sam_mahmoud
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Posts posted by sam_mahmoud
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Already sick with the cancer that took his life but never could take
his smile. Rest in peace, my friend.<div>
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<p>If the clamp will come off of the ballhead, an easy solution would be to replace the clamp with a clamp that is compatible with Arca-type plates. Kirk and Really Right Stuff sell just the clamp by itself for that purpose.</p>
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<p>This device is nicely made and will do the job. It's made for 3D, but will hold two cameras for other purposes too.<br>
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<p>Maybe your friends don't mean "editing" in the way you're thinking. Editing can mean selecting the good ones and throwing away the bad ones. That is the traditional meaning. If a photographer said "I don't show my pictures until they are edited," that is what I would assume it to mean.</p>
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<p>You can use any normal cable release and add a 90-degree adapter at the end. Here are a couple of examples of the adapter:<br>
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<p>No.</p>
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<p>It's real. Expensive, but real. RBT cameras (and projectors and slide mounts and other hardware) are well known in the 3D community. I have actually spoken to the proprietors of this company (3D concepts) in person years ago at a trade show and they were definitely actual human beings selling real products.</p>
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<p>Years ago, I had a pair custom made by Mekan boots of Salt Lake City. They are heavy-duty (I can't imagine ever wearing them out), beautiful, and of impeccable quality, and there's no question about where they are made. They weren't cheap and they aren't lightweight.</p>
<p>At the time, they mailed me a tray of compressible foam. I stepped in it and mailed it back. Gary Mekan and his staff then custom made my boots to fit the impressions in the foam from my individual pair of feet. They then went even further -- they sent me the half-finished boots for me to try on, giving me a chance to ask for any needed adjustments before they put on the soles and did the final finishing. A classy operation making a really fine product.</p>
<p>I'm not sure if Mekan makes custom boots anymore. They don't seem to have a web site. I did find a picture of one of their boots here:<br>
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<p>The standard underwater photography answer to this is to stay with the slow film, but add a flash.</p>
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<p>Working in increments of 1/3 stop is just fine. Don't change to increments of 1/2 stop just because a spotmetering tutorial happened to be written using 1/2 stop increments. As Rainer and Stephen said, if you choose the nearest step available, you will only be 1/6 of a stop off. You won't see a difference of only 1/6 stop. Plus, of course, the tutorial that said to use minus-one-and-a-half was only giving a rule of thumb in the first place. Your buffalo may be darker or lighter than theirs.</p>
<p>The best spotmetering tutorial I know of comes in book form from Bahman Farzad. Similar information can be found elsewhere, but this is such a basic, direct presentation that it will drum it into your head (maybe at the expense of being boring from the repetition).</p>
<p><a href="http://www.amazon.com/Confused-Photographers-Guide-Camera-Spotmetering/dp/0966081706/ref=sr_1_4?ie=UTF8&s=books&qid=1246297750&sr=8-4">link to book at amazon.com</a><br>
<a href="http://www.spotmetering.com">link to spotmetering.com web site</a></p>
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<p>You can get an adapter that goes into the camera's hot shoe and provides a pc outlet for strobes. It's a generic, inexpensive item.</p>
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<p>If you saw this in the context of studio lighting or flash, it does make sense to only give an aperture, because the shutter speed turns out to be almost irrelevant.<br>
As an example, let's suppose you keep your shutter open for a long time, like 5 seconds. Some time during that 5 seconds, the studio strobes (or your flash) emit a huge bright pulse of light. Let's just arbitrarily say that the pulse of strobe light lasts 1/1000 of a second. You really get all your exposure during that 1/1000 of a second. The rest of the 5 seconds your shutter is open, there's a tiny bit more exposure accumulating from the relatively dim ambient light in the room, but that exposure is so little compared to the exposure during the strobe that it doesn't matter.<br>
As long as you are working under these kinds of conditions, that shutter speed of 5 seconds could have been quite a lot longer or shorter and it would make no difference.<br>
Obviously the shutter speed is not 100% irrelevant, just "irrelevant within reason." It must not be so fast that you don't capture the whole strobe pulse, it must not be so fast that it exceeds your camera's rated flash sync speed, and it must not be so slow that the ambient-light exposure starts to be comparable to your strobe-light exposure.</p>
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<p>Malcolm and JDM are correct that attaching two cameras together is a common problem in 3D stereo photography, and you can get some inspiration by looking to what the stereo people do.<br /> <br /> Stereographers will sometimes even attach their cameras bottom-to-bottom just like you are proposing -- the only difference is that for 3D they would turn the whole rig sideways to keep both cameras in vertical orientation side by side rather than one underneath the other.<br /> <br /> There are a couple of bracket arrangements from Jasper Engineering on these pages:<br /> <a href="http://www.stereoscopy.com/jasper/vertical-parallel.html">http://www.stereoscopy.com/jasper/vertical-parallel.html </a> <br /> <a href="http://www.stereoscopy.com/jasper/vertical-toe-in.html">http://www.stereoscopy.com/jasper/vertical-toe-in.html</a> <br /> <br /> You can also do it with a simple bolt. The tripod socket in the bottom of an SLR is usually a standard size and thread (I've forgotten what size, but it's pretty standard.) A bolt with its head cut off, or small length of threaded rod, will fasten two cameras together. If you try it with just a bolt and no kind of bracket in between the cameras, you will want to be careful of the length of the bolt so that it doesn't bottom out in either camera's socket and potentially damage the socket. You will also want a piece of some squishy material (like a mouse pad?) between the two cameras' bottoms. That's so you can get them tight to each other while not damaging either camera's bottom and still having some wiggle room to tighten or loosen a bit to make the lenses point the same direction.</p>
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You might try Superior Color Lab. It's been
a few years since I've been there, so I'm not
sure if they are still there or if they still
do E6. They don't seem to have a web site.
But they were good when I used them.
<br><br>
Superior Color Lab<br>
1202 Lincoln Ave Ste 106<br>
San Jose, CA 95125 <br>
(408) 287-7884<br>
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The most typical thing to do with this type of stereo
camera is: shoot positive (slide) film. Mount each
pair of slides in a stereo mount. View in a viewer.
(Stereo projection is also possible from such a
mounted pair.)
Mounts are available in several different styles from
several different vendors.
There isn't generally any reason to mount stereo
negatives the way you'd mount stereo slides. You
are unlikely to want to view negatives in a viewer
or project them, which is what mounting is really for.
About the only reason I can think of to mount them
is if it is part of your master plan for storage
and archiving: it would keep them together in pairs,
you could store them with your stereo slides, and
it might give someone in the distant future a clue
that these are stereo pairs. But the point is:
don't mount negatives unless you can articulate a
reason to do so.
So assuming you have negatives you have already
shot, what DO you do with stereo negatives? It
really depends on how you want to present the
images. The final output in stereo can be presented
in a lot of different ways (stereocards, hand
viewers, projection, anaglyph, gallery installations,
lenticulars, "phantograms," side-by-side prints,
over-and-under prints, books with built-in viewing
devices, ViewMaster reels, and on and on). Once you
decide what you're trying to end up with, I think
you'll know how to get there given a negative as
a starting point.
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Thanks, Dennis. Somehow I had genuinely missed that it was a
different player.
I do have a technical theory to offer. I could be remembering
this completely wrong, but I seem to recall that Canon's flash
algorithm has an feature in which, if the ambient light is above
a certain limit, it decides you must want fill-flash for
catchlights, so it reduces the flash exposure. Could it be
that the ambient light was very close to that cutoff and
one exposure kicked in that particular feature and the other
did not?
My other thought was that the exposure algorithm is weighted
for the acctive focus point. Obviously neither exposure is
focused on the trees, but possibly one is focused on the face
and the other on the uniform, which is white?
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If these photos were taken 17 seconds apart, then she must have
been pretty darn busy in those 17 seconds. She painted her nails,
took out an ear stud, and changed the garment she is wearing
underneath her numbered uniform shirt -- all in 17 seconds!
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I like this one. It's a little download. It
gives azimuth (direction) as well as times, and
also gives sunrise, sunset, and twilight times.
<a href="http://www.iserv.net/~bsidell/moonrise.htm">http://www.iserv.net/~bsidell/moonrise.htm</a>
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Hmmm. The stuff from Kapture is awfully expensive.
The LC4 is also pretty expensive and I see nothing on
the spec sheet that promises that it can deliver a
"shoot on breaking the beam" function. By way of
exploring an alternative, I'll just tell you how I
did it, but I certainly don't claim it's any better.
I found an infrared sensor at Radio Shack, the type
that is sold for burglar alarms. The trick is to find
one that has a 'normally open' output as an option.
Most are 'normally closed.' Once you've selected an
infrared sensor, you'll need just two things: a way
to power it and a way to connect its output to the camera.
For power, I used some battery holders, C-type if I
remember right, enough to add up to the right voltage
figuring 1.5 volts per battery. To trigger the camera
from the sensor, you just need a long wire and the right
connector for your camera's wired cable-release socket.
For me this was easy, because I used an Elan IIe
whose socket can be fit with a small audio connector
that is a reasonably standard component.
My setup went like this: Tape the IR sensor to the
outside of a small cardboard box to hold it up vertical
at near ground level. Mount the batteries for the IR
sensor inside the box. Run the output wire from the
IR sensor up to a tripod where the camera sits. Run
another long wire from the camera to a flash on a second
tripod. Set focus, exposure, and flash all to manual
settings based on knowing where the subject will be.
Stick your hand into the area once to test the system,
then leave.
This proved to be a hideously bad implementation of a
remote camera. The finished setup is gangly, with lots
of wires, lots of flaky connectors, and different batteries
everywhere. It was vulnerable to moisture, to theft, and
to being knocked over. The batteries in the flash would
barely last overnight, and the batteries powering the
infrared sensor barely longer than that. The infrared
sensor, when tripped, would hold its output switch closed
for long enough to make the camera shoot 6 or 7 frames,
all of which were completely black except the first one
because the flash would only fire once. This wasted
lots of film and meant that the setup would only get
5 or 6 good images on a roll.
Having said how bad it was, I also have to point out
that it fulfilled my requirements beautifully.
It was cheap, I assembled it in a couple of hours,
and it succeeded in producing well-exposed, well-lit
pictures of wildlife in my back yard, some of which I
didn't know had been visiting my yard. If it's only
a few feet from your door and you're only going to
leave it overnight and don't mind tending it rather
intensively, this is a solution that works. If you
want something you can leave unattended deep in the
woods for months on end, well, let's just say quite
a bit of design refinement would be needed.
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I use a dedicated stereo camera -- not a Realist, but the
same general type -- and I think it is definitely worth
the trouble. I haven't used a "beam splitter" (in quotes
because that is a misnomer; it's not really a beam-splitter
at all) of the type you're looking for, so I can't
make a meaningful recommendation of one over the other.
<br><br>
Examples to show...well, what purpose would it serve?
What you get from a dedicated stereo camera of this type
is two slides on ordinary 35mm film, each 5 perforations
wide (a normal 35mm frame is 8 wide) making them just
slightly taller than they are wide. Other formats exist
if you don't like that size or aspect ratio. Each slide
is tack-sharp, because the fixed 35mm lenses on these
cameras are of excellent quality, and always well exposed
because these cameras don't have any meter and so the
photographer has to use a handheld meter and think. You
mount the two slides yourself in a single mount and
put that in a viewer, or embark on 3D projection.
If I scanned a pair for the web, all you would see would
be two images, just as if I had scanned two slides from
a normal 35mm camera and cropped them to 5/8 of their
original width.
<br><br>
There is loads of information out there. Here are some
places to get started:
<br><br>
<a href="http://home.att.net/~drt-3d/">Dr. T's 3D site</a>
<br><br>
<a href="http://www.stereoscopy.com">Stereoscopy.com</a> which, although I can't get it to load at the moment, usually has all kinds of resources.
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<a href="http://groups.yahoo.com/group/photo-3d/">The Yahoo Groups photo-3d mailing list</a>, where all kinds of experts on
this subject hang out. Someone there will surely steer you
in the right direction.
<br><br>
<a href="http://home.att.net/~osps/tutorial/">Dr. T's Tutorial</a>
<br><br>
<a href="http://www.acsu.buffalo.edu/~kswiatek/StereoIntro.html">Another tutorial</a> with a quick summary of different types of equipment.
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I recommend <a href="http://www.horizon-electronics.com/">Horizon Electronics</a>.
<br><br>
They are a privately-owned shop that is an authorized
warranty repairer for Canon and Nikon and seem to
work only on those two makes. I have been happy with
a number of repairs they have done for me. They
are located in the bay area, which isn't local
to you but at least it's in your time zone and
a pretty quick trip by ground shipping. Most of
their business comes in by parcel rather than
through the front door.
<br><br>
I would send the camera and lens together and
explain EXACTLY what the problem is, then hope
like heck that the problem doesn't disappear
when the technician looks at it.
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I can't give you a direct answer, since I haven't
used this piece of equipment. Two hopefully-useful
things I can say are:
1. The mailing list photo-3d (at yahoogroups.com)
has a vast population of experienced and helpful
stereo/3d practitioners who can help, or at least
offer an array of informed opinions.
2. If your main criterion for a buying decision is
whether or not it's going to be fun...it's very
subjective, but my own opinion would be that this
is definitely going to be fun.
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Others have already said it, but I'll try to say it shorter:
a longer lens farther away will capture the same amount of
light as a shorter lens close up, as long as your framing is
the same and your f-number is the same. The 24/1.8 and
28/1.8 will collect the same amount of light, you'll just
have to move a little farther back with the 28/1.8 and a
little closer with the 24/1.8 to get the same subject in
the frame. An exception would be if the air isn't very clear,
like fog, haze, smoke or underwater photography. In those
cases, you really do need to choose a wide lens and get close.
The easiest solution to your problem is therefore to get
the fasest f-stop lens you can, of any convenient focal
length, that fits your existing system. Don't mess with
adapters and foreign lens mounts.
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It sounds to me like a nice portrait lens.
Adding a 1.4 teleconverter to a 50mm f/1.4 or a
50mm f/1.8 creates a 70mm lens at f/2.0 or f/2.54
respectively. That's still a faster lens than the
70-200/4 you are comparing it against, so it will
blur the background more if used wide open. Just
the thing for portraits. I have actually done this,
but for nature shots, not portraits. I was happy
with the results. These lenses have both sharpness
and speed enough to spare for the teleconverter.
To answer Peter's question, a 50/1.8 with a
2x teleconverter is a 100/3.6 lens in every
way. (well, it may actually be 3.5, but that's
a matter of whether the f/1.8 on your lens
really means exactly 1.8). It has the depth
of field one would expect of any 100/3.6 lens.
If the manufacturer had welded on the telconverter
and then hidden it cosmetically so you couldn't
tell, that would be just a different way to
design a 100/3.6 lens.
You can think of it as narrowing the max aperture
if you like. Actually, it is neither light
loss nor narrowing the aperture. It'a an artifact
of the fact that f-numbers are not the absolute
aperture, they are a ratio of focal length to
aperture. Change the focal length, and the
f-number changes. To take an example, that
f/1.8 printed on your lens is literally the
focal length f, which is 50mm, divided by 1.8,
So the real aperture is 50/1.8, which is
<punching calculator> 27.78mm. Your actual
aperture is 27.78mm wide or an optical equivalent
at this setting. If the telconverter doubles the
focal length, the aperture is still 27.78mm,
but now the focal length is 100mm. That means
the f number is 100mm/27.78, which is f/3.6.
Your f number just got smaller even though the
aperture didn't change its size in absolute mm.
All of these calculations are even true for
a perfect, theoretically ideal teleconverter that
doesn't lose any light. Any real teleconverter
will lose some slight amount of light, so there is
also a reduction of light on top of the apparent
reduction in aperture. It's usually not enough
to worry about.
B&H still a good online seller?
in Nikon
Posted
No, not anymore. They used to be very solid and reputable and I had been ordering from them for nearly 20 years. This month I ordered some items and nothing arrived. B&H claims they shipped the items to a place I haven't lived in several years -- they must have gotten that address from old orders, because I entered my correct current address when I placed the order. I now don't have my stuff or my money. B&H customer service refused to do anything about it -- they told me that they shipped the items and it doesn't matter to whom. I emailed the CEO to ask for help and got back a response saying that not only does he back up his customer service's refusal to fix their mistake, he's even willing to go to the length of lying to the credit card company to dispute the credit card chargeback (he intends to tell them I put in the wrong address when I ordered).
There are a lot better options for honest online merchants these days: Adorama, Amazon, Kenmore Camera. I will be avoiding B&H and would recommend the same to anyone.