kevin_schoedel

There is one (current version of the) DNG format (described <a href="http://www.adobe.com/products/dng/pdfs/dng_spec.pdf">here</a>). The specification allows for a number of variations in how the raw image data is stored, since not all cameras have the same kind of sensor. As the message says, the raw image data can be stored either in CFA form (for cameras with Bayer type sensors) or in linear form (for Foveon or triple sensors, or for processed images). The implication of the message is that Lightroom does not read some valid DNG files, which sounds a bit dubious.

Canon (USA):

<blockquote><b>Copyright</b></blockquote>

<blockquote>Copyright laws in your

country may prohibit the use of your recorded images of people and certain

subjects for anything but private enjoyment. Also be aware that certain

public performances, exhibitions, etc., may prohibit photography even

for private enjoyment.</blockquote>

<p>

Nikon (USA):

<blockquote><b>Notice Concerning Prohibition of Copying or Reproduction</b></blockquote>

<blockquote>Note that simply being in possession of material

that has been digitally copied or reproduced by means of a scanner,

digital camera, or other device may be punishable by law.</blockquote>

<blockquote><b>Items prohibited by law from being copied or reproduced</b></blockquote>

<blockquote>Do not copy or

reproduce paper money, coins, securities, government bonds, or local

government bonds, even if such copies or reproductions are stamped

"Sample."</blockquote>

<blockquote>The copying or reproduction of paper money, coins, or

securities which are circulated in a foreign country is prohibited.</blockquote>

<blockquote>Unless the prior permission of the government has been obtained, the

copying or reproduction or unused postage stamps or post cards issued by

the government is prohibited.</blockquote>

<blockquote>The copying or reproduction of stamps

issued by the government and of certified documents stipulated by law

is prohibited.</blockquote>

<blockquote><b>Cautions on certain copies and reproductions</b></blockquote>

<blockquote>The government has issued cautions on copies or reproductions of

securities issued by private companies (shares, bills, checks, gift

certificates, etc.), commuter passes, or coupon tickets, except when

a minimum of necessary copies are to be provided for business use by

a company.</blockquote>

<blockquote>Also, do not copy or reproduce passports issued by the

government, licenses issued by public agencies and private groups, ID

cards, and tickets, such as passes and meal coupons.</blockquote>

<blockquote><b>Comply with copyright notices</b></blockquote>

<blockquote>The copying or reproduction of copyrighted

creative works such as books, music, paintings, woodcuts, prints,

maps, drawings, movies, and photographs is governed by national and

international copyright laws. Do not use this product for the purpose

of making illegal copies or to infringe copyright laws.</blockquote>

Got that?

A corrupted JPEG file is usually unrecoverable. You could post one of them to see whether someone can estimate whether a recovery service might be able to help.

Jim, originally, CHDK had to be manually loaded every time the camera was turned on; it now can be made to start automatically.

 

Besides RAW, live histogram, etc. it provides a scripting language, which I don't think is present in any consumer cameras otherwise. Among other things this has been used for focus bracketing to take macro photos with wide DOF; this makes me slightly regret selling my A630.

The A650 has IS, but on the other hand, the A630 and A640 are supported by CHDK for extra features like RAW, live histogram, bracketing, etc. The A630 is around $200 now and the A640 around $250; the A650 is brand new and lists for $400.

 

I don't think there's anything else current that provides manual controls, optical viewfinder, and rotating display; the first two are rare in this range.

For an XTi, you could use an IR remote repeater, as sold for home entertainment devices. (A 90' cable should also work.)

On the cheaper end, on the Canons with CHDK (A610 - A640, A700, A710IS, S2IS, S3IS) you can define a square (or any other) mask or grid on the LCD.

Check your local dollar stores for jar openers.

I have a Pentax-M 28/2.8, and no objections to it.

<p>

<a href="http://www.takinami.com/yoshihiko/photo/lens_test/pentax_28-30.html">These tests</a> suggest the -M 28/2.0 has the best resolution.

<p>

I have encountered a couple of body/lens combinations in which the aperture actuators don't always engage properly. Check whether either is bent. Also check that the battery contacts haven't corroded.

