jcoffin

June 6, 2012

The macro button is just a release to let you turn the zoom ring past the 28mm mark. You only need to hold it long enough to turn the ring. Once you've turned the ring, you can release it. You can then turn the zoom ring to simultaneously zoom and change focus, and with the button released, it'll prevent you from accidentally turning it back into the normal range.

April 24, 2012

A number of people have mentioned Maxtor and Seagate.

I think it's worth mentioning that Seagate bought Maxtor years ago. There are undoubtedly still drives in use that were made by Maxtor when they were a separate company, but they're getting fairly old now. The buyout happened something like 4 or 5 years ago if memory serves. As far as anything even close to new goes, Maxtor and Seagate are one and the same.

April 13, 2012

While I've never used a Reflex III, I did find the linked aperture and shutter scales a pain on my Retina.

They (just about all the Retinas) have a reputation for being difficult to work on, which probably helps account for the number you run into that don't work (or at least don't work quite correctly).

April 10, 2012

Just for grins I'll point to one other (unfortunately discontinued) lens that hasn't been mentioned: the Minolta 3x-1x macro. This is definitely a macro -- like the Canon MP-E, its most distant focus is 1:1, and close focus is 3:1 (where the Canon goes all the way to 5:1).

Some people have called this a zoom, but that's not really very accurate. It does change focal length but it's pretty much like the focal length change in almost any floating element or internal focus lens. You only have one control that changes the focus distance and focal length simultaneously -- and the change in focal length is fairly small anyway, going from about 52mm at 1:1 to about 45mm at 3:1.

This does have the distinction of being (sort of) the fastest dedicated macro lens around, at least to my knowledge. At 1:1 it's f/2.8, which is pretty typical. Thanks to the reduced focal length, however, at 3:1 it's actually f/1.7. Thanks to the extension factor, however, those are effectively about f/5.6 and f/6.7 respectively (and the camera only ever shows the effective aperture).

March 26, 2012

I'm also in the "use the vertical grip" group -- when I buy a new camera, I buy it with the vertical grip (or motor drive, if you look back far enough), generally mount it before taking a single picture, and pretty much never remove it. If the bottom of my camera was purple with pink polka-dots, there's a good chance I wouldn't ever realize it.

I do think the picture claiming one is right and the other wrong is pretty close to pure nonsense though. Just for fun, I just tried holding one without the vertical grip (hey, the bottom of the camera is black, just like the rest!), and to me there's no question: what it claims is "right" is extremely clumsy. Despite theoretically being able to brace both hands against my chest, with a longer lens the camera feels quite unbalanced and unsteady. If I hold the button on the bottom, it's much more comfortable with the left hand around the top.

I do think turning clockwise or counterclockwise is largely a matter of which eye dominates -- though with plenty of eye clearance, it might not be nearly as big of an issue. Either way, however, it seems to be generally quite clumsy to try to hold both hands on the same side of the camera -- they're pretty much designed for one hand coming from each side, and holding them vertically doesn't seem to change that much (if at all).

Nonetheless, all the others are compromises -- a vertical grip is the only truly "correct" answer.

March 23, 2012

I have to disagree with the claim that all the photographs are technically good. Even ignoring posing and/or lighting, there are a couple that look to me like even at the most basic level, simple things like exposure and/or focus weren't really what anybody would or should hope for.

Beyond that, the lighting is highly variable. Several have extremely harsh lighting, in at least a couple of cases looking like the most basic on-camera flash, with no attempt at modification at all. In a couple of cases, those are even in portrait mode, leaving harsh shadows outlining one side of the model. Avoiding that isn't a matter of great artistry, it's just a matter of having at least some clue of the basics. At the same time, a couple have lighting so flat it makes the model look completely two-dimensional.

March 16, 2012

Mike: Yes, this was shifting the camera. I've done both, and generally prefer to shift the camera when possible, but without a macro rail, it's not always the easiest thing to manage.

March 15, 2012

To give an idea of how thin depth of field can get in macro shooting, consider this shot: <img src="http://i1212.photobucket.com/albums/cc452/jcoffin01/strawberry.jpg" alt="" width="1000" height="800" />

This is at a ratio of only something like 1:2 or so. Even at that, I stacked 12 shots to cover the depth of the strawberry. Despite this, some of the more distant parts (e.g., some of the leafy greenery) still aren't sharp.

As the reproduction ratio goes up, the depth of field drops even more. Many of the pictures you see of insects and such are really 20+ shot stacks. One way to get an insect standing still long enough to do that is to go out early on a really cool morning -- being cold-blooded, they slow down as the temperature drops.

March 5, 2012

A few from February:

Pikes Peak in the mist.

