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Forum: Flashes, Lighting, and Studio
02-20-2019, 02:00 PM
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My Aputure AL-MX light arrived today :) Quite a piece of equipment, very solid, well built and beautifully finished. I'm amazed, given the price.
I hadn't paid much attention to the advertised specifications other than lux and colour temperature ranges, but according to the manufacturer's specifications, it achieves a CRI (Color Rendering Index) score of 95+, and a TLCI (Television Lighting Consistency Index) score of, again, 95+. For a modestly-priced lighting device, I guess those measurements ought to be treated with a at least a little skepticism, Still, given the highly professional build quality and presentation, I'm hopeful that the manufacturer may not have exaggerated too much.
I hope to run some tests over the next couple of days, and intend to report back :)
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Forum: Flashes, Lighting, and Studio
02-20-2019, 04:04 AM
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Your interpretation is correct, Dave. My primary interest here (although the thread has evolved to include other helpul and related elements) is in achieving suitable man-made illumination of a test target so that I can take shots for use in developing custom camera profiles. Relying on natural lighting conditions is patchy at best in this country and requires patience (as well you know :p), especially at this time of the year.
A lighting panel with adjustable colour temperature that can illuminate a target at both 2850k and 6500k (or reasonably close to both) seems like a useful tool, even given the subsequent concerns around spectral spikes from the LEDs. Absolute accuracy isn't something I'm desperately concerned about (though that would be nice, of course). If I can produce dual-illuminant profiles that work nicely with no significant colour shifts in different lighting situations, I'll be more than happy.
I'm awaiting delivery of the panel, and looking forward to trying it out. I'll post a new thread on my findings in the near future, and provide a link here :)
Even on my ColorChecker Passport, I get *tiny* differences in white balance values from white versus mid grey, but in my case they're so tiny as to have no visible effect. Whether this was always the case, or it's as a result of the card being a few years old now, I can't say...
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Forum: Flashes, Lighting, and Studio
02-16-2019, 03:19 PM
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Well, I just bought the Aputure MX LED light panel, for delivery some time in the next week. I figure I have little to lose... I can try it for dual-illuminant colour profile creation, but if those profiles should prove problematic for general use, it'll serve as an alternative for close-range indoor single-flash photography. Given the cost and my non-lab-level requirements, I think it might be a useful piece of kit. Either way, I'll let you good folks know :)
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Forum: Flashes, Lighting, and Studio
02-16-2019, 02:11 PM
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Thanks again, Dave - very useful info. I tend to agree with you that trying to create an "absolutely correct" profile might be folly given all of the variables. Indeed, you mention your colour chart... my own ColorChecker Passport is a few years old by now, so the colours probably aren't 100% accurate on that alone, before lighting issues are taken into account.
And now I'm thinking... Even though there may (will?) be some spikes in the spectrum, that variable temperature light panel I originally mentioned might be "good enough", since I'm not looking for lab-quality colour accuracy but rather a decent starting point in each of my profiles. I can live with minor inaccuracies. Or I could go with the flash + gel approach helpfully suggested by others, which would seem to offer an equally useful, if - once more - not 100% colour accurate option.
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Forum: Flashes, Lighting, and Studio
02-16-2019, 12:18 PM
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Dave - thanks for your efforts here, and for posting the results. Whilst there are certainly differences, they are smaller than I would have expected.
Can I ask, what was the daylight balanced LED light that you used? And how did you go about creating the averaged profile?
I thought I could also see a tiny slight pink / magenta cast in the greys of the flash image when viewed on my older calibrated laptop, but when I look again I don't see it. I haven't yet viewed the images on my newer calibrated laptop and desktop monitor. That said, the sample outdoor image processed with different profiles looks great, and the clouds look completely natural to my eye...
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Forum: Flashes, Lighting, and Studio
02-14-2019, 02:49 PM
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Given the additional issues mentioned...
Does anyone have any idea how Adobe and other major software vendors produce their dual-illuminant profiles? I can't imagine they wait for just the right lighting conditions outdoors. Surely they must use indoor lighting of some sort to photograph the relevant colour charts for profile creation? If that's the case, I really wonder what lighting they use...
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Forum: Flashes, Lighting, and Studio
02-13-2019, 04:54 AM
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Thank you, everyone, for the useful responses and information. Most interesting... I hadn't understood about spikes in the colour spectra with LEDs.
It seems like I might be better served using off-camera flash and gels - and it's a cheaper solution, too, since I already have the flash units :)
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Forum: Flashes, Lighting, and Studio
02-09-2019, 04:47 PM
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So...
I'm wanting to create my own dual illuminant camera profiles for various cameras that I own, and software that I use, via a couple of different software approaches. I've done this before, but always using whatever estimated natural lighting conditions I've had available to me at the time. This worked OK, however... here in the UK, especially at this time of the year, it's very difficult to find natural lighting at 6500 and 2850k.
For some time, I've been thinking that an artifical light source in a darkened room would provide better conditions for the colour chart reference shots I need in creating these profiles.
I've come across a low cost product that I might be interested in, here:
Aputure AL-MX 2800-6500K CRI95+ LED Video Light Lamp for DSLR Camera Camcorder 635946656549 | eBay
This is an LED panel lighting source that allegedly offers stepped adjustment of temperature between 2800 and 6500K.
Given the rather low price, I'm assuming the colour temperatures specified aren't especially accurate, and yet I wonder if they might be good enought to provide illumination that's approximate enough for my intended application?
Alternatively, I'd be interested to know of other options. I could afford to spend more, but would rather not spend a lot more unnecessarily. Then again, I'd rather spend nothing at all if the budget approach is going to be useless...
Thanks in advance for any views, opinions and ideas :)
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