Lighting editing booth - Ott-Lite OK?

[AFairley]

Because my computer is set up next to a large window in a room with colored walls, I made myself a collapseable editing booth out of foam core to block the extranous light (it sits on the desk and is about 4' across 3' deep and 3' high, with a top). I'm going to paint the rear panel and the rear half of the side panels to match 18% gray. Then I think I will need a desk lamp that will provide color-balanced light to bring the ambient light in to booth up to typical viewing levels (I'm told that the proper ambient light level is that where the image on your monitor and a print held up next to it will look the same). The Ott-Lites are readliy avaliable at where I live, would a 13-watt version (equivalent of a 60-watt incandescent bulb) do the job OK?

Any other recommendations for a sub-$40 desk light (I need something that can sit on the front corner of the desktop).

Thanks

[huntz]

Because my computer is set up next to a large window in a room with colored walls, I made myself a collapseable editing booth out of foam core to block the extranous light (it sits on the desk and is about 4' across 3' deep and 3' high, with a top). I'm going to paint the rear panel and the rear half of the side panels to match 18% gray. Then I think I will need a desk lamp that will provide color-balanced light to bring the ambient light in to booth up to typical viewing levels (I'm told that the proper ambient light level is that where the image on your monitor and a print held up next to it will look the same). The Ott-Lites are readliy avaliable at where I live, would a 13-watt version (equivalent of a 60-watt incandescent bulb) do the job OK?

Any other recommendations for a sub-$40 desk light (I need something that can sit on the front corner of the desktop).

Thanks

The Ott-Lite I used gave everything a greenish cast and prints never match my profiled monitor.  Drove me nuts until I figured out it was the light and not the monitor, video card, or profling hardware/software.

[AFairley]

The Ott-Lite I used gave everything a greenish cast and prints never match my profiled monitor. Drove me nuts until I figured out it was the light and not the monitor, video card, or profling hardware/software.

What did you replace it with?

[madmanchan]

I would recommend a 4700 K or 3500 K solux bulb instead.

[digitaldog]

Ott-Lites kind of suck <g>. There's nothing special about them. Solux is far preferable.

[huntz]

What did you replace it with?

I found that what works best for me is to not use a dedicated viewing station at all but to simply view prints in my matting/framing studio, which is lit with Phillips full-spectrum TL950's.

[Bas Stekelenburg]

I found that what works best for me is to not use a dedicated viewing station at all but to simply view prints in my matting/framing studio, which is lit with Phillips full-spectrum TL950's.

I did the same with very good results. But to be more specific on the TL's: TL-D90 GRAPHICA. Mine are 36w/950, there are larger ones too. CI = 98! I made two sets, each with a Philips electronic ballast good for two TL's (HFP236TLD; no more starters and without flickering due to high frequency switching). Under this light I photographed the X-rite Color Checker. In Lightroom I measured for white, left under, 5000 Kelvin, exactly! All other colors where on the calibrated monitor without differences to the X-rite cart.

Bas

[digitaldog]

There really is no such thing as a "full spectrum" Fluorescent thanks to that nasty mercury. And CRI isn't a very useful metric based on who it was designed to make look good (Fluorescent manufacturers).

If I can quote myself <g>

As for CRI, it's a bit of a kludge to make a light source appear to be closer to daylight for marketing and light manufacturers. CRI was developed in large part to aid in the sales of Fluorescent tubes. As you point out, there are tiles used to compare under a reference light source but only eight. That's too small a set of tiles. The manufacturers pick the tiles. That make it easy to create a spectrum that will render the 8 tiles and doesn't tell us that the light source is full spectrum. It doesn't tell us how the other colors will render. My understanding is there are two reference sources; Tungsten for warm bulbs and D50 for cool ones. That means that a normal tungsten bulb and perfect daylight both have a CRI of 100! As such, a high CRI is a decent gauge of how well a light will preform in your home but not such a great indicator of how well it will work for photography and proofing. Both a Solux 48 and a "full spectrum" tube from home depot may have a CRI of 97. I can assure you the Home Depot bulb has a giant mercury spike and some spectral dead spots.

[alain]

Hi

There's more than only the light quality itself.