Glider on tow near sunset.

Some seed heads

The ultimate: a chocolate tort

February 29, 2012

Just to add a little more mud to the water: JPEG isn't really a single format -- it's a whole group of formats. The format that's used the most often is, indeed, lossy as others have noted.

There are also, however, two JPEG formats (lossless JPEG and JPEG-LS) that do lossless compression. Despite being lossless, both of these are still (usually) more effective than LZW- or ZIP-compressed TIFFs, for the simple reason that they use compression specifically designed for pictures (where ZIP and LZW are quite general-purpose compression algorithms being applied to picture data). There's also a "low loss" version of JPEG-LS that does lose a little information, but not very much. If I recall correctly, it's also not progressive like normal JPEG, so re-saving the data repeatedly won't increase losses.

JPEG-2000 also includes a wavelet based algorithm. One variant of this uses only integer math, giving precise transformations from input to output, so it can also be used for lossless encoding, if desired. It works pretty well for many real photographs, but not usually as well as JPEG-LS for synthetic pictures (i.e., things like charts and graphs).

For better or worse, however, none of these has ever been used much though. At least In my opinion, they've been victims of their predecessor's success -- the original JPEG was good enough that most people don't seem to see much (if any) reason to start using anything else. If anything, lower costs of hard drives and network bandwidth make them even less interesting over time.

February 28, 2012

You normally want to set the exposure and white balance from the card, then do what your camera requires to lock those, pull the card out of the way and take the picture.

This is because the camera doesn't know what color or how bright your yarn (or whatever else you put in front of it) should be. On auto exposure, it takes a guess that whatever's in front of the camera averages out to roughly a neutral gray. In most cases that's a fair guess, but in this one it probably isn't. Therefore, you have to set up the camera *using* the neutral gray it's looking for, under the light you'll be using, then using those same settings take a picture of the real subject.

I suppose I should add that most modern cameras do have a little more "smarts" about how they deal with exposure than just trying to get neutral gray average. Unfortunately, most of those "smarts" assume you'll mostly be taking pictures of people, and assume that most of what they have to compensate for is different lighting conditions (especially common but lousy conditions like outdoors in bright sunlight). Most of them generally won't do much for a subject like this that doesn't resemble a person at all.

February 28, 2012

US Patent number 2,205,860 shows a portable tent-like more-or-less softbox (in both rectangular and octagonal varieties). This patent was filed September 29, 1939.

I should add that while this shows tent-like construction, the lighting itself looks closer to a beauty dish than a soft box -- there's a reflector directly in front of the bulb to reflect light back at the "dish" part and prevent hot-spots. As far as I can see, it doesn't show any diffuser cloth across the front.

February 28, 2012

I believe the correct answer is "yes".

Seriously, there's really no way to rule one as categorically better or worse than the other.

February 28, 2012

Okay, I'll go out on a limb and suggest playing -- real playing, not just post processing.

Playing is a time-honored way of learning; in fact, I'd tend to say that when you get down to it, most real learning comes from a game in some way or another. The most successful students tend to be those who can invent a mental game to play, in which the object of their game coincides with the goal of the class.

Fortunately for you it's a lot easier to make a game that's fun out of photography than (say) learning the difference between a participle, a gerund and an infinitive.

A great deal will also depend on the age of kids you're dealing with. The younger they are, the most guidance they need to keep the game constructive, and not just running around in circles. For the youngest, you'll typically need to provide a lot of structure to the activities to keep it from degenerating into chaos. 12 year-olds will definitely still need some guidance, but benefit from a little freedom to express themselves too.

One activity that I've found rather useful is basically a treasure hunt, but instead of collecting items along the way, they need to take particular pictures. With a little careful structuring of the requirements, you can use the pictures to teach basics of composition. One (for example) might require two pictures, both with object X sharp, and one with object Y also sharp, the other with object Y blurred.

Others will simply require objects A and B in the frame, but not X or Y. These can progress from pretty obvious ones where you just point the camera in the right general direction, and work up to requiring considerable care to find the right spot to get the required subject matter while still eliminating the undesired objects in the background.

The first is obviously a lesson in apertures and depth of field, and the second in framing/position/angles and (possibly) focal lengths.

At least in my opinion, the challenge isn't to balance learning with playing, but to combine the two so the students not only learn, but enjoy doing it. If you want to think in terms of balance, I'd say the primary balance is between structure and freedom of self expression. 12 year olds are right at the point that you need to balance the two pretty carefully -- you still need to guide them quite a bit, while still giving at least a reasonable room for some self expression. This is one way the game aspect is helpful -- they're sufficiently accustomed to games having rather arbitrary rules that you can impose quite a bit of structure this way, and as long as they're applied fairly, they'll put up with quite a bit that would bother them a great deal more if it was just a general requirement instead of a rule of the game.

