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GrafiLite desktop colour-accurate viewing light

PostPosted: Tue Mar 24, 2009 1:39 pm
by Potoroo
Has anyone used one of these?

Image

Re: GrafiLite desktop colour-accurate viewing light

PostPosted: Tue Mar 24, 2009 2:56 pm
by Murray Foote
It's going to cost about $185 imported. There have been quite a few colour management products that did not work as well as the claims. This may be really good but I'm a bit suspicious that there is no detailed spectral information on the web site, especially seeing it has a fluoro bulb.

I've been thinking about Solux lamps. You can get the bulbs from Image Science in Melbourne but the lamps are not generally available in Australia (In Oz, MR16 bulbs are for downlights, not lamps). I just tried and couldn't find any in Canberra (though one of the firms is going to look around for me). You can get them on EBay from the US but the freight charges are prohibitive.

Another question - Anyone know how to find a desk lamp that will take a 35W halogen bulb with an MR16 fitting?

Regards,
Murray

Re: GrafiLite desktop colour-accurate viewing light

PostPosted: Tue Mar 24, 2009 3:04 pm
by Murray Foote
Murray Foote wrote:Another question - Anyone know how to find a desk lamp that will take a 35W halogen bulb with an MR16 fitting?

Ah, I think I may have found the answer in another part of the Image Science site. (Haven't chased it up yet, through).

Re: GrafiLite desktop colour-accurate viewing light

PostPosted: Tue Mar 24, 2009 4:50 pm
by Murray Foote
Murray Foote wrote:
Murray Foote wrote:Another question - Anyone know how to find a desk lamp that will take a 35W halogen bulb with an MR16 fitting?

Ah, I think I may have found the answer in another part of the Image Science site. (Haven't chased it up yet, through).

Further update - Ikea no longer stock that lamp and offer no alternatives. Anyone know of a source (perhaps a company that imports from the US)?

Regards,
Murray

Re: GrafiLite desktop colour-accurate viewing light

PostPosted: Wed Mar 25, 2009 9:59 pm
by christiand
Hi,

it may be worthwhile to go to a sewing, quilting or art and craft shop or so.
Some of them have "daylight" lamps.
I bought a 9W daylight some years ago - forgot how much.
It gives neutral light and looks very similar to the one that you have displayed.

HTH,
CD

Re: GrafiLite desktop colour-accurate viewing light

PostPosted: Wed Mar 25, 2009 10:31 pm
by Murray Foote
Hi Christian

I have a daylight lamp, by virtue of putting a "daylight" fluoro bulb into an ordinary lamp. I presume what you are referring to is the same sort of thing.

The problem I have with that is that the colour temperature of the bulb is one thing, but for optimal photographic use you should have one that has a continuous spectrum and not one with lots of spikes and variations, whatever the average may be. I don't know how much difference it will make but I would prefer to follow best practice, if reasonably economic. A discontinuous bulb could potentially be inaccurate for particular colours and perhaps densities. Solux apears to have the reputation. I think for any alternative it would be desirable to see a graph of coverage over the spectrum. I have read that some bulbs deliberately do not provide these because they do not fare well in them.

Regards,
Murray

Re: GrafiLite desktop colour-accurate viewing light

PostPosted: Wed Mar 25, 2009 11:43 pm
by christiand
Thanks Murray,

of course there is a hughe difference in viewing colours with the naked eye using flouro light sources and taking fotos.
I didn't think of it when I posted.
I noticed that the shutter speed (particularly high shutter speed) whilst taking a foto using a flouro light source may shift neutral light into a green tinge and so on.
Neutral (daylight) light - 6000Kelvin ? for doing fotography may require a different light source than flouro.
Perhaps a mercury lamp ? (mercury lamp for aquatic fish tanks ?)
Look, I'm really guessing here - I have had no expreiece with fast shutter speeds in flouro or mercury conditions that much.
However having a certificate and experience in reproduction fotography reminds me that there are even neutral (daylight, 6000Kelvin) flouro tubes (standard length and size to fit in a standart flouro housing) available.
We used them back then (at least a century ago) when we were colour proofing colour seperated films for colour printing in a speciasl contraption that projected cyan, magenta and yellow "films" onto a single pane and thus gave us a colour image of the "end" result.
The light source had to be neutral (daylight, 6000Kelvin) or else the image would have had a unwanted and misleadinding tinge (hue ?).

