I came across this device recently. Kept forgetting about checking its specs. Seems to pack a lot of interesting features. Anyone seen it? Used it? Has anything to say about it? http://www.sekonic.com/products/c-700/overview.aspx Best / Roger
Looks like spectro with a built-in phone and a nice app. I’d love to have a simple spectro with Bluetooth and an app on the phone that provided that kind of readout. I like the "Is CRI Relevant In An LED World?” video at the bottom and would also like to hear if anyone here has used this lightmeter. Scott Martin www.on-sight.com
On Sep 21, 2015, at 6:40 AM, Roger Breton <graxx@videotron.ca> wrote:
I came across this device recently. Kept forgetting about checking its specs. Seems to pack a lot of interesting features.
Anyone seen it? Used it? Has anything to say about it?
http://www.sekonic.com/products/c-700/overview.aspx
Best / Roger
On Sep 21, 2015, at 4:40 AM, Roger Breton <graxx@videotron.ca> wrote:
Every time I notice it, I get excited...until I see the purchase price. For that much money, you can get an i1 Pro, a tablet, and Argyll Pro.... b&
I'm not rich by any means but I almost would have been interested if, at the same time as being a "handy" spectrometer, allowing instant light sources spectral analysis, it could have offered dumb light metering, for photography. After all, it does ambient and flash metering? I must say I am impressed by the claimed 1 nm spectral resolution. I don't know what it's worth but it breaks my heart that they stopped at 380nm in the UV range. Why couldn't they go down to 350-360? It would have made the measurements useful for ISO-3664:2009 certification. Still, I think it's a neat little device if it does what Sekonic claims it does. Keep in mind that, in metrology, cheap is not common. I agree that the i1pro has a lot going for it, even if it's not as "portable". / Roger -----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Ben Goren Sent: 21 septembre 2015 17:45 To: colorsync-users List <colorsync-users@lists.apple.com> Subject: Re: Sekonic C-700 On Sep 21, 2015, at 4:40 AM, Roger Breton <graxx@videotron.ca> wrote:
Every time I notice it, I get excited...until I see the purchase price. For that much money, you can get an i1 Pro, a tablet, and Argyll Pro.... b& _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/graxx%40videotron.ca This email sent to graxx@videotron.ca
On Sep 22, 2015, at 7:43 AM, Roger Breton <graxx@videotron.ca> wrote:
I must say I am impressed by the claimed 1 nm spectral resolution.
Arbitrary spectral resolution is no big deal; you just use narrower slits. But that cuts down on the transmission, either increasing the noise or requiring longer integration times or that sort of thing. In practice, 10nm is plenty "good enough" for graphic arts work, 5nm all you need, 3nm as much overkill as isn't ludicrous, and 1nm near pointless but makes for some impressive-looking charts and the like. Of course, for astrophotography, 1nm just gets you recognizable Fraunhofer lines and, as such, is barely adequate for introductory amateur educational purposes...I think serious astronomy these days is done with spectral resolutions of small fractions of an angstrom.
I don't know what it's worth but it breaks my heart that they stopped at 380nm in the UV range. Why couldn't they go down to 350-360?
I'm not sure that typical affordable commercial CMOS / CCD sensors are all that sensitive below 380 nm. IR cut filters are common in digital cameras, but I don't think UV cut filters are. I could be mistraken.
Keep in mind that, in metrology, cheap is not common.
Well...it's one of those "pick n of m" cases. I've got a spectroscope with a _very_ large viewing area that will trivially do 1 nm resolution with a ~$20 bill of materials, but it's large and unwieldily. You can stick a camera in the one end and use it for spectrometry, but you'll need to calibrate it against some other instrument (such as an i1) -- and you'll obviously be limited to the intersection of the two spectral ranges unless you want to get into the realm of educated guessing. Spectral resolution, though, is limited only by how small you can carve the slit plus the camera sensitivity. I've got a last few refinements I need to make before I'll write up full descriptions, plans, etc., etc., etc. b&
Ben,
In practice, 10nm is plenty "good enough" for graphic arts work, 5nm all you need, 3nm as much overkill as isn't ludicrous, and 1nm near pointless but makes for some impressive-looking charts and the like.
Most reflective instruments return data in traceable 10nm increments. That's fine for wide-band kind of colors like inks on paper. But to nail lighting down, 5nm increment is preferred, at least until the day we're done with spiky fluorescents overhead luminaires at press consoles and everywhere. Where do you get reliable 5nm data for measuring light sources from? To plug into ISO-3664 computations? / Roger
Please comment, on the Schneider B+W UV-IR-CUT filter. Anyone using this besides me? Cheers David David B. Miller, Pharm. D. 3809 Alabama Street Bellingham, Washington, 98226-4585 360 739 2826
On Sep 22, 2015, at 4:11 PM, Roger Breton <graxx@videotron.ca> wrote:
Where do you get reliable 5nm data for measuring light sources from? To plug into ISO-3664 computations?
First, I'm not doing any ISO or similar standards work. I use an i1 Pro for almost everything. My spectral camera model is at 5nm resolution...I started with 3nm but it got unwieldy and all the ICC data is at 5nm, and I haven't yet found any problems with 5nm. I've got a Perl script that converts the i1 Pro 3nm values to 5nm by averaging the inner 3nm values. Considering the 1i Pro has an optical resolution of 10nm, I don't feel like I'm losing anything. It might not be true 5nm going into the model, but it's more than 10nm. If I discover a need for more than ~5nm resolution, I'll do it with a camera an an homemade spectroscope. The spikiest light source I use for anything critical is is a PCB Einstein. I don't think I'd ever select any sort of fluorescent for critical work unless there simply wasn't any other option...the Einsteins are really good, and incandescents are also really good. I'd go with dim incandescents and multiple merged (median) exposures if necessary for noise before fluorescents. b&
participants (4)
-
Ben Goren
-
Roger Breton
-
Scott Martin
-
Spinnaker Photo Imaging Center