February 28, 2012

At least as I read it, going from left to right you have f/3.5 (or f/3.6 to be technically accurate), f/8 and f/16. Going from top to bottom in each chart, you have 10, 20, and 40 line pairs per millimeter.

And yes, it looks like the top row of charts is focused at infinity, the second row at ~20 meters and the bottom row at ~6 meters. My guess as to why they did this is pretty simple: because the performance when focused and infinity doesn't tell the whole story -- especially with a wide-angle lens, you frequently have quite a bit of depth in the picture, and they apparently thought you might want to know how that would/does affect resolution/contrast.

February 27, 2012

Nikon has had "LTE" in place for decades under the name "F mount".

For those who didn't know, "LTE" in phones stands for "Long Term Evolution" -- the basic idea was/is to have a coherent long-term plan instead of basically starting over from the beginning with completely new protocols every generation (as they did with Analog, PCS, GSM, and 3G cell phones). There is a bit of a dichotomy there though: the technical people would like to get rid of "generations" and have more compatibility -- but the marketing people really like having distinct generations as a basis to tell everybody their current equipment is obsolete.

And now back to your regularly scheduled flaming... :-)

February 26, 2012

I think Bill Tuthill is pretty much right. The only native E-mount macro is a 30/3.5 that's quite mediocre. If you want to shoot macro with a NEX-7, you pretty much need to plan on using some other mount of lens with an adapter. The good news is that there are lots of cheap adapters. The bad news is that at least as far as I know, the only EOS mount adapter worth getting is pretty expensive. On the other hand, there are quite a few other adapters to let you use Sony's A-mount lenses, Leica, Contax, etc.

Oh, the A900, A850 and D3x can also beat the NEX-7, at least in practice -- but it depends on the lens and aperture you use. Since they're all full-frame, they put more stress on the edges and corners. The A77/A65/NEX-7 are APS-C, so the extreme edges/corners get cropped, but you need even higher resolution toward the center.

Based on actual experience, the full-frame models win around 80% of the time, the APS-C models about 10% of the time, and the rest are essentially a tie. Given the price difference (especially for a D3x) there's no question that the APS-C models win on performance/price basis though (and, of course, when you want something smaller/lighter than a 5D2, the other full-frame models aren't really candidates anyway).

February 21, 2012

The work on your web site looks nice, but that doesn't tell much about what it would be like to work with you doing wedding photography. At least from my perspective, wedding photography has to be divided between the part during the ceremony, and everything else.

During the ceremony, your primary job is to be unobtrusive -- be in the right places at the right times to ensure that you get the shots you need. Most of the in-ceremony pictures are, however, fairly unexciting photographically. As I said, the big thing is to get to the right places without interrupting the ceremony itself. A great deal of that consists of going to the location ahead of time to figure out where you want to be at different times, and consulting with the priest/minister to find his/her preferences, requirements, etc., about what you can do.

Most of the rest is really primarily about managing large groups of people. At least in my opinion, managing the group is the most important skill -- getting people where you want them, when you want them, posing nicely when they do, and so on. Quite a few of them (especially brides and mothers of brides) are already under severe stress. Ideally, you need not just the competence and confidence to do your work, but need to be so obviously good at what you're doing that just being around you helps relieve their stress and worry.

I certainly don't mean to imply that you're weak at that -- only that it's impossible to guess from a portfolio whether you are or not. Working with models (for example) is generally quite different, so there's almost no way to guess how well you can/will handle that part of wedding photography.

February 21, 2012

If you have it available, you want a separate flash on the background to minimize shadows.

Otherwise, you generally want to raise your flash somewhat higher than the camera, so the shadows fall behind people's bodies where they're (mostly) hidden.

February 20, 2012

In this case, the loss to film is a major win for patients though. The digital sensors let them reduce your exposure to X-rays to something like one tenth what they used with film (and as sensors get better, it'll probably continue to drop).

February 17, 2012

Andy: no, most of the counts in the Apple v. Microsoft case were dismissed on the grounds that Apple didn't own what they were suing over. Many at the time really hoped the court would make some sort of determination about the limits of copyright protection, especially over look and feel types of things (which is most of what Apple was claiming). The court did note that it seemed that Apple was trying to get patent-like protection from copyrights. When it came to the ruling, however, the court took what was (at least legally) a simple, safe, non-controversial course: Apple couldn't sue over theft of things that didn't belong them in the first place, so the cases were dismissed.