HTH,
CD

Re: GrafiLite desktop colour-accurate viewing light

PostPosted: Thu Mar 26, 2009 12:44 am
by Murray Foote
Hi Christian

The monitor profiling standard is 6500K but the viewing standard is 5000K. I used to think the viewing standard was an American thing but I now think it's a standard. For example, I have an XRite Pulse Printer/Paper profiling system. When I first got it I tried profilng to 6500K but quickly realised that only 5000K looks right.

This is usefully covered in a review of a viewing box from Northlight Images that I found earlier today. This is a very expensive unit and it uses fluoros so fluoros must potentially be OK. Mine is probably closer to his example of a not-so-good fluoro, though. When I bought it (and it didn't cost much) I asked for a spectral distribution and they couldn't supply one.

Ah, I just found he has a review of the Graflite originally mentioned at the top of this thread. He finds it has a colour temperature of 5600K which doesn't sound very accurate. I can't find anywhere that says what size it is and by the illustration it suspect it may be quite small. If so, it's probably suitable for proofing A4 only and you'd probably need the double one to proof A3+. I also suspect that it may be no better than putting a 5000K fluoro bulb in an ordinary desk lamp (such as i currently have - though I'll have to check whether that one is really 5000K).

Taking another cue from that review, I'll have to download XRite share and see whether it works with my XRite Pulse spectro. I suspect not since it doesn't explicitly have an ambient light mode but I might just be lucky. If it does I'll be able to measure the performance of my light.

Colour separations. You're one up on me on that. An artist approached me a long time ago to do some colour separations for her (involving four colours including black). I read through the detailed instructions and then said "No, thank you".

Which reminds me - I must get back again and try the three exposures with R B & G for multicoloured moving areas. In the old days that used to be three exposures on the same piece of film. These days you could take three different exposures and then combine layers from them in Photoshop. Neutral colour would be easy by including a grey card in an area you could crop out.

Regards,
Murray

Re: GrafiLite desktop colour-accurate viewing light

PostPosted: Thu Mar 26, 2009 1:47 am
by Murray Foote
Interim update -

I found that Keith Cooper also has a review of Eye-One Share as part of his review of the now-discontinued Eye-One design. He tests a "desk lamp with a blue 'Daylight craft bulb'" and finds "poor CRI" (poor representation of all colours) and "spectral response not even warranting a colour temperature".

Regards,
Murray

Re: GrafiLite desktop colour-accurate viewing light

PostPosted: Thu Mar 26, 2009 2:58 pm
by MATT
Try something like this next time you change your fluro light .

This model is a 5300k lamp. Standard 18w fluro, pretty sure they make a 36w one also

http://www.lighting.philips.com.au/au/e ... =technical

I'm pretty sure Phillips make a daylight 5000k lamp also.

Just need to change them every 12months or they colour shift and lose brightness.

MATT

Re: GrafiLite desktop colour-accurate viewing light

PostPosted: Thu Mar 26, 2009 7:30 pm
by Murray Foote
Thanks for that, Matt. The link you pasted doesn't work properly directly for me, it just went to the Philips site. I had to copy shortcut and then paste it into the IE address bar. The Philips site doesn't show a spectral distribution for it but it does show it as having a colour rendering index (CRI) of 98, so it must be pretty good since that is out of 100. I may replace the bulb in my old darkroom with one of those in due course. The one I'm using in my desklamp, though, only has a CRI of 80, so I can do better.

As it happens, I found a clamp-on lamp with an MR16 bulb for $69 (at Southside lighting, Fyshwick ACT). It comes as max 20w but they sold me for $17 an alternative transformer that I can solder in and will take 35w or 50w bulbs. Since I have a bookcase above my computer desk, this is a convenient option for me. The one I got is black, including the inside of the shade, so I won't need the more expensive black-backed Solux bulbs.

Regards,
Murray

(I also found that XRite Share does not work with my XRite Pulse DTP-20 spectro for measuring light.)

Re: GrafiLite desktop colour-accurate viewing light

PostPosted: Tue Mar 31, 2009 9:02 am
by bwhatnall
No matter what the color of the light is, if its in a controlled situation, why not just calibrate with a grey card?

A lot of studios are still using incandescent light bulbs