dSLR thread

Tannin

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As I understand if from ultra-quick skimming the blog pages above, you take your RAW images, then can convert to HD Photo, with this plug-in? So you edit in PS in this file format, after you've acted/edited directly on the RAW images with Adobe Lightroom, or Apple's Aperature...I'm confused? Does this mean a Fuji S5 Pro could in theory get even greater dynamic range from the processed images (not that the Fuji's sensor changes anything, just that you retain more info in final output with HD Photo, yes/no?).

No.

Dynamic range is limited by the output device. Ordinary old JPG can cover the entire gamut from pure black to pure white, indeed, you can use any file format and do that, even a 1-bit per pixel format.

HD Photo looks very much like a solution in search of a problem to me. Look at it this way, there are three things you might want from a photograph:
  • 1: a true representation of all the data captured by the image sensor. Use raw. Or DNG. No other format can achieve what raw (and DNG) achieve.
  • 2: an open, transportable, lossless format with 100% accuracy for intermediate storage of images pending final post-processing and output (printing, resizing for screen display, and so on). TIFF is the answer. Everything understands it, it doesn't suffer from generation loss, and you don't really care about file size because you only use this for a small number of "keeper" images.
  • 3: a universal, small, efficient format for relatively low-resolution end-use images, ready to be printed or displayed on a screen. JPG is the answer. Small, efficient, and every computer on the planet understands it.

So what problen is HD Photo the solution to?
 

Stereodude

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flickr's great, but the user agreement states that you cannot use flickr to host pics shown elsewhere on the net, like discussion fora, banners, etc, but must link directly to the appropriate flickr page. I know a lot of people who just ignore it, though.
That's not what it says.

It says the picture must link back to flickr. Meaning your pictures have to be hyperlinks back to flickr.

Remember! Flickr Community Guidelines specify that if you post a Flickr photo on an external website, the photo must link back to its photo page. (So, use Option 1.)

They even give you the HTML code, but the problem is no forums allow you to use HTML code, so you can't link it back. I've pretty much just ignored it myself.
 

e_dawg

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Indeed, the camera is usually the bottleneck assuming you have a high-speed card. I think most of them are PIO mode 4 or 5 and limited to around 6-8 MB/s (40-50x). The new Nikons have UDMA controllers, though.
 

e_dawg

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Udaman is spot on. I don't like any of the picture-sharing sites. Sorry to be harsh here, but they are all crap. Different strokes and all that, but the way I see it the only way to host pictures is to run your own site.

But how can you have a balanced perspective if you've only really ever hosted your own pics? There are much better services available now. A very small minority actually want to put in all that time and effort to run their own site, and an even smaller number actually know how to do it.

The key points from Udaman's post follow:
  • if it gets automatically scaled, then it won't be in the pixel dimensions you specifically cropped your image for
  • "Optimally sharpened"? In who's eyes? I'd rather do my own sharpening
  • On what basis are you determining 'image quality' for comparison purposes of various sites, which do the least screwing around with your image?

They cover it pretty well, I think.

I think I have adequately addressed all of these concerns in an earlier post. They are a non-issue with something like Picasa and pbase. It's somewhat natural to instinctively be afraid of a service butchering your images, but most of those fears are unfounded.
 

udaman

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People who use Windows mostly say nice stuff about them. This is largely because people who use Windows , in the main, are incredibly ignorant about computing (ie. the masses of consumers, not creative professionals who need to get work done, get *paid* for a living). We know this because we know that they voluntarily and of their own free will use Windows.

AOL users, on the other hand, at least have the decency to feel slightly embarrassed about themselves, which indicates that they are, at least on average, slightly less intelligent than Windows users, if that's possible. But then, so is the green stuff at the back of Tannin's fridge.

