Lighting - anybody have an experiance of using this sort of thing

[ajohnw]

Just in case anyone else fancies trying PAR38 100w in the same sort of set up I have tried it. Not worth doing but the spotlight types I bought may not be that spot like but given the stray light coming out of them I doubt if it would make any difference..

So over to plan B for a more compact unit when needed.

Having played with them a bit more I think I was being a bit unfair calling them cheap and cheerful. Workman like on a budget is probably more fitting. They come with tri phosphor tubes and unlike some domestic CFL lights don't seem to need leaving on for several mins before they brighten up fully.

John.

[xpatUSA]

Here's a link to an independent test report on the LED 60 degree flood lamps I'm currently using:

http://kronometric.org/phot/xfer/4Ar...0%28015%29.pdf

There is a 40 degree version that gives more lumens (~1200lm), not surprisingly.

The spectral output is well worth checking for it's smoothness and lower blue content. From a luminosity viewpoint, the variation in amplitude is even lower because the graph is in radiometric units.

[ajohnw]

Plan B



Still life continuous lighting reflectors. They are available to fit the edison screw bulb holders. The light levels look to be similar to the silver brolley and the pool of illumination is still on the large side but considering the cost against something better I can't complain and the reduction in size over the brolley is useful. My son has already found there are no colour balance problems

Lots more light than comes out of a 100w PAR38 bulb Ted.

John
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[xpatUSA]

Plan B




Still life continuous lighting reflectors. They are available to fit the edison screw bulb holders. The light levels look to be similar to the silver brolley and the pool of illumination is still on the large side but considering the cost against something better I can't complain and the reduction in size over the brolley is useful. My son has already found there are no colour balance problems

Lots more light than comes out of a 100w PAR38 bulb Ted.

John
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Interesting. Do you have a light meter? My 970 lumen 60 deg LED lamps give about 1030 lux at 1 meter. The 40 deg model is 1210 lumens.

My smaller CFLs with reflectors like yours give 220 lx at the same distance, so I got a good improvement too.

Wasn't sure what 100W PAR38 lamp you tried, but I found a 90W halogen that gives out 1310 lumens at a beam spread of 30 degs:

http://www.satco.com/s4675.html

No pics today. Computer is down

[ajohnw]

I think I can measure it with my colorimeter, probably in lux. I'll have a look tomorrow. Her inside calls.

John
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[ajohnw]

Interesting. The CFL comes out at 321 lux. The PAR38 comes out at 338 with the still life reflector on and 321 without. All measured at 1m.

From looking at the light visually I find that hard to believe and wonder if it's down to the measuring angle of my colorimeter. The CFL light is far more even and from about 1.5m can easily light up a 1m square table with over spill. The PAR 38 can also but more over spill and less even lighting. The bulb is very similar to the one in the link. They all seem to be the same in this respect where ever they come from - dimples all over the place.

In comparison my normal light levels read 38 Lux.

John
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[chauncey]

I gotta say that you guys are getting way too complicated for me...I simply use 3-4 Home Depot
LED shop lights with dimmers attached for all my pre-darkened, studio, tethered shooting.

Lighting adjustments are made based on that image displayed on my monitor and all WB color
alterations are integrated with my X-Rite Passbook. The KISS method seems to work for me.

[ajohnw]

I gotta say that you guys are getting way too complicated for me...I simply use 3-4 Home Depot
LED shop lights with dimmers attached for all my pre-darkened, studio, tethered shooting.

Lighting adjustments are made based on that image displayed on my monitor and all WB color
alterations are integrated with my X-Rite Passbook. The KISS method seems to work for me.

That sure does sound simple WM but I suppose you can't afford the stands so have to make do

John
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[Inkanyezi]

I'd say chauncey's approach is reasonable and productive.

It all comes down to what the things actually do in practice. There is no reason to ask for a smooth spectral curve, when neither the best light we have, natural daylight, nor our very eyes or camera sensors are smooth in response. For a very long time, lighting engineers have known this, and the practical outcome is the tri-colour FL tubes and similar LED fluorescent light sources that are more and more common.

The high blue-violet spike, and the dip at about 480 to 490 that Intertek measured are typical for what fluorescent light sources will display, and the major problem with fluorescent sources - including LED - is that their electroluminiscens lacks red, as red is unsuitable for fluorescing. So a red phosphor is needed, and in the measured lamp, it creates a huge hump that is rather smooth in the red region.

