Gretchen, there's a jillion LED lights for photo work that are balanced at 5600 K.  Many are portable and work on batteries.  Here's an example....

https://www.bhphotovideo.com/c/search?atclk=Head+Type_Light+Panels&ci=12248&N=3988592074+3942861147

I don't know how long they last on any certain battery, but these are often used in architectural setups where they may be on for hours. However, you might give BH a call and ask to talk to one of these dudes...

https://www.bhphotovideo.com/c/browse/continuous-lighting/ci/22521/N/3988592086 

Tell them exactly what you want to do and they can probably help.  Ask how long batteries will power the light.  You may need to purchase a light stand .... about $30.  There are over 2000 entries under LED lights at BH, so looking for something on your own could take a while.

Suerte,
bab

On Tue, Oct 17, 2017 at 5:42 PM, mali moir <[log in to unmask]> wrote:
Hi all
I would also like to find a great lamp, for my students as well. 
I have several battery led lamps, none of them are bright enough. 
It's often hard to find details of the lumens in the ads. 
Mali

Sent from my iPhone

On 18 Oct 2017, at 2:25 am, gretchen halpert <[log in to unmask]> wrote:

Hi Folks,

I'm looking for a battery operated lamp to use during workshops that has good color balance. 

Many people use OTT lights. I like them well enough for sketching, but not for watercolor work or direct scientific lighting. I don't like the color the OTT puts out, nor the difficulty getting proper scientific lighting.


Any suggestions? It has to be cordless.

Thanks for your experience.

Gretchen

Gretchen Halpert
Illustrator/educator
Scientific Illustration Distance Program

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