Couldn't agree with your more Tea, lol ;)

Let me know when you win an Academy Award for Editing. Walter Murch, he's even written an editing book- the ignoramous! After using a Windblows/Avid Editing system that cost much less than was the normal for the Academy Award winning "The English Patient", Murch ever the trail blazer, looked to an even greater cost effective system that came in on budget @$100k, including the FC fiber optic network they used in Bulgaria (oops, I think it was Hungary), that being 4 Apple G4 1Ghz towers as his editing suite for the Academy Award winning 'Cold Mountain'. A favorite speaker at the local Los Angeles Final Cut Pro User Group meetings, he explained how pleasantly surprised he was at how easy and efficiently the Apple OSX system and FCP software suite worked for him (that was way back when FCP was still at version 3.0- before the huge amount of other formerly very costly software packages bought out by Apple, that now come integrated in FCStudio at greatly reduced cost, that now allow low budget independent movie makers the more equal chance to make better movies than the usual crap that comes out of corporate Hollywood- was available). Pretty much a legendary editor in the movie industry Tea, don't suppose you've heard of him? People use what they are familar with (Windblows) not because it's superior, but because they don't know any better (ignorant). Pioneer cost-cutting professional movie editor Walter Murch knows better.

Tea is probably too young to remember the days when Nikon ruled supreme in the 35mm pro camera market. Then something happened, upstart Canon surpassed Nikon with a great range of lens the pros eventually flocked to. Same will happen with Apple's professional market, the creative people who get *paid* the money to get stuff done! Only in CGI, where Linux based workstations have the lead, is Apple trailing, but hot on their heals too with recent acquisitions of big name software companies that consumers haven't a clue about...pros know. people that Tea is ignorant about. Why is everyone keep linking to the same Galbraith that I did in my prior post, don't they read??? (oh, I see, everyone has me on ignore....hehe).

Expresscard 34 or 54 readers will get the data off your memory card fastest as card readers go, limited only to the current chipset (think it's an Intel choice) in your computer, not the SATA standard- it's faster than FW800, and faster still than USB 2.0. For the thousands they charge, you'd think they could put an SATA port on one of these big, bulky dSLR's with such high MP sensors, how much extra would it cost? If you're not in a hurry, USB 2.0 cable directly connected, is fast enough to transfer small numbers of RAW images from camera to computer.

Constantly removing memory cards from the camera just because you need the highest speed transfers seems dumb to me, the more times you plug something in and out the more it gets to the point of wear problems with the interface...something sexual in that I think ;). Just put a decent speed port on the camera so you don't have to remove the mem. card.
 

ddrueding

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I've been just connecting the camera when I get home. It is programmed to automatically sync the pictures to a datestamped folder, so by the time I return from the kitchen it is well on it's way. By the time I finish cheking in here it's done. I'm just worried about the USB2 port on the camera, with me plugging it in about 2 times a day.

I've now taken to the habit of leaving the camera in 5fps mode all the time, snapping 2-3 shots of every subject. One is almost always better than the rest, with my shaky hands.
 

e_dawg

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Now you'll have a use for all that storage space -- 5 fps multi-shot bursts at a time, several shooting escapades in RAW mode a day... that's a lot of bits & bytes ;)
 

Tannin

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Compact Flash cards and Compact Flach card slots are robust and designed for many, many insertions.

Those stupid little micro-USB connectors in your camera are small, delicate, and fragile.

ANS: use a flash card reader.

The only time I use the direct camera connection is when I need to synchronise the clock.

Errr ... Dave, 3.5GB is nothing. Doing wildlife, I usually do 2-3 times that much a day if the birds are around and thelight is decent. If I shoot raw, it is more.

If you are getting camera movement (pretty much the only reason you'd take multiple-fire shots of non-action subjects with a short lens), you should get your shutter speed up higher. Increase the ISO and/or open the lens up a bit ..... or find better light, of course.
 

P5-133XL

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Rather than shake, as unlikely as it is considering previous comments, he could be dealing with exposure issues and bracketing...
 

ddrueding

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Will any f/1.2 lens be able to take better low-light pictures than any f/1.4 lens? Does focal length have anything to do with it? Considering aperture is measured based on focal length, I would need to assume that a 60mm f/2 would let in more light than a 50mm f/2. Is this why my lens is capable of f/3.5 @ 18mm and only f/5.6 at 55mm?
 

P5-133XL

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Will any f/1.2 lens be able to take better low-light pictures than any f/1.4 lens?

Does focal length have anything to do with it? Considering aperture is measured based on focal length, I would need to assume that a 60mm f/2 would let in more light than a 50mm f/2. Is this why my lens is capable of f/3.5 @ 18mm and only f/5.6 at 55mm?

f1.2 will allow more light in than a f1.4, and thereby allow a faster shutter speed. However, there are far more considerations than simply shutter speed in taking better pictures. Stuff, like the quality of the glass, the skill of the picture taker.

Focal length has nothing to do with the amount of light allowed in. Really it is closer to a magnification description. Given the same distance the larger the focal length, the larger the image on the film. However, focal length is not a true measure of magnification, because different lenses allow for different distances form the target. You will get a much different magnification factor at given focal length from a lens that the minimum focusing distance is 1 inch than from a lens that will focus, at a minimum of 1.8 meters.

Aperture is not based on focal length. in basic terms, the aperture is the diameter of the lens shrunk by a diaphram to allow more or less light in. The shutter also has to do with the amount of light let in: The faster the shutter travels, the less light is allowed in to expose the picture and that is why shutter speed and aperture are inversely related: The less light allowed in by the aperture, the slower the shutter speed needs to be to properly expose the photograph.

Is this why my lens is capable of f/3.5 @ 18mm and only f/5.6 at 55mm?

No, the reason for the difference in aperture is an internal design limitation for zoom lenses: It is far cheaper to make zooms that way, rather than as a constant aperture zoom (They do make them but they are typically very expensive and heavy). Aperture and focal length are not related.
 

ddrueding

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Thanks for the response Mark. I thought I had read that the f-stop is a ratio involving focal length, thanks for straightening that out. I know that there are many factors to taking good pictures, but my primary point of interest happens to push the technical limitations quite a bit.

I teach Argentine Tango, and often frequent Milongas (tango parties). These are notoriously dark, and the action is fairly quick. My current lens @ 18mm, f/3.5, and ISO 1600 requires 1/4th second shutter speeds to expose properly. In order to capture what I am after, I'm looking for a shutter speed closer to 1/60th. The camera can do ISO 3200, but for black background shots it is not pretty.

From what I understand, getting a lens that can do f/1.4 would allow an exposure that was about 7 times faster. Then upping the ISO to 3200 would get a shutter speed of 1/56th. So it is technically possible.

I know there is a lot more to getting good pictures, but I need to at least start with the right equipment.
 

P5-133XL

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I was incorrect. The larger the focal length, the less light per square inch is placed on the film. However, you don't have to worry about that: Just use the rated speed of the lens as your guide.

Your f-stop/shutter speed numbers are not quite right. I believe you are confusing 1/2 stop with full stop. See Wikipedia

for a constant ISO:

f3.5 1/4
f2.5 1/8
f1.8 1/16
f1.2 1/32
f0.9 1/64

basicly, divide the aperture number by the square root of two to double your shutter speed. You are not likely to find a lens faster than 1.0 ...

While technically, you could get a 1.2 lens and increase the ISO to 3200 to get your photograph at 1/60. However, It will be ugly at ISO 3200 because of the noise. A better solution is to increase the light level in the room, either by additional lighting, the sun, or a flash (or multiple flashes). Also, an IS lens will signifigently help with the hand holding shake: You can typically gain an additional 1-2 f-stops by going IS.

A tripod may help. If your subjects are moving it is much harder to properly frame your subject, but it does get rid of hand-shake. If you can predict where your subject will be then you can place the camera to get the shot. However, it all depends on how fast the subjects are moving when the shutter goes off: If the subjects are not moving too fast, you may be able to get away with 1/15th of a second.

