JohnBrawley Posted October 1, 2018 Share #21 Posted October 1, 2018 Advertisement (gone after registration) A 4000K ring light says to me that an LED ring light was used ? If that's true, then in my view the light source should be something with a better (flatter) spectral output. LED lights are terrible for skin tone and I'd hate to use that as the test light source for this kind of comparison ? JB Quote Link to post Share on other sites More sharing options...
Advertisement Posted October 1, 2018 Posted October 1, 2018 Hi JohnBrawley, Take a look here Skin tone with S(006), S(007), SL, and X1D. I'm sure you'll find what you were looking for!
mgrayson3 Posted October 1, 2018 Author Share #22 Posted October 1, 2018 A 4000K ring light says to me that an LED ring light was used ? If that's true, then in my view the light source should be something with a better (flatter) spectral output. LED lights are terrible for skin tone and I'd hate to use that as the test light source for this kind of comparison ? JB Wonderful! I eagerly await your results with better lighting. --Matt 1 Quote Link to post Share on other sites More sharing options...
AlanD Posted October 1, 2018 Share #23 Posted October 1, 2018 Wonderful! I eagerly await your results with better lighting. --Matt Quote Link to post Share on other sites More sharing options...
JohnBrawley Posted October 2, 2018 Share #24 Posted October 2, 2018 (edited) Wonderful! I eagerly await your results with better lighting. --Matt Below I point to many tests with more consistent lighting that takes into account the flaws of LED lighting. I routinely do camera (and lens) testing as part of my work as a cinematographer, and I've learned that if you're comparing cameras, then the spectral emission of the light source you're testing under is very critical, especially if you're concerned with skin tone. You were proposing to test the difference of skin tone performance on different sensors weren't you ? You were publicly asking for people to compare your results. Part of doing this publicly is also to put under scrutiny your testing methodologies. I'm simply asking if you've taken that into account. You haven't actually confiemd it's an LED source, I'm just guessing based on your description. If an LED light which is NOT a continuous spectrum light source doesn't emit a certain colour then how will your subject ever reflect that colour of light to enable your sensor to capture it ? The whole premise of your question is to compare colour response. If the light doesn't emit that colour then how are you measuring the colour response ? I'm only trying to point out what I see as a bit of a flaw in your testing methodology. You went to a bit of trouble to do the test, I'm just suggesting that you get rid of LIGHTING as a variable if you don't use an LED based light source. I don't have access to all the cameras you're wanting to compare. Here's some of the types of testing I've done. 4 different cinema cameras blind tested in the same lighting. (Panavision DXL, Arriflex Alexa, Ursa Mini Pro, RED Helium) Camera order is randomised. https://vimeo.com/259566548 Password is Angie Different cameras compared to explore looks. IR and non-IR filter tests Same camera, different lenses blind tested JB Edited October 2, 2018 by JohnBrawley 3 1 Quote Link to post Share on other sites More sharing options...
mgrayson3 Posted October 2, 2018 Author Share #25 Posted October 2, 2018 (edited) John, Thank you for these comparisons! I am motivated only by "too many words, too few examples" on this subject and nothing more. I do not consider the choice of light a flaw in the methodology. Unless we wanted to compare many different lighting conditions, we had to pick one. If that one happens to be difficult, so be it. It's not as if no one uses LED lighting. (I don't, but then I rarely shoot people.) And showing performance in less than ideal conditions is useful in its own right. After doing some research, I see that, while most tunable LED lights still have a spike in the blue part of the spectrum, they are much smoother than simple RGB arrays. I'll try to get specs on the actual light used. --Matt Edited October 2, 2018 by mgrayson3 Quote Link to post Share on other sites More sharing options...
mgrayson3 Posted October 2, 2018 Author Share #26 Posted October 2, 2018 The light was a Smith-Victor variable temp LED with a claimed CRI of 95. That's a nice number, but if we could rely on specs, none of this would be necessary. --Matt Quote Link to post Share on other sites More sharing options...
JohnBrawley Posted October 3, 2018 Share #27 Posted October 3, 2018 (edited) Advertisement (gone after registration) The light was a Smith-Victor variable temp LED with a claimed CRI of 95. That's a nice number, but if we could rely on specs, none of this would be necessary. --Matt Hi Matt. Most LED's are at BEST 95 CRI and that number is kind of misleading. Many now use the TLCI In truth, no LED is good for evenness in Spectrum. They are often GOOD ENOUGH for what most people need, but it's easy to see their shortfalls when you compare them to other light sources. I find it hard to go past good old Tungsten light. The kind that get's hot and burns your hands. It has a very flat spectral emission. I generally spend time with a good colour temperature meter (sekonic C700) that works with LED lights and use small gell corrections to get it to both 3200K and 5600K so that I hit a known white point that I've shot many times. Some colour temp meters like the older minoltas (now Kenko) don't read LED's properly. The Academy (that do the Oscars) did a big investigation of LED lights recently. you can learn a lot here. https://www.oscars.org/science-technology/sci-tech-projects/solid-state-lighting-project I found this one to be especially relevant. Look at how much her skin tone changes under different lights. JB Edited October 3, 2018 by JohnBrawley Quote Link to post Share on other sites More sharing options...
Guest Posted October 11, 2018 Share #28 Posted October 11, 2018 On 9/23/2018 at 2:52 AM, frame-it said: i like the X1d/phocus colors. +1 Hasselblad colours are 10 times better than what I used to think Leica colours are...........I love the colours I get from my Leica S007, but I guess I love the colours more from what I get with my Hasselblad camera. Now when I converted my Leica S files to B&W they are amazing, better than my old CCB Monochrom and as good as I can get from my Hassy.........strange Neil Another consideration is that we are looking at the pictures of a very pretty model that we have never seen in the flesh......only the person that took the pictures can say whether the files represent the correct skin towns or not, for all we know she could be anaemic with very pail skin, or someone who has been lying on the beach all day Neil Quote Link to post Share on other sites More sharing options...
albertknappmd Posted October 15, 2018 Share #29 Posted October 15, 2018 Nice work and in the end run, I do not see much difference... Furthermore, since everyone is going to modify their pictures in LR and PS, what difference does the initial result really make? 😥😋😎 1 Quote Link to post Share on other sites More sharing options...
mgrayson3 Posted October 15, 2018 Author Share #30 Posted October 15, 2018 (edited) 1 hour ago, albertknappmd said: Nice work and in the end run, I do not see much difference... Furthermore, since everyone is going to modify their pictures in LR and PS, what difference does the initial result really make? 😥😋😎 Thank you. Anything is possible. It does matter how quickly and easily you can achieve your desired result. No one but you can determine that. So was this a waste of time? Perhaps. Not to me, of course. 😎 Edited October 15, 2018 by mgrayson3 Quote Link to post Share on other sites More sharing options...
albertknappmd Posted October 15, 2018 Share #31 Posted October 15, 2018 It is never a waste of time. It is an interesting result but in the end run all of the systems studied were so close to each other that no major conclusion can be drawn. We have issues like this in science all the time. 😎😎😎 1 Quote Link to post Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.