The late, Chinese-made K1000 has the top and bottom case panels made of plastic rather than metal; that's about all. I once got a broken Chinese K1000 for parts, and there is no major difference to the internals. It won't be worth as much as a Japanese one if you sell it, but for actual photography they are the same.

 

The shutter is loud compared to newer cameras with metal leaf shutters, but should not be significantly louder than other cameras with cloth shutters, and should sound smooth. If it has been sitting unused for years, lubricants might have dried out. Likewise, if the foam light seals are the originals they are probably disintegrating.

<p>

There is one good reason to scan a black and white negative as colour -- but perhaps only for some scanners. The light sensors in every contemporary consumer film scanner, CCDs, are not actually quite up to the job. They randomly make minor errors: sensing a point a little lighter or a little darker than the true value. This is what is referred to as "noise"; it looks like static on a poor TV picture, if it is bad enough. (The effect is worst at low levels, i.e. in dense parts of the negative, which is why some people suggest developing for low density if you intend only to scan and not print optically.) Some scanners have an option that scans the film repeatedly, at least three times, and averages the results: since the noise is random, it (usually) doesn't happen in the same way in the same pixels every time, so the effect is to largely cancel it out.

<p>

Now, there are two ways that a scanner, told to scan black-and-white, could operate. One way is for the scanner to use a single colour channel (typically the green one) to determine the gray level. If your scanner does that, you are better off scanning in colour. When you scan in colour, you are getting all three colour channels (red, green, blue) at once, so you are effectively getting the equivalent of a triple-pass scan in one. (Actually, it's not quite that good, since the blue channel tends to have significantly more noise, but Photoshop's default conversion to grayscale happens to take this into account by giving the blue channel less weight -- not because the blue channel is noisier, but because, coincidentally, the eye is less sensitive to blue.)

<p>

The other thing a scanner could do, when told to scan black-and-white, is to scan using all three colour channels, and combine the results. This if effectively identical to scanning in colour and converting to grayscale in Photoshop, so if your scanner does this, there is most likely no benefit to scanning in colour. I don't know which, if any, scanners do this; I'm pretty certain mine doesn't. (Actually, with the (out-of-date) scanner I have, there is a good reason <i>not</i> to scan in colour, but I won't go into that here.)

<p>

I can't see any reason to scan as a positive (slide) rather than a negative, unless, as Scott says, it helps trick your scanning software into behaving itself.

<p>

OK, now I've read your description of the thermometer, posted while I was writing. There isn't a simple reference at these temperatures, other than another thermometer.

</p>

<p>

If you don't have access to an accurate reference thermometer, here is a method that is relatively cheap and most likely good enough for development, given the variations that differences in agitation technique and so on could cause. Go to a 'dollar store' or similar place, and find a rack with a dozen or more cheap and nasty glass thermometers -- best if there are different varieties. You'll probably find that adjacent thermometers disagree with each other by a few degrees. Lay out all the thermometers in a row, arranged in order from the lowest reading to the highest. The ones in the centre of the row will probably agree to a fraction of a degree; buy the middle one.

</p>

<p>

I've read somewhere that some (?) oral thermometers are actually offset from the true temperature to account for a difference between mouth temperature and internal body temperature, but I don't know whether this is true.</p>

<p>Actually, to check at 0°C, wait until some of the crushed ice has melted, or alternatively, add a little cold water and wait a few minutes for it to cool. Then clear a space in the middle of the ice, and put the thermometer in the liquid water, <i>not</i> touching the ice. The temperature of the ice could be below 0°C -- say perhaps -10°C if taken from a home freezer -- but the water can't be below 0°C, or else it'd be ice. (It can't be significantly above 0°C either, while surrounded by ice.)</p>

<p>If you have already been using a different thermometer for development, or you can borrow one, then it would probably be simpler to adjust this thermometer to the other <i>at the temperature(s) you actually use</i>, e.g. 20°C. Even though the other thermometer might also be also off, you can still use the same developing time and conditions as with it, and expect the same results.</p>