A very small motion at the camera is effectively a very large motion at the subject. That is why the general rule is that one should not shoot with a shutter speed faster than 1/focal length of the lens was created. A tripod has no hand shake, so you are only dealing with the actual motion of the subject which, for humans, is normally far slower. Even, if you get some blur from their motion, you may like the effect because the background will not be moving and be totally sharp. An IS lens is only used to get rid of hand-shake and will not help dealing with a moving subject ...
 

ddrueding

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So, as far as fast lenses in Canon's lineup is concerned, her is what I am seeing:

EF 50mm f/1.0L - $2600
EF 85mm f/1.2L II - $1900
EF 50mm f/1.2L - $1400
EF 50mm f/1.4 - $350

Although I would love to get away with one of these:

EF 50mm f/1.8 II - $80

So I need to figure out exactly what I am sacrificing going from f/1.2 to f/1.4, and from f/1.4 to f/1.8. And (gulp) what I could gain by going to f/1.0.

Are there non-Canon lenses I should be looking at?
 

Handruin

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Another aspect to consider is that if you use a lens like the Canon 50mm F/1.4 @ F/1.4 the amount of picture in focus can be very small. I've taken pictures at F/1.4 only to find the tip of a person's nose in focus and their eyes are softly out of focus. Here is an example of my cat Zelda which reflects something similar to what I'm talking about. Her eye is in focus but her nose is not. If you bought a lens capable of F/1.0, the area would be even smaller.

Camera: Canon EOS 20D
Exposure: 0.006 sec (1/160)
Aperture: f/1.4
Focal Length: 50 mm
ISO Speed: 400
 

Handruin

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I don't know what that is...I have a "P" mode for portrait on my 20D.
 

Handruin

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You're right it does. I've never used it so I forgot I had it. It's a weird setting on the camera and I don't know how well it works.
 

P5-133XL

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It is a useful Cannon function to determine the aperture needed to get a specific depth-of-field. You, focus on the nearest object that needs to be in focus, followed by focusing on the farthest (you can reverse the order), and then focus on your intended focus point and the camera will report back the minimum aperture that is needed to make sure everything wanted will be in perfect focus. It will work with any lens. Of course, there is some electronic judgment is occurring, so some human interpretation can be good: The fiddle factor or simply experience can be invaluable here.

Once you have the needed aperture, you can deal with lighting, or changing out the lens and redoing, or simply re-choose what actually needs to be tack-sharp, to get the needed shutter speed and aperture combo to get the perfectly exposed photograph. People don't tend to use it because of the extra time, effort and planning and they don't feel the effort is needed. However, since DD is stretching the limits, I would argue that the extra effort is absolutely needed to be successful in his quest.
 

ddrueding

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Stretching the limits is right. Fortunately, I will have some time to set up the shots. This is a traveling dance, the couples move around the outside of the floor counter-clockwise. Typically there are tables set up around the perimeter (whose candle-light could be the only source). I plan on using a tabletop tripod on one of these tables, with the 7" LCD on my laptop for focus/motion judgment calls. We'll see how well it does.
 

ddrueding

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Wow, doing some basic DOF calculations does not bode well. I understand that using a fast lens close to the subject causes a very low DOF, but even at 12' distance, 50mm@f1.4 gives a DOF <1ft! Backup plan: Hyperfocal distance? Nope....not until 300+ ft.
 

ddrueding

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50mm@f1.8 only gets a little over 1ft DOF, but 35mm@f2 manages 2.75'. That would be enough.

Canon sells an EF 35mm f2 for a reasonable price (~$250).

Thoughts? Hopefully the local shop doesn't have it in stock, so I'll be able to read your responses before I buy it ;)
 

e_dawg

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Yes, I was going to recommend you shoot at higher (smaller) apertures too. Somehow my reply got lost in the ether...

I'd say 50/1.8 lens shooting at f/2.8 or 30/2 lens shooting at f/2 or f/2.8. Although some wouldn't agree with me, I find shorter focal lengths give you greater DOF for the same aperture in most situations ;)
 

ddrueding

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Local store didn't have any lenses in stock, and couldn't even order the 35mm/f2. Looks like MSRP is pretty fixed though, so I don't need to shop around?
 

P5-133XL

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Don't forget: When calculating DOF you need to multiply your lens's focal point by 1.6 because of the 20D's sensor size.
 
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