LED advice

[Penners]

Digital cameras and camcorders have auto and manual white balance settings for each that adjusts what the sensor records as pure white in each circumstance. If you set your white balance to "tungsten" and take a picture outside it will have a heavy blue cast - if you set the camera to outdoor and use it without flash under tungsten lights you get a very orange cast.

The trick is to shoot in RAW format. With the right software (Photoshop, for example) you can then muck about with the white balance setting (and a host of other things) after the shot has been taken. It's not quite as effective as getting your white balance right pre-shot, but it's not far off.

 

[Flyfisher]

but isn't sunlight a much wider-spectrum light source...?

In my ignorance, I have always assumed that sunlight includes every wavelength of visible light, ultra-light and infra-light in the known universe. Isn't that the case?

Perhaps (I'm not sure about "every wavelength"), but the intensity certainly varies a great deal across the spectrum, which is why different stars can have different colours. If you look at the Orion constellation you'll see that the top-right star is distinctly red (Betelgeuse - a red giant) and the bottom-left star is very bright (Rigel - a white dwarf) - I think that's the right way around from memory, but no doubt Google will confirm.

My understanding is that stars change colour as they 'age' and 'burn' different fuels. Our sun is currently 'burning' hydrogen but that will eventually run out and heavier elements will provide its energy, which will result in a different spectrum - or, rather, a different distribution of energy across its spectrum. Our atmosphere also has a big impact on the received spectrum due to various constituents absorbing various parts of the spectrum.

http://en.wikipedia.org/wiki/File:Solar_Spectrum.png may be of interest for those in possession of a suitable anorak.

 

[philpjuk100]

Opened it up,it stinks! very simple,input straight through a diode bridge and then an electolytic capacitor to smooth it then dropped through a couple of resistors and on to sixty led`s in series.No internal fuse!The electrolytic had "exploded" but I am still not sure why it turned off unless the heat had damaged a joint on the board.Now replaced it with a CFL but I have also had trouble with them as well! phil.
Ah! now I know why we had a "mystery" smoke alarm event from the alarm located in the same stairwell a few nights ago.

 

[Penners]

Our atmosphere also has a big impact on the received spectrum due to various constituents absorbing various parts of the spectrum.

Quite so, hence the importance of differentiating between "sunlight" and "daylight". The former being visible only in space.

 

[MdB]

The suns output is close to that of a perfect blackbody. This means that it does generally output light at all wavelengths. There are a few buts though - first there are various absorption lines in the spectrum where hydrogen and helium get in the way so there are various notches in its output. Secondly the atmosphere also does a good job of modifying the spectrum as well. Finally, a blackbody spectrum is anything but flat. In the UV range the output goes off a cliff with not much being output below around 200nm. The atmosphere also does a good job of blocking below 280nm anyway. At the higher end, the blackbody curve has a far more gentle roll off so the sun will be chucking out infra red, terahertz, microwave and radio waves the same way as you or I do.

To sum it all up, here is a pretty graph:

 

[Lime]

Opened it up,it stinks! very simple,input straight through a diode bridge and then an electolytic capacitor to smooth it then dropped through a couple of resistors and on to sixty led`s in series.No internal fuse!The electrolytic had "exploded" but I am still not sure why it turned off unless the heat had damaged a joint on the board.Now replaced it with a CFL but I have also had trouble with them as well! phil.
Ah! now I know why we had a "mystery" smoke alarm event from the alarm located in the same stairwell a few nights ago.

The internals of nearly all modern eco lamps have no protection whatsoever.
They rely on the heated/failed parts to be small/limited in size and the plastic to be fire resistant.
The same can be said of almost all plug transformers fitted to low voltage equipment such as phones, cameras and other gadgets.

 

[Penners]

At the higher end, the blackbody curve has a far more gentle roll off

That reminds me of someone - can't think who.

 

[AMc]

The trick is to shoot in RAW format. With the right software (Photoshop, for example) you can then muck about with the white balance setting (and a host of other things) after the shot has been taken. It's not quite as effective as getting your white balance right pre-shot, but it's not far off.

My understanding was that RAW simply grabbed whatever the sensor was seeing at the time so you could adjust anything except the physical exposure, ISO setting and the focus/aperture. I'd assumed that the white balance was arbitary and you could tune it to your hearts content?
I've been tempted to try RAW on my "Dad camera" (Pentax DSLR) but I've been put off by the extra storage space needed (hard drives are almost full, case has no space for more so I'd have to move and upgrade) and the requirement to fiddle with every shot just to make it viewable on the PC.

The main thing I need to do to improve my photography is to slow down and take fewer, better shots

 

[Penners]

My understanding was that RAW simply grabbed whatever the sensor was seeing at the time so you could adjust anything except the physical exposure, ISO setting and the focus/aperture. I'd assumed that the white balance was arbitary and you could tune it to your hearts content?
I've been tempted to try RAW on my "Dad camera" (Pentax DSLR) but I've been put off by the extra storage space needed (hard drives are almost full, case has no space for more so I'd have to move and upgrade) and the requirement to fiddle with every shot just to make it viewable on the PC.

The main thing I need to do to improve my photography is to slow down and take fewer, better shots

You're right that a RAW file is the unprocessed output from the sensor. But in good RAW-handling software you can adjust the exposure, as well as a host of other things. But you're right that you can't, of course, change the ISO, focus or aperture.

RAW files are indeed larger than, say, jpegs - the latter having been compressed within the camera. So RAW is storage-hungry. But you don't have to fiddle with a shot to make it viewable on your PC, provided you have a fairly recent version of Photoshop. You may need to download a free plug-in, though. There's also a free download to make them viewable with Windows Photo Viewer.

I have my camera set to save all shots simultaneously in RAW and jpeg. That way I have the jpeg for quick, unedited sharing with others, but I have the RAW for some creative Photoshop editing, should I so wish. But if you're short of hard drive space, I wouldn't recommend this!

 

[Flyfisher]

With external Terabyte hard drives now around £45 and internal drives costing nearer £30, there's little excuse to let a PC run out of storage space these days.

 

[AMc]

With external Terabyte hard drives now around £45 and internal drives costing nearer £30, there's little excuse to let a PC run out of storage space these days.

My excuse - it's not a good one - is laziness
I have a 250GB primary and a 160GB secondary and manually mirror my photos on both to provide some protection against a hard drive failure (or user error with the delete key). Other stuff lives on one or the other not both
I've recently added another 2TB PC elsewhere and a wired network so it is finally practical to move things around and replace the secondary drive - but I just haven't got to it yet. Still pondering replacing my 6 year old Dell PC entirely but funds are limited and I hate buying PCs as you always feel like what you've bought is superseded as they put it in the box

I have my camera set to save all shots simultaneously in RAW and jpeg.

Just had a look and my Pentax K100D only has 3 JPEG options OR RAW not both

 

[Penners]

Just had a look and my Pentax K100D only has 3 JPEG options OR RAW not both

In which case I agree that shooting mainly in jpeg is the more convenient option. But if you're taking a "special" shot, aiming for a creative result, you could always switch to RAW for that one.

 

[Penners]

I hate buying PCs as you always feel like what you've bought is superseded as they put it in the box

That is, of course, absolutely true. Just as it's true of pretty well any technical appliance - TV, washing machine... you name it. "Trickle upgrading" is the way that manufacturers cunningly keep demand going.

For example, do we honestly believe that the omission of a camera from the iPad 1 was the result of technical shortcomings?

 

[Flyfisher]

With external Terabyte hard drives now around £45 and internal drives costing nearer £30, there's little excuse to let a PC run out of storage space these days.

My excuse - it's not a good one - is laziness
I have a 250GB primary and a 160GB secondary and manually mirror my photos on both to provide some protection against a hard drive failure (or user error with the delete key). Other stuff lives on one or the other not both
I've recently added another 2TB PC elsewhere and a wired network so it is finally practical to move things around and replace the secondary drive - but I just haven't got to it yet. Still pondering replacing my 6 year old Dell PC entirely but funds are limited and I hate buying PCs as you always feel like what you've bought is superseded as they put it in the box

I sympathise entirely. But sadly, despite what the manufacturers may say, PCs require a fair bit of maintenance to keep them in tip-top condition and, depending on how they are used, can very quickly become completely indispensible. Glad to hear you have two of the things though. I reckon that's a minimum for anyone who depends on a PC such that a breakdown would really leave them in the lurch. Plus, it's almost impossible to fix a PC without access to the web from another PC anyway!

 

[Penners]

PCs require a fair bit of maintenance to keep them in tip-top condition

Are you talking about soft- or hardware maintenance, FF? The only hardware maintenance that I can really think of is a good clean-out of dust (which can, worst case, cause overheating) on infrequent occasions.

As for software maintenance, thank you for the reminder. It's high time I ran CCleaner again.

 

[Flyfisher]

I was thinking about the software. I agree with you that the hardware rarely needs anything more than a bit of a clean (though mine are lucky to get that) but run them 'out of the box' and they soon get clogged up with junk. I've used Ccleaner for years and it seems to do a pretty good job. I also think of backups and general organisation of 'stuff' as maintenance but, even so, I'm not very good at tagging all my photos so it can sometimes take quite a bit of time to find a specific one. All of which is more 'maintenance' - or possibly better described as 'admin'. Whatever it's called, it's frightening how easy it is to completely lose an hour or so when using one of these indispensible 'productivity tools'.

 

[Penners]

I'm not very good at tagging all my photos

Me neither, with knobs on! I have about 85GB of photos stored on my hard drive. They're in many dozens of folders, all called by cryptic names which made complete sense to me... when I originally filed them.

 

[AMc]

I'm not very good at tagging all my photos

Me neither, with knobs on! I have about 85GB of photos stored on my hard drive. They're in many dozens of folders, all called by cryptic names which made complete sense to me... when I originally filed them.

I only have 20GB of photos and I've never tagged any of them because I've not seen any consistency in how the tags are looked after across image packages and don't want my whole collection locked into one package - which has tripped up friends when they've moved computers.

I use folders based on which of my cameras I used, then I file by date which makes it reasonably fast to find what I'm looking for.

My Canon camera & software keep sequential image numbers across downloads and saves to dated folders which accounts for the bulk of the snapshots - so I end up with C:\Pictures\Canon IXUS 870IS\2011_04_24\IMG_1991.JPG.
My Pentax DSLR has terrible transfer software so I manually copy across using a similar structure. The camera itself makes dated folders and starts at IMGP0001.jpg EVERY DAY which is incredibly annoying. Once I've moved images I end up with C:\Pictures\Pentax K100D\2011-03-21\IMGP0003.JPG

Then I pick the best ones out and copy them to a "Best of 2011" folder (that's when having dozens of IMGP0001.JPG files gets really irritating).

The "Best of ..." folders I upload to a http://www.photobox.co.uk account for printing. That gives me an online back should something terrible happen.
I'm then trying to do a bulk resize to get them onto a memory card for my digital photo frame.

Finally I mirror the folders onto the 2nd drive in this PC and onto another PC on the network so I have a copy in 3 places at any time which makes it less probable that I'll lose all my photos.
I used to copy to an external drive which I kept at work but now I'm home based I don't have an 'offsite' location to store that backup.

One thing that I really wish camera reviews would look at is the way the cameras name images internally and how they transfer to PC/Mac.
An earlier Fuji camera and my daughter's Kodak both transfer everything on the card every time into a new folder dated when the transfer was made :twisted: - that means you end up with tons of duplicates unless you are very scrupulous about clearing the camera each time which risks accidentally deleting something not saved across or cleaning up after the program which is a pain.

Anyway - if you use a digital camera make copies and backups of your pictures and put the most precious ones on line. A couple of my friends have lost hard drives and seen years of memories disappear in a blink of an eye. One lost all his daughters baby pictures until she was 5 bar a handful he'd emailed to friends or printed out. Horrible!

[edit] that's probably too much information [/edit]

 

[Flyfisher]

I do much the same sort of thing and I also use Photobox for printing, having long since given up with photographic inkjet printers at home.

One package I have found quite useful is Picasa. It's a free application from Google and it has a very effective facial recognition feature. It can catalogue all your photos and will prompt you to enter a name for any face it can't identify. When you enter a name for a face, it will then use that name for all instances of that face it can find. I was quite surprised how accurate it was - even when identifying FF junior from a very young age to the present. Although it takes a bit of time to input all the names for the intial cataloguing, it quickly becomes almost fully automatic and is certainly much, much quicker than manually tagging every photo.

And, yes, you can't have too many backup copies! One thing you should rely on is that storage media WILL fail, eventually.

 

[AMc]

I worked out the per print cost of 6x4 images done with a deskjet, and the time involved and the wastage - IIRC printing about 10 photos could take all day where as I can upload 50 to photobox without paying attention order the prints and often as not have them on the mat the following morning. I junked the printer and bought a little black and white laser - It prints maps and letters in seconds and has run for years on a single toner cartridge.

Picasa interests me but I'm still wary of taking my JPGE image files and locking them into any proprietary system even just for indexing.

I was suggesting with someone the other day that Google's pursuit of putting our data into the cloud and facial recognition could eventually help with genealogical research. We have a number of very old family photos but no indication of who everyone is. There is a remarkable resemblance between my Dad, his Dad and in turn his Dad. It's only a short jump from the Google image search working on keywords to it working on "looks like"...