But we do not need a smooth curve. We can adjust our output to near tri-stimuli metameric match, as long as there's sufficient of the important wavelengths in it. We use only three colours, and our lamps need a decent mix of those three colours. Some other wavelengths also stimulate our receptors, as well as the camera's, but it is not very different from cooking. A good cook makes food taste well, and good lighting technicians can provide very pleasing lamps.

After all, our visual art is an art, and the light is our palette, in combination with the Bayer pattern and raw conversion software, as well as our presentation media, on paper or screen. Most lamps with 80+ or better Ra value (CRI) will work fine for photography.

My preferred lamp for small sets is a LED clamp fixture, LOKE, sold by Clas Ohlson. http://www.clasohlson.com/se/LED-spo...ke/Pr364871000

I also have a few other lamps, most of them 2700 K LED.

There is no great difference in colour between 80+ and 90+ lamps after we have converted the raw file, but there is a huge difference between lamps 5000 K and above, when compared to under 5000 K. Those under 5000 K include incandescent bulbs, and those indeed have a very smooth spectral curve. But smoothness of the spectral curve is a moot point. It is mainly the mix of three colours that comprise the light we use for seeing and for photography. There is a huge difference in rendition with incandescent, that truly has a smooth curve, and daylight, which doesn't. We often prefer the daylight rendition, and the smooth curve of the incandescent lamps may be altered by a neodymium oxide filter to mimic the non-smooth daylight curve.

So, all the lamps reported here work for photography, and the only thing to keep in mind is that mixing different lamps may wreak havoc with colours - when it matters.

[chauncey]

mixing different lamps may wreak havoc with colours

That's the vary reason that I pull the drapes and darken the room...remove that window light.

[xpatUSA]

That's the [very] reason that I pull the drapes and darken the room...remove that window light.

Personally, I don't bother. In my camper 'studio' there are are no drapes but the windows are small and the camper is surrounded by very tall trees and woodland. At the bench I also have a small Philips TL950 overhead fluorescent tube which is always on. However, my LED floods provide much more illumination at the subject than either of those other sources of light to the extent that I ignore them, insofar as correct WB is concerned. (I only shoot raw).

What I am saying here is that the dreaded "mixed lighting" with all it's doom and gloom can quite be insignificant under some lighting conditions.

[ajohnw]

The Ikea lamps I sometimes use are very similar in spec to the ones you link to Urban except they are 3w and 2700K.

The lamps I started the thread with following measuring their colour temperature and luminosity values turn out to be just under 5000K and have a delta e as far as the colorimeter is concerned of 4, better than many typical off the shelf monitors. When light is recorded via filters in principle all that is needed is 3 spikes of the correct colour and magnitude so in some respects smoothness doesn't matter. All that does matter is the levels in the region a camera responds too so conventional thinking about lighting in rooms etc goes to the wall.

In terms of photographing small things there are other approaches that don't assume that the lights have to be small, diffusers for instance. I have just taken one with the lamp around 150mm from the pen nib with the still life head on. The brolley would be a problem. The biggest problem is the camera used and probably that the pen nib needs cleaning. For interest only I will stick it on the end of the macro thread.

John
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[Inkanyezi]

Of course lamps can be larger also when shooting small things, but a small lamp can often be brought closer and it might be easier to work with for various reasons. Mostly I shoot just anything using window light, but this time of year, there's not a lot of it. So it boils down to using what is practical. When I have only a small area to illuminate, a small source can be sufficient. This little Loke lamp is actually a soft light when close. I also have other LED lamps with a large panel, which is like a softbox when at a distance of only a couple of inches or so. Horses for courses.

So when my subject is a tiny screw or something of similar size, a small lamp won't spill a lot where I don't need it, and even a lamp with only a couple of watts is a powerful source, when only a few square inches have to be lit. Of course they are pretty useless for taking portraits of people.

[EricRich]

Light bulbs seems good but don't have any practical experience with these. Fresnel lights are good lights. The Camtree sun Fresnel lights are bright lights and perfect lights for studio photography. These are soft lights and dimmer control is perfect. These lights are really awesome, especially for highlighting your subject and illuminating their face, allowing them to stand out from the background a whole lot better. They are perfect as an indoor solution for photography or video where your subject is very close I bought these lights online from thecinecity.

[xpatUSA]

Light bulbs seems good but don't have any practical experience with these. Fresnel lights are good lights. The Camtree sun Fresnel lights are bright lights and perfect lights for studio photography.

They look very good and the adjustable beam helps, as does the lighting power which puts my LEDs to shame!