alec_myers

<p>I would use dishwasher salt (available from supermarkets) if I were worried about the idodide. From Wikipedia:</p>

<blockquote>

<p> Unlike the sodium chloride salt used for culinary purposes, the sodium chloride salt used for a dishwasher water softener does not have added impurities (such as <a title="Iodide" href="http://en.wikipedia.org/wiki/Iodide">iodide</a> salts). Additionally, salt used for dishwasher water softening systems must have minimal iron and manganese salt content, as these mineral ions tend to form precipitates that clog the ion-exchange resin.</p>

</blockquote>

<p>This page says you <strong>should </strong>ask for hand inspection of (amongst other things) film that you intend to push, and sheet film:<br>

<a href="http://www.tsa.gov/travelers/airtravel/assistant/editorial_1035.shtm">http://www.tsa.gov/travelers/airtravel/assistant/editorial_1035.shtm</a></p>

<p>I had no problems at Newark asking for a hand inspection. The TSA agent was only too pleased to get out the swabs. Which was by contrast to all the UK airports I've flow through where the agents are only too pleased to be difficult and obstructive. </p>

 

<p>Can someone confirm categorically that a photograph of a sculpture is considered a derivative work in the USA, please?</p>

<blockquote>

<p>The Leica seemed to have bright lines for focusing, and the entire frame seemed to shift left/right as I changed the focus ring.</p>

</blockquote>

<p>That's the parallax correction. Since the viewfinder is offset to the side of the lens and they both point forward, an object close to the camera which is centred in the lens is offset to the side of the viewfinder image. The brightline mechanism in Leicas moves the framelines as the focus distance gets closer so an object centred in the lens stays centred between the lines. Obviously the view of that object will be slightly more from the side in the offset viewfinder than the lens sees, but that can't be corrected for.</p>

<blockquote>

<p>Second, can someone explain the difference between a <em>rangefinder</em> and a <em>viewfinder</em> ?</p>

</blockquote>

<p>The viewfinder is the bit you look through; the rangefinder is the mechanism that superimposes a ghost image in the viewfinder and lets you adjust the focal distance to suit the subject. In some cameras the rangefinder is viewed through a separate window. For instance, even for leicas, very wide angle lenses have a separate clip-on viewfinder. The rangefinger mechanism in the camera body viewfinder window can be used for focusing, and the separate viewfinder gives you the framing.</p>

<blockquote>

<p>If this is the case, when dealing with cameras that have a built in viewfinder, what happens when you swap lenses?</p>

</blockquote>

<p>With Leicas, when you change lenses a lever in the lens mount causes a different one of several sets of fixed brightlines to appear in the viewfinder window showing you approximately the edges of the frame. You can also move a lever on the front of the camera to see different brightlines without having to change the lens. However the view in the viewfinder doesn't change; merely a different set of lines shows up; for a long focal length lens you end up 'ignoring' most of what you see in the viewfinder since the brightlines outline only a small central region of the view.</p>

<p>Bob's right. ICE only works because colour film dyes are transparent to IR. But the silver grains in b/w film aren't and are indistinguishable from dust particles.</p>

<p>Of course I can't think of a better way to encourage someone to nose around in and take copies of a set of pictures than to tell him or how how important it is that they don't copy them.</p>

<p>You don't want to use any automatic metering mode. </p>

<p>Sports areas have even lighting (or they wouldn't be suitable for sports). All automatic metering will do is underexpose when a white shirt fills the frame or use a shutter speed that's too long when a white shirt doesn't fill the frame. Either way, find the right exposure and stick to it. Automatic metering is only any use when the light falling on the subject varies from frame to frame. </p>

<p>The moon is a regular object (made mostly of rock) lit by bright sunlight (think about it) so the sunny-16 rule applies. That is, f/16 and 1/ISO for your shutter speed, in seconds. Most authorities recommend a stop overexposing by using f/11 instead as the moon is a fairly uniform dirty grey.</p>

<p>At f/8 and and ISO 100 the correct exposure of the moon is therefore about 1/200th.</p>

<p>Unfortunately, if you use a correct exposure to detail in the disc of the moon, the rest of your night scene will be rather dark, to say the least. But that's because of the terrific difference in luminosity between the sunlit moon and a night scene on earth, which your eyes do a good job of masking.</p>

<p>There's no way to make an image smaller (in pixel dimensions) without it being destructive. Fewer pixels = less information.</p>

<p>And increasing the size of an image isn't destructive (ignoring small rounding errors I suppose), regardless of the algorithm. What it does do is add in extra information interpolated from the existing data in the smaller image. The best way to do this is to break the image down into its frequency components (like by a fourier transform) then rebuild the image in a larger size from that data - which avoids or minimises adding fake extra information (artefacts). That's pretty slow though, and bicubic interpolation is just one of a range of different ways to approximate that. Wikipedia seems to have a reasonable page describing it. There's nothing fundamentally "best" about bicubic though.</p>

<p>When you talk about methods, do you mean in photoshop? I think that aside from user convenience, the actual sequence of clicks used doesn't make a lot of difference to the result.</p>

<blockquote>

<p>A police officer can only confiscate cameras, film and memory cards with a court order.</p>

</blockquote>

<p>I believe a policeman can seize what he believes to be evidence of a crime, be it photos on a memory card or anything else, no court order needed. Definitely he can't delete anything, and a security guard certainly can't seize anything at all. </p>

