Over the past couple of weeks, I’ve been writing about my LED light project. This article is no different. There’s functionally two aspects of this project that I’m working on simultaneously. One is designing an actual LED Light panel, we the controller for one at least ,and the other is more investigative work on various control mechanisms and the required level of precision and accuracy for control.
The intent of this experiment is to begin to look at the accuracy of PWM control over LEDs, especially as they approach very low duty cycles.
Today I want to talk briefly about dynamic range, but not that of a camera sensor. Instead I want to talk about the dynamic range of a light.
As I mentioned in a previous blog post, I’m working on designing an LED Light Panel controller and part of designing such a thing is figuring out what the operating range of the light should be. Specifically I need to make decisions on two key factors, how far the light can be dimmed, and what kind of resolution I want to have in the dimming (e.g. 1/3-stop steps or 1/10-stop steps).
Now this may sound like an obvious answer? More is better right?
But this is going to be digitally controlled, and that means that it is subject to a whole host of “limitations”.
Quite a while back, before I learned the proper terminology, I wrote about the metameric failures here and here that occur when using non-tungsten light sources. These sources have become increasingly common and popular due to their low power consumption and low heat output, and solid state — LED — lighting forms the basis of my DIY lighting project exactly because of those reasons.
Since cheap LED light strips are the focus of this project, it seemed useful to make at least some rudimentary tests on the color quality of light. Since I don’t yet have the neutral or cool white LEDs that I intend to use for the final panels, I’ll have to revise this in the future to deal with that, but rudimentary tests now at least make some considerations to the quality of light that can be achieved.
I just finished soldering together my first test LED light panel, it’s only 492 lumens worth of LEDs, but it’s good enough to start testing a lot of the electronics. So things are slowly moving forward. Today though, I want to talk a bit about power, or rather batteries.
I first started thinking about power back when I conceived of the idea. Back then, I was still targeting a >6000 lumen 114 W 1×1 panel, and the idea of using a 19 V laptop power brick for the power supply. I’m still working on that idea for large panels and as a non-battery option, however, when I started thinking about smaller test panels, I started thinking about using batteries.
My first iterative test panel is only 4×6 inches, and with standard density LED strips, only draws 6 watts. Even if I scaled it up to high density LED strips, I’m still only talking about 12 watts of draw. Factor in some overhead for inefficiencies and a good estimate is somewhere around 15 watts, which is well into the range of batteries.
The question then becomes choosing a battery pack and dealing with the engineering needed to get it to work.
I’ll try and be brief with this as there’s little in the way of real content here.
Personally, my continuous lighting situation is a bit of a mess. Most of my fixtures are designed for tungsten photo floods. A situation that I quickly realized was largely untenable due to both the heat and power consumption. I’ve tried replacing the lamps with photo grade CFLs, and even LEDs. However, the brightness and control over the light just wasn’t there compared to the tungsten lamps.
After considering the options, LEDs are clearly the optimal solution in terms of color quality and brightness for the power used. However, good quality LED light panels are expensive, and the cheap ones are marginal at best.
The 3rd option, instead of spending a lot for good panels or a little for crap panels for now and then more later for good ones, is to build okay panels from the start.
A couple of weeks ago, I ran across a YouTube video showing how to build a LED light panel from inexpensive self-adhesive under counter LED light strips and other components readily available on Amazon. The idea intrigued me, and the LED strips are cheap enough that at least mediocre quality lights can be build for less than what it costs to buy many of the cheap panels you can find on Amazon.
Of course, once I started pondering the idea, I realized that there was a lot of room to experiment with how best to control the lights. Sure there’s probably a bit of lazy involved here, but remote control can be handy when the light is somewhere inconvenient to reach. Moreover, since my initial thought was to use a micro controller instead of directly connected potentiometer to control the lights anyway, the door was open to all kinds of control options from ethernet, to WiFi, to Bluetooth, and so on.
That brings me mostly to this post.
Without dragging this out any longer, I wanted to put something up to explain the sudden influx of electronics and engineering content on what’s supposed to be a photography site. So that’s the deal, over the next several months I’m going to be posting a lot of content about the design and construction of a LED controller that can be used for video/still light panels and where the potential problems are. Heck, even if you’re not interested in building one, you might be interested in some of the issues. So stay tuned.
Canon recently announced their latest in their line of, well I’m not quite sure what to call them — semi-pro, or maybe non-production pro level photo printers, the ImagePROGRAF Pro–1000. Slotting in a tier above the Pixma Pro–1, and bringing a 17 inch platen to the market segment. At $1300 it’s not a cheap printer, but then again neither was the $1000 Pixma Pro–1.
I’ve been printing off and on for 4 or 5 years now, and while I’m far from an expert on the matter, I have learned quite a bit. The important thing that I’ve come to realize is that printing for yourself should not necessarily be looked at as an economical way to make prints. It really is hard to compete with a production lab, especially at small — 8×10 or smaller — print sizes.
At the same time, quality, control over the quality, and options, are important to many of us, be us a professionals or just a serious hobbyists. We wouldn’t buy expensive cameras, spend time researching the best lenses we can afford, and ultimately wouldn’t spend the hours and hours practicing and perfecting our crafts if there wasn’t something in that that was important to us.
