengths depending on what
direction you zoomed last. Or more simply by what angle you happen to be
tilting the lens at the time of each shot.

Oh, wait a minute! This is a VR lens. I bet that's what's causing this
asymmetric CA. Okay. It's just a poorly designed optical image
stabilization system. You're just going to have to learn how to use a
steady hand or turn off VR at all times to make sure this doesn't happen.
Then again, this lens likely suffers from both problems. If it was just OIS
CA then it wouldn't be simple lateral CA, but the OIS would easily compound
that problem. The lens is creating the bad lateral CA, the OIS is
offsetting it and exacerbating it to make it more difficult to correct. No
two images will have the same CA in them. Each and every image from that
lens will have to be painstakingly corrected by hand by reinserting the
offset from two sides, then correcting for the lateral CA. No batch-tool
can ever help correct defects in optics like these.

BTW1: Learn to straighten your boring scrapshots. At least do that much so
they're not worse than they already are. From measuring them the first one
is off by 1.2 degrees and the second one is off by a whopping 3.5 degrees.
I'd tell you a simple way to easily and precisely discern this in any scene
with water in it (pay no attention to the angle of the trees), but ... you
don't pay me enough to give you important lessons that you can actually
use.

BTW2: Do you really waste that much shooting and editing time on scenes as
commonplace as these? Another, "Wow". You were shooting these just as an
HDR experiment, learning how, right? You could at least have composed them
better, or something. I guess it's like everyone says, the most important
equipment is the mind behind the camera. Yours is sorely busted. See if you
can sell it on Ebay and get a new one. Just don't let anyone know how
poorly yours performs or you'll get no bidders. Be sure to include the
"make any offer" and "no reserve" options on your ad too, Leonard.

It surprises me what poor quality optics that DSLR owners will tolerate and
try to use. After all, they spent so much on them they must be good, right?
You got what you paid for! Right?!? $600 worth of asymmetric chromatic
aberrations on an $1800 body. Worth every penny! RIGHT?!? :-)


Yes. Sad but true. Only idiots buy and try to use DSLRs. Just one more
glaring example from thousands, as perfect proof.

.

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