<p>You can rename drives, paths, folders etc, without disaster. I do it all the time. Lightroom is very very good at reconnecting moved files to the right catalog entry (although sometimes it needs prompting to the right folder for the first file). To be honest I don't bother re-locating all the files immediately after moving them, but only when I actually need to open or re-preview the file. The main thing is, don't panic, you won't lose any data or edits, or have to reimport.</p>

<p>It's relatively straightforward to do an exponentially weighted rolling average. However, I've noticed that when copying files from one drive to another Windows actually uses its random number generator instead.</p>

<p>As a rule of thumb, I have learned that, mostly, coveted and expensive light modifiers do usually have a significant effect that cheaper ones (or doing without entirely) can't quite match - which makes them worth having, and means that a high price can be charged for them.</p>

<p>A grid makes the light fall in a roughly parallel direction, it doesn't just reduce spill.</p>

<p>If your subject is close to the lightbox a grid makes each part of the subject be lit only by the portion of the diffuser that's close to that part, rather than from the whole surface of the lightbox. So yes, it will change the light a lot.</p>

<blockquote>

<p>And Alec also mentions "Diffusion is easy, the umbrellas are the diffuser" ...</p>

</blockquote>

<p>Actually that was the other guy, not me.<br>

I'm dubious as to whether it will work, but I'd like to hear, so please post back.</p>

<blockquote>

<p>...If you (the photographer) can shoot a wedding with 80 or 90 images <strong>total</strong> , and provide a 5x7 album of 16 to 20 prints, a two-hour wedding at $500.00 is not going to harm your bank deposit...</p>

</blockquote>

<p>... and I'd like strongly to dispute this point that the value of a set of wedding photographs, or what a photographer charges for them should be based around the quantity supplied. Imagine quoting $2000 (or $500) to photograph a wedding - then being asked by the client "well we can't afford that, shoot half as much and we'll give you $1000 (or $250)."</p>

<blockquote>

<p>I passed a uniformed and jack booted officer standing mostly hidden in a covered doorway with a submachinegun strapped across his chest. If you played Wolfenstein3D twenty some years ago, you have the right picture in mind.</p>

</blockquote>

<p>This cuts both ways. I am completely freaked when I have visited the US and <em><strong>absolutely everyone in uniform</strong></em> <strong><em>is wearing a side-arm</em></strong>. Even the border officers at the so called <em>Peace Bridge</em> in New York State. Totally bizarre, to me, even if I don't have a computer game to which to liken it. (Oh, and I think those border officers wear jackboots too.)</p>

<p>Sarah,<br>

I've read your response to Steve, above. Several times. Steve and I both feel that you'd misrepresented the state of play about photography and the law in our country. That might be a trivial thing to you but to us actually it's quite important. There is enough misinformation on the subject without you adding more to it here.</p>

<p>So, yes, I am actually pleased that you will now "<em>grant you that it is legal to take most types of pictures in the UK, as with anywhere else in the entire universe</em>", although disappointed that you feel the need to belittle and mock in your response. One wonders, if it is such a peripheral point (to you, that is - not to us) why you had to make such a song and dance about it.</p>

<p>As for the "other arguments" - I'll leave those to you.</p>

<p> </p>

<blockquote>

<p>Make no mistake here: I'm not arguing about which country is more virtuous. You're the one doing that.</p>

</blockquote>

<p>I'm not making a mistake. I'm simply telling you that British laws are a matter for the British electorate; not for you.</p>

<p>Just curious as to what a polarizer in front of a flash will achieve?</p>

 

<blockquote>

<p>An excellent example is your Digital Economy Bill, which could punch some very serious holes through international copyright protections if ratified.</p>

</blockquote>

<p>I'd say the US is way ahead of us, with your Orphan Works Act. Really Sarah, put your own house in order first.</p>

<blockquote>

<p>Any picture that pisses off a cop.</p>

</blockquote>

<p>Sarah, there's no law here against taking pictures that annoy policemen, and well you know it. There is some controversy about overzealous officials overstepping the mark - but that's about officialdom and not legislation, and in any event no different to the US - photo.net being full of threads to prove it. </p>

<blockquote>

<p>The British protestors have it right, IMO, and I hope they don't stop screaming about the erosion of their rights until those laws are repealed.</p>

</blockquote>

<p>Please worry about your own government's approach to legislation and leave us British to deal with ours. Your inaccurate characterisation and hyperbole is unhelpful to say the least.</p>

 

<blockquote>

<p>I'd be doing my photography despite these laws.</p>

</blockquote>

<p>I've read that page. Which laws exactly are you objecting to? The ones forbidding taking indecent photos of children? In fact, give me a circumstance where taking a photograph would be permitted in the US but forbidden in the UK please...</p>

<blockquote>

<p>I think the difference between the US and the UK in this regard is that the UK actually has more draconian laws impeding photography.</p>

</blockquote>

<p>Absolutely <strong>false</strong>.</p>

<blockquote>

<p>There are no UK laws impeding photography, just ill informed or over zealous police officers and security guards.</p>

</blockquote>

<p>Absolutely <strong>true</strong>. </p>

 

<p>... and air from a compressor designed for air tools has lubricating oil added. This benefits the tools, but does no good to the insides of a camera. It certainly isn't pure clean filtered air.</p>