So the big question in my mind is what does the ImagePROGRAF Pro–1000 offer us and is it a good deal?
Adobe’s Photoshop Lightroom has been around for almost a decade, and in that time, Adobe hasn’t really changed the interface in any meaningful way, that is, at least, until now. With the September 2015 update for Lightroom CC, or Lightroom 6.2 for those non-Creative Cloud subscribers, Adobe has finally taken to changing Lightroom’s import screen.
Why the import screen and why now?
Presumably, or at least hopefully, this will be just the tip of a much needed overhaul in Lightroom’s UI and the Import screen was the easiest place for Adobe to start. How this plays out for the rest of Lightroom remains to be seen.
Lets start by quickly looking at the old Lightroom import screen.
The styling is dated, at least if by modern flat UI standards. Further, the layout is confusing if you’re not use to dealing with it. There’s clearly some logic to it, but a lot of settings seem scattered around to some degree.
The new 2015 screen is well different.
Adobe clearly seems to have embraced the whole flat UI aesthetic. Unfortunately, the rest of Lightroom doesn’t follow this new styling. At least for the time being, the new import screen does feel somewhat out of place.
Icy Strait point, and the nearby town of Hoonah, is not a destination for most Alaskan cruises. Located off the Icy Straits in Port Frederick, an inlet more than a port as many would expect, this is as close to untouched Alaska as I think you can reasonably get on a cruise. Even Port Frederic as a “port” is tenuous at best. Cruise ships, of which I believe only one can be in “port” at a time, do not dock here. Instead they anchor in the inlet off Cannery Point. Passengers are then tendered ashore.
On shore, the old fish cannery has been converted into a visitors center, native’s craft shop, and eatery. It’s also the jumping off point for the world’s longest zip line, and all the other excursions that are available out of Icy Strait Point and Hoonah.
Broadly speaking, there are three things to do in Hoonah as far as excursions go. You can ride the zip-line, experience some traditional Alaskan performances and buy some traditional crafts, or go view wildlife (mostly bears and whales). If you’re looking for another instance of the cliché diamond and gold shops that litter the docks in every other port of call, you’re not going to find that here, and that’s just fine by me.
Since I’m writing about whale watching in this article it should be pretty obvious what I did. I would have liked to have gone on a bear watching excursion as well, however, at the time I was there, May, and with the time frame we were in port, that wasn’t really practical.
Back in May I went on an Alaska cruise, and being a photographer I obviously took the opportunity to shoot as much as I possible could. I also took my laptop, with Lightroom 6 on it, so I could work on my images as I went instead of being overwhelmed by a ton of pictures when I got home.
I can’t say I learned an awful lot new in the process, even though I’ve never worked this way before, but I thought I’d at least talk about it a little and go over some of the trade offs and processes in working on a laptop in the field then bringing that back and getting it on your desktop at home.
Also, while I’m currently using the latest version of Lightroom, everything I’m going to cover applies to previous versions as well.
Importing and Previews
While my laptop is every bit as capable of rendering standard or 1:1 previews as fast as my desktop, doing so uses power and I’m not always plugged in when I’m importing images. Moreover, rendering previews at import time will render the previews for every image that is imported. This has two potential impacts on the mobile user.
First, the obvious point, every image rendered requires the CPU to compute the rendered preview, this uses more power than the alternative of not rendering the previews.
The second consideration is less obvious but can be far more of a problem. Every standard or 1:1 preview that’s rendered consumes disk space that could potentially be used or needed to store copies of images from another card.
Normally on my desktop I render 1:1 previews on every import. This is of course computational expensive, and results in a lot larger preview cache, however, I can afford both the power and disk usage for the benefit of having a more responsive environment when I start editing and developing my images.
There are places on this planet that one can visit and never be able to really express what it was like to be there. The Grand Canyon, for example, it doesn’t matter how big the picture is or how high of resolution, you can never quite convey the experience of actually being there. Glacier bay is one of these places, and unlike the Grand Canyon, Glacier Bay is far more ephemeral and fundamentally more endangered.
Glacier bay as a whole is a quite big, it’s 63 miles from the entrance to the bay from the Icy Straight, to the furthest end of the Tarr Inlet. There are currently 50 named glaciers in the bounds of the park, of which 7 are tidewater glaciers. All of this is to say that even if you’re traveling on your own small boat, there’s quite a lot of ground to cover and quite a lot of varied scenes to see and photograph. If you, like me, are on a cruise ship, you can expect to cover even less ground and spend even less time at any given location.
Depending on the cruise line and the ships schedule, and any other mitigating circumstances the exact experience in Glacier Bay will vary. Most ships cruise up the western side of the bay to the Johns Hopkins and Tarr Inlets.
In the worst case, like the Holland America cruise that charged up the bay ahead of our ship, is that the ship heads straight to the Tarr inlet and Margerie and Grand Pacific glaciers; does it’s rotation, and heads right back out of the park.
Most ships will probably sail up the Johns Hopkins inlet which means a close pass—actually two, one in each direction—of the Lampaugh glacier (tidewater) and a distant view (~6 miles) of the Johns Hopkins glacier.