Posts Tagged ‘5D Mark II’

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How To Color Balance Mixed Lighting Sources

Tuesday, March 5th, 2013

I just finished a series of four blog posts talking about the various advantages and disadvantages of different types of lighting for photo and video work (the first post, with links to the others, is here), and why I’ve decided, for the time being, to use a mixed kit of fluorescent and LED lights. This kit is great and should serve my needs very well, but there is one hurdle that needs to be overcome first: while these lights are all advertised as “full spectrum” and “daylight balanced” at 5600K, in reality they all have visibly different color temperatures, so they need to be balanced with each other in order to work well being used together to light the same scene. In this post, I’m going to give step-by-step instructions on how I took three different lights with radically different white balances and balanced them to work together beautifully.

Before: Unbalanced

Before: Yuck. When white balancing for the mini LED panel on the left, the fluorescent softbox in the center is very green and the LED 1x1 on the right is slightly magenta.

In the image above, which I designed intentionally to exaggerate the color balance differences of the three lights, I placed (from left) a miniature LED panel, a fluorescent softbox and a 1×1 LED panel next to each other and aimed them at a uniformly white ceiling. The difference is striking (and awful).

Before: Yuck

Alternately, the same image above, only this time white balanced for the fluorescent soft box in the center, the LEDs on the sides are both overly magenta and orange.

As is, it would be very difficult to use these lights in a scene together without them appearing different colors. So they need to be balanced together. How to do this? Gels! Pulling out my collection of gels, I got to work.

I keep an assortment of gels to color balance pretty much anything (from left to right): CTOs, CTBs, Plus Greens and Minus Greens each in 1/8th, 1/4 and 1/2 densities. With this assortment, no matter which way a light is off balance, I can balance it.

Gels Gels Gels!

Gels Gels Gels!

In order to balance the three different lights (from three different manufacturers!) I started with the one that is most difficult to gel: the fluorescent (this is one of the biggest weaknesses of fluorescent lights in my opinion… they’re a pain to gel). I used that as my basis and then adjusted the other lights to match it.

It is possible to simply judge the color of a light visually in comparison to others next to it, like in the photos above, and to experiment with different gel combinations to get the lights to the point where they visually look the same to the eye, but “eyeballing” it like that is extremely difficult to do accurately; I have a very good eye for color (I scored a 19 on the X-Rite Online Color Acuity test! Take the test yourself, it’s fun!), and even I can’t achieve the level of precision that I want by eyeballing it. So to measure the color balance precisely I decided to use a couple of precision instruments: my camera and computer.

To start with, I set up a simple 18% neutral gray card on a light stand (I use this one from Amazon… it’s cheap and does the job well), along with a color chart. I lit the gray card and color chart with the fluorescent light (placing the light at an angle so that the light is illuminating the card but not reflecting glare). I then blacked out the windows in my office and shut off all the other light sources (overhead lights, computer monitors, etc.) so there was no “contamination” and I knew all the light hitting the gray card was from the light in question, and I took a still photo of the gray card and color chart with my Canon 5D Mark II camera in RAW format.

Gray Card and Color Chart

Gray card and color chart on stand for determining exact white balance of a particular light

I downloaded the photo onto my computer, and opened the file in Photoshop (you could also use Lightroom or any other application that can work with RAW files, I just happened to choