Search results for 'uv filter' - page 307
Sodium Street lighting - Filter?
I used tungsten-to-daylight filters with film regularly and the results seemed far more predictable and satisfactory than setting the white balance to tungsten with digital. Sadly, I've lost my 80A filters so can't make a direct comparison now. The downside with filters is the loss of the couple of ...
Posted by Aero on 03/01/2010 - 02:11
Sodium Street lighting - Filter?
I just found this ... Sodium light is, or seems to be, more of a colour cast than a colour temperature. I shall give it a go :)
Posted by Smeggypants on 03/01/2010 - 02:27
Sodium Street lighting - Filter?
I believe a correction filter change the temperature of the sodium light to daylight so it won't block that colour but I can be wrong with that. Well it has no use on digital because it always capture red, green & blue and the white balance simply change the balance between the three colours. A ...
Posted by Anvh on 03/01/2010 - 11:01
Sodium Street lighting - Filter?
The problem is that Sodium discharge lamps don't produce a spectrum which looks even remotely like a 'white hot' body. Hence the 'colour temperature' doesn't really exist. The spectrum is not continuous so Sodium light (even high pressure versions) will never give the true colour of some objects bec...
Posted by sophiecentaur on 03/01/2010 - 18:40
Sodium Street lighting - Filter?
The problem is that Sodium discharge lamps don't produce a spectrum which looks even remotely like a 'white hot' body. Hence the 'colour temperature' doesn't really exist. The spectrum is not continuous so Sodium light (even high pressure versions) will never give the true colour of some objects bec...
Posted by Smeggypants on 05/01/2010 - 00:12
Sodium Street lighting - Filter?
Looks like we need a mod :!::!::!::!::!:
Posted by davex on 08/01/2010 - 06:57
Sodium Street lighting - Filter?
Looks like we need a mod :!::!::!::!::!: Yes - the same 'spam' is appearing on other posts :roll:
Posted by Hyram on 08/01/2010 - 07:31
Sodium Street lighting - Filter?
Sorted.....
Posted by johnriley on 08/01/2010 - 08:23
Sodium Street lighting - Filter?
Indeed I'm not loking for accuracy but something that looks nice without the nasty orange cast. As Stefan says, the light from a low pressure sodium lamp is not a continuous spectrum. It consists primarily of two closely spaced yellow spectral lines. These lamps are often used in physics labs, as ...
Posted by andrewk on 08/01/2010 - 15:17
Sodium Street lighting - Filter?
Indeed I'm not loking for accuracy but something that looks nice without the nasty orange cast. As Stefan says, the light from a low pressure sodium lamp is not a continuous spectrum. It consists primarily of two closely spaced yellow spectral lines. These lamps are often used in physics labs, as ...
Posted by Smeggypants on 09/01/2010 - 00:50
Sodium Street lighting - Filter?
Who not so fast :D Indeed I'm not loking for accuracy but something that looks nice without the nasty orange cast. As Stefan says, the light from a low pressure sodium lamp is not a continuous spectrum. It consists primarily of two closely spaced yellow spectral lines. These lamps are often use...
Posted by Anvh on 09/01/2010 - 15:18
Sodium Street lighting - Filter?
I can see what you're saying :) but Sophiecentaur's post here also made some sense .... The problem is that Sodium discharge lamps don't produce a spectrum which looks even remotely like a 'white hot' body. Hence the 'colour temperature' doesn't really exist. The spectrum is not continuous so ...
Posted by Smeggypants on 10/01/2010 - 02:17
Sodium Street lighting - Filter?
yes it does and it is correct but light is difficult to understand. I can see where you're coming from since it's such a narrow band but in what way does the light source differ from each other? Al you try to do with white balance is trying to make white, white and that's exactly what you want r...
Posted by Anvh on 10/01/2010 - 12:46
Sodium Street lighting - Filter?
Looking back to the original thought, which I think was that the OP did not like the appearance of sodium lighting, but did like the alternatives that are sometimes used. Soium lighting is used as I understand it because it's relatively unobtrusive and encourages the eyes to open (good for night ...
Posted by johnriley on 10/01/2010 - 12:58
Sodium Street lighting - Filter?
John I've also heard about the blue lights, it appear that our eyes are pretty good with blue light and keep us awake, our biological clock runs on blue light. Also animals, namely birds, have less of a problem with the blue light. Sometimes they get lost with the yellow lights of the street lam...
Posted by Anvh on 10/01/2010 - 13:14
Sodium Street lighting - Filter?
Sodium lighting is used as I understand it because it's relatively unobtrusive and encourages the eyes to open (good for night driving) and not to close down. The main reason why low pressure sodium lamps are used for street lighting is because it is the most efficient light source - i.e. you get mo...
Posted by andrewk on 10/01/2010 - 19:18
Duplicate finder?
I think Picasa has a 'find duplicates' filter on it. I haven't used it for a little while but that does sound familier. You're braver than me if you use some automated solution to delete images of duplicates though :shock: - make sure you have a backup just in case ...
Posted by woodworm on 10/01/2010 - 19:37
Anyone here keep their 6MP SLRs for infrared?
Wonderful photos Jon, you can probably refurbished the camera to make it more sensitive and of course polish the lens coating away of your lens :D But if you do you won't be able to use the camera 'normally'.:wink: Nice pics, I like #2 for the feeling ofdepth and desolation. This is somethin...
Posted by Hardgravity on 10/01/2010 - 08:30
Anyone here keep their 6MP SLRs for infrared?
Indeed HG, but if your serious in it then it might be worth it. :D I wonder if you can remove the RGB filter of the sensor without much problems and what the algorithm would make of it... With an IR filter you don't capture blue and green so no need to have a filter on that so with IR you will h...
Posted by Anvh on 10/01/2010 - 12:11
Anyone here keep their 6MP SLRs for infrared?
Hi Stefan - yes you can get the camera converted (costs more than the camera though!) and you have the advantave of being able to used handheld shutter speeds. Lens coatings don't help - it's a filter on the sensor that stops cameras from being able to do fast IR shots, and that needs to be removed...
Posted by JonSchick on 10/01/2010 - 12:13