A nice read :

http://digitaloutput.net/content/ContentCT.asp?P=214

and some info from Just Normlicht, see page 3-4 about some basic info that's also nice to know when making you're own...

http://www.spotlitur.com/images/JUST/just-...otlitur.com.pdf

18% grey seems very dark to me, it's more important to avoid even small pieces of white and glare off course.  Getting even lighting is also not trivial.

 
Digitaldog :  Just Normlicht seems to use a 215 tile CRI also.  I do suspect that most cri>98 TL's use the same technique to get at the 98 and maybe even come from the same factory.  
Do you think that the difference between a TL cri>98 and a solux is visible in an own made viewing booth?  
The solux lamps that I've read about are spots, is it easy to get even light without putting it far from the print?

[digitaldog]

Digitaldog :  Just Normlicht seems to use a 215 tile CRI also.  I do suspect that most cri>98 TL's use the same technique to get at the 98 and maybe even come from the same factory.  
Do you think that the difference between a TL cri>98 and a solux is visible in an own made viewing booth?  
The solux lamps that I've read about are spots, is it easy to get even light without putting it far from the print?

The best test is to measure the spectrum of the light using an EyeOne Pro and EyeOne Share. Pretty obvious which are full spectrum when comparing any Fluorescent to a Solux.

[alain]

The best test is to measure the spectrum of the light using an EyeOne Pro and EyeOne Share. Pretty obvious which are full spectrum when comparing any Fluorescent to a Solux.

I know the measured differences, but the spices are a lot less for the cri 98 versions.

Here for a Philips tl 950 graphica pro (last page)

http://www.prismaecat.lighting.philips.com...18W_950_1SL.pdf

My question is rather if a human can spot the difference.

Alain

[digitaldog]

My question is rather if a human can spot the difference.

A lot depends on the substrate. One of the issues with the spikes is how it affects perception in the presence of OBAs. Often, a magenta appearing cast appears.

[madmanchan]

I also don't recommend any fluorescent-based system for precisely the reasons Andrews stated above, i.e., the strong emission lines in certain parts of the spectra will lead to strong color distortions in some cases.

[digitaldog]

I also don't recommend any fluorescent-based system for precisely the reasons Andrews stated above, i.e., the strong emission lines in certain parts of the spectra will lead to strong color distortions in some cases.

I'd only add that I do use GTI booths for compatibly with other clients who have them. Such booths are common in print shops and the like.

[AFairley]

Thank you all for your comments, this thread has been a real eye opener for me!

[alain]

Hi

Thanks for the info, probably will add a few solux bulbs to my current -self made- viewing booth.

I do see a problem to get it an even lighting, the solux are spots (even at 35°).  Are there examples on the internet for a viewing booth type of setup?
(I don't have much space and the current fluorescent-based system fits nicely to give an rather good even light.)


Alain

[huntz]

For me at least this is one of those areas in photography where "measurebating" is not very useful.  I have to trust my eyes, and  I'm not seeing any significant color casts or "strong color distortions" with the 950's at all.  In fact, I'm getting the most uncanny screen-to-print match I've ever had (NEC/SpectraView/i1).  Also, another thing I like about using my matting/framing space for viewing prints is that it more closely approximates the kind of environment where people typically display my prints--mixed home and office lighting.  To me this is a more "natural" and effective way to judge tonality, etc.

[digitaldog]

For me at least this is one of those areas in photography where "measurebating" is not very useful.  I have to trust my eyes, and  I'm not seeing any significant color casts or "strong color distortions" with the 950's at all.  In fact, I'm getting the most uncanny screen-to-print match I've ever had (NEC/SpectraView/i1).  Also, another thing I like about using my matting/framing space for viewing prints is that it more closely approximates the kind of environment where people typically display my prints--mixed home and office lighting.  To me this is a more "natural" and effective way to judge tonality, etc.

The problem is, your eyes can tell you the illuminant is AOK, only to find that using a differing substrate in the future will result in a color cast due to the lighting and OBAs.

Trusting your eyes is a good thing. But it doesn't mean you will not be burned later. Also, your eyes can't tell you if there's a nasty mercury spike nor how it will affect other materials in the future. At least looking at the spectrum of the light using an instrument can tell you if you're likely to get burned in the future or if indeed, you've truly got a full spectrum light.