Xerox was prevented from asserting their rights that would normally stem from the ownership, but that doesn't make Apple's action any less stealing. For comparison, consider if I stole your car, and kept it hidden until the statute of limitations ran out. I could no longer be prosecuted, but what I did is still clearly theft, and just as clearly unethical and dishonest.

While I'm not at all convinced that Apple has any legal liability for their actions, I'm not at all convinced that most of what they've done is honest or ethical either -- and I think the records from the court cases tend to support that position.

February 17, 2012

Actually, Xerox couldn't sue Apple over patent infringement with their GUI, because the US patent office didn't accept patents on software at the time (treating them as equivalent to mathematical equations, which cannot be patented).

It wasn't until 1981 that the US Supreme Court (in Diamond v Diehr) ruled that a patent could apply to a device, even though some of what that device did happened under control of a computer.

In addition to that, due to its early monopoly position in the copier market (i.e., Xerox invented the whole concept of the modern copying machine) the US FTC issued a consent decree that placed severe limits on what Xerox could patent, and the degree to which it could enforce any patents it did receive. Even though this was really only intended to cover copiers, it was written (or at least interpreted) to include any sort of device that could produce printed output -- including essentially any/all computers.

Apple did, however, sue Microsoft over supposedly infringing their intellectual property rights in their GUI (in 1988). The court dismissed all but one of those claims, some (most?) of them on the grounds that they weren't original with Apple. Only one claim ended up being enforced (which is why Microsoft calls it a "recycle bin" instead of a "garbage can" -- it appears that using the image/name of a garbage can was original with Apple).

I also feel obliged to point out that when the Apple LISA (predecessor to the Macintosh) came onto the market Xerox most certainly did have GUI-based computers available for sale. Xerox put the Star (officially, the "8010 information processing system", or something equally catchy) on sale starting in 1981. They were still developing and offering GUI-based systems for sale until after the Macintosh was on the market (e.g., the Xerox 6085 was introduced in 1985). The claim that Apple was just doing the job because Xerox was just sitting on the technology without turning it into commercial products seems to be entirely unjustified.

Finally, there was a case (in 1989) in which Xerox did sue Apple for infringing on their intellectual property. This case was dismissed on legal grounds (primarily statute of limitations). Even Apple never really attempted to claim that they hadn't pretty much stolen the technology from Xerox -- only that by then they'd gotten away with it long enough that Xerox had lost the opportunity to stop them.

The claim that Xerox was compensated for the user of the GUI seems a bit of a stretch as well. Apple did license some elements (basically individual images they used in the GUI) from Xerox, but quite clearly did not license the technology of the GUI itself.

To summarize: while I might tone down the rhetoric a bit from words like "theft", Apple's ethics and honesty in the area do seem rather questionable, at very best.

February 16, 2012

A lot of people are currently getting this kind of result by using a medium format camera with a leaf shutter. Most leaf shutters will X-sync at all shutter speeds -- the newest are doing 1/1600th of a second X-sync.

Coupled with the most recent studio flashes that have relatively short flash durations (e.g., Paul Buff "Genius" series), you can use a fairly large aperture to get a lot of light from the flash, but a fast shutter to reduce the contribution from the ambient light (e.g., to get the relatively dark sky).

Of course, it's possible to go a bit overboard with this -- I've seen a few demonstration pictures that look almost like they were taken at night, with the subject brightly lit, but the sky essentially completely black even though they were taken in broad daylight.

February 14, 2012

It's been said quite a few times about a number of different circumstances, but I believe it's universally incorrect.

The emulsion is on the front of the film. What changes in 220 is the thickness of the layer(s) behind the emulsion (specifically, 220 only has the paper backing at the very beginning and end of the roll, where 120 has it for the full length of the roll).

The pressure plate of a 220 back has to accommodate the thicker region with the paper backing. The pressure plate for 120 probably has enough spring movement that it would move forward that little extra amount to keep pressure on 220 film. The obvious place there could be a difference between the two would be some extra lubrication of some sort on the 220 to assure against scratching the film since (for most of the roll) there's no paper between the pressure plate and the film base. To be honest, I find even that fairly doubtful though.

That's not to say that I'm advising use of 120 in a 220 back (or vice versa), only that the supposed change in focus makes little or no sense.

February 13, 2012

To expand a little bit on the previous statements, I'd advise that you take Hector's advice (pay no attention to that post) and apply it equally to everything Ken Rockwell writes.

Much of what KR writes I'd classify as photographically-oriented science fiction. It combines a few facts with a lot of creativity to produce something that may be entertaining, but any relationship to reality is mostly incidental.

In this case, however, he seems to have departed from science fiction into pure fantasy, without even a hint of fact to form the basis for what he writes.

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Posts posted by jcoffin