LED lights for shooting artwork

Discussion in 'Lighting Equipment' started by lynnherring, Dec 3, 2017.

  1. Hi, I'm new to photo.net. I am an artist shooting my work and I have a Nikon D3400. Years ago I bought a CFL light kit with softboxes. The lights are pretty awful so a professional photographer friend told me to get 4 work lights at home depot using incandescent flood lights. I did that and for small/flat work, it was fine. I have a larger piece 36" square and 3" deep. I layed it on the floor on white seamless and set up the work lights. There were shadows going in all sorts of directions so I got out the CFL light and the softboxes. There wasn't enough light to shoot at the f stop I need without using a desirable ISO. Would LED floods work in these softboxes or do I need to invest in a better lighting kit? My funds are limited and would prefer to keep from spending a lot of money. Any ideas? Thanks in advance!
     
  2. "There wasn't enough light to shoot at the f stop I need without using a desirable ISO."

    - A 3ft artwork is actually quite small, and you should be able to light it easily.

    - I presume your artwork doesn't move? So if your camera won't allow a long enough shutter speed to use the CFL lights at any desired aperture, you need a better camera. And if you're trying to handhold the camera, buy a tripod! Or rig up something else to hold the camera steady parallel to the artwork.


    No affordable LED panel is going to improve on the light output of CFL lights.
     
  3. The camera is fine. I wanted a lower ISO so there would be less grain. So, maybe I need to find another setting. It's a new camera and I'm trying to get used to it.
    The CFL lights are not very bright. I do have a tripod. I think I might need to rig something up and get on top of the work somehow.
    Thanks for your quick response.
     
  4. Since you're on a budget I'ld suggest the 5000K Hyperikon's BR40 LED diffused flood-Model: HYPERBR40-502. CRI rated at 94 but a bit saturated in the yellows. 1360 lumens. I'm using one as a print viewing light. The image below is one lighting my digital photography workstation and represents pretty close to how they render color and white balance.

    I metered the brightest part of the wall at 1/30's, f/8, ISO 200 with the light two feet away. As you can see they produce a very broadly diffused glow. With Amazon Prime they cost me around $10 each. 4 of them ought to be enough to light large pieces of art.

    Just a caveat, I bought a second 5000K and it's white balance was slightly greenish yellow, close to a buttermilk tint. The Hyperikon company is sending me a replacement free of charge. They have 5 year unlimited warranty.

    _017805HprikonCCchart.jpg
     
    Last edited: Dec 3, 2017
  5. Thank you Tim! I'm going to try this!
     
  6. If you are gonna be critical about the color quality, your photographer friend told you right. Neither CFL nor current LED technology has the spectral "quality" of a "quartz-halogen" lamp, which is what I presume your worklights are. (They will have a different "color" compared to daylight, but the "white balance" of your camera should be able to correct for this.)

    Per Tim, the light he suggests has a CRI = 94 ("ideal" is 100, which is roughly what any daylight source is). Your tungsten-halogen work lights will be CRI about 100, possibly as low as 98 or 99. As long as our main light source continues to be the sun, it will be hard to beat the spectral quality of your work lights.

    To be clear, they have an overall different color than sunlight or daylight - they are much more yellowish, but either your camera's white balance setting OR filters can match the effect to that of sunlight. This CANNOT be done, to a critical level, with those other two lamps.

    Personally, I'd prefer to use electronic flash, which for all practical purposes is as good as daylight, but it's much more expensive. If I were in your shoes, I'd be trying to deal with the shadows from your work lights. A good place to start might be to "bounce" the light off a piece of white poster board - this makes a larger light source (for "softer" shadows). I would only consider those other two lights if you are not super finicky about the color, or you know that the specific colors you use are ok under those lamps.
     
    jan_steinman likes this.
  7. To expand on my caveat about slightly different white balances between the same bulb model/brand is that for large artwork where there is large areas or borders of white canvas or illustration board, you're going to have a tough time correcting such tint differences unless you make all substrate go to 255RGB which may require masking or selective color. I recommend shooting Raw.

    Below is what the Hyperikons look like where the two bottom ones are the 5000K (note tint difference) and the top one is 4000K. Light fall off will also change the tint depending on distance from subject the more bluish neutral where short wave of the blue pigment will render more yellow. This is typical of most of the CFL/LED non-tungsten lights meant for home use I've bought in the past.

    I'm expecting to get the Hyperikon replacement tomorrow and see if the tint matches the first one.

    Since Bill C mentioned flash you might consider getting two speedlights, one on each side of the artwork, or if you run into white balance mismatches use one with a white board bounce fill on the opposite side.

    _01IMGP7857.jpg
     
  8. Just got the Hyperikon 5000K replacement and it looks like they changed the white balance diffuser dome filtering design (see image below of the transparency differences) to favor a more buttermilk yellowish hue. Two of them together put out a lot of light and match in white balance hue.

    _01yeloHyperIMGP7996.jpg
     
  9. If color reproduction is important then you really need to use strobes, speedlights or color balanced cine lights. The following (hopefully OK to post since it's not an artistic photo) will give you an idea of how a 92 CRI LED looks compared to other sources, including CFL. 94 CRI will be better but only slightly. Also, each manufacturers LED and even different ones from the same manufacturer will produce different spectrums. Keep in mind that CRI is actually a poor measurement. A 94 CRI that just happens to do well on the test swatches may not provide as good of reproduction as an 88 CRI that is overall better but misses a bit on one swatch.

    [​IMG]
    Image: Ultimate Light Bulb Test - Incandescent vs. Compact Fluorescent vs. LED
     
  10. I mostly agree, except that any incandescent bulb can be filtered to do just as well (OR, compensated by a digital camera white balance). The problem with "normal" incandescent lamps is that bluish energy is very low - ideally they should be operated at higher temperatures. Only the quartz halogen versions can do this sensibly (otherwise bulb life is short).

    This is why I suggest to keep using the work lights (for economy), but find a way to get the shadows under control.
     
  11. This is getting far too technical and over complicated.

    I still not sure why you can't simply use a longer shutter speed with your existing camera and CFL lamps. The ISO setting is irrelevant if the camera can compensate by setting a longer shutter speed.

    Your CFL lamps should easily provide enough light for something like 1/15th second at f/8 and 100 ISO. So even if you stop down to f/22, you still only need half-a-second exposure time. I don't see a problem? Unless the camera is incapable of providing long exposure times. In which case it's probably not good enough for high quality reproduction work.

    Tim, those Hyperikon LEDs only have the equivalent output of a 100 watt tungsten lamp. How would they improve on the brightness of a photo quality CFL?
     
    Last edited: Dec 5, 2017
  12. Yes, agree completely.

    If the color and light output from the work lights is acceptable then maybe stick them behind a couple of 4' scrims or other diffusor or bounce them off pure white walls or ?? For that matter, there's a great light source outside most days. A bit of diffuser and presto! :)
     
  13. I don't think there IS such a thing.

    CFLs were originally made as "energy saving" replacements for conventional bulbs, and in this vein have been mostly, if not all, as energy efficient versions of fluorescent lamps. This style always has the very spiky spectral graph, similar to what WAngell shows, and is not much good when good color reproduction is needed.

    If someone wanted to manufacture a CFL with good color reproduction, it would be visually much dimmer than the energy-efficient version, and would most likely not sell very well. So I doubt that it will happen.
     
  14. Your proposed exposure parameters using a tripod for the OP's camera and existing photo CFL's don't really reduce noise regardless of ISO setting which is the point made by the OP. I know why he's getting noise using CFL's from all the handheld shots I've made at my camera's base ISO 200. Four Hyperikons setup on each corner of the artwork at 45 degrees will pretty much provide a broader dispersion of light for artwork 36 inches on the long side as well as make it easier to adjust positions. I think my last image shows the dispersion quality of the light which is needed for large artwork.

    I'm not a spokesperson for Hyperikon. I'm only saying what I'm seeing compared to all the other daylight LED's and CFL's I've bought in the past. All of them produce some level of noise depending how close they are to the subject no matter the ISO setting. If noise is what is not wanted, low light isn't the solution.

    This is why I agreed with Bill C that a flash setup is best, but can require extra cost in setting up for even illumination of artwork of this size.
     
    Last edited: Dec 5, 2017
  15. Here's a handheld Raw shot showing noise in the shadows at my base ISO 200...53mm, 1/125's, f/7.1, with my hand within a foot from the Hyperikon 4000K. Flash usually doesn't produce this level of noise.

    Screen shot 2017-12-05 at 5.05.20 PM.png
     
  16. There are two issues here as I see it:

    1) The OP has lights that are plenty bright enough, but are hard sources that produce multiple shadows on the artwork.
    2) The OP also has diffused lights, which (for some as yet undetermined reason) are deemed not bright enough.

    The solutions:
    1) Diffuse the brighter worklights in some way.
    2) Brighten the CFL lamps. I've seen photo-quality CFL tubes of around 200 watts - equivalent to 1Kw of tungsten.
    3) Work with the existing CFLs and simply lengthen the exposure time. Exposure is exposure, and the same amount of light hits the film/sensor whether it's 1/1000th sec @ f/2, or 1/8th sec @ f/22.

    Replacing the hard worklights with equally hard, and probably dimmer, LED bulbs isn't a solution.

    Nowhere has the OP complained of poor colour rendering using CFLs, although ideally a more continuous source might be needed. But for now we have no more details of the artwork other than it being 3 foot square and 3" deep. It might be painted white for all we know.

    Conclusions are being jumped to about the OP's requirements that are totally unsupported by the information we've been given so far.
     
    Last edited: Dec 6, 2017
    GerrySiegel and Charles_Webster like this.
  17. The information whether supported or not supported by the OP's requirements is useful for anyone interested enough to read to help formulate questions to ask in order to avoid the caveats of shooting artwork.

    IOW everyone's input in this thread has not been a total waste of time.
     
  18. I'd be interested in a reference or explanation of how you determined "photo-quality."

    I've done considerable searching, including purchase of a handful of systems off the internet, including from a well known photo supply house. I test shot portraits, and none of these systems matched the color "quality" of studio flash. At least not within the quality standards of a mass market portrait chain. The evaluation was based on prints, hand balanced to match flesh tones, and viewed in a large color correction booth.

    It's been a half dozen years or so, though; perhaps things have changed.
     
  19. Just an update about my dealings with Hyperikon color temp hue differences within the same model of 5000K. Support service lady through emails indicated the new updated look of 5000K is the one on the right in the posted image below. IOW the greenish buttermilk hue is the current and only version they could find. At least the new version can reasonably render colors correctly by editing for R=G=B on a neutral gray target.

    cc_IMGP8008.jpg
     
  20. OK. If we want to get overly technical and complicate things:

    Common "white" LEDs are basically a solid-state fluorescent lamp. The LED chip emits in the near UV region, and this radiation is converted to visible light by an overlaid fluorescent layer. As such, the spectrum isn't continuous by a long way, having a noticeable gap in the cyan region of its spectrum. That's why LED panels specifically designed for photo/video use usually use a mixture of LEDs to fill in those spectral gaps.

    Another issue is the colour temperature of domestic LEDs. A CT of 4000K demands that any digital camera has its blue channel boosted in order to balance the colour. Effectively, this means the blue ISO sensitivity is raised, and will have sub-optimal noise in that channel. This effect could easily explain why the noise seen from using 4000K LED lamps is greater than that from ~6000K flash lighting.

    Besides, most decent cameras have a long-exposure noise reduction facility that can be turned on to reduce noise in low light conditions.

    I make no claim that CFL lamps are perfect, or even halfway decent in colour rendering. I'm just pointing out that they don't have to be short on brightness. And that if the OP already has softboxes and luminaires designed to take CFL lamps, then fitting higher power tubes is an economical solution.

    The claim of some CFLs being "photo quality" is made by their manufacturers and sellers, not by me.

    I still see no reason for this thread to have been turned into a symposium on colour reproduction. That wasn't what the OP asked for.
     
    Last edited: Dec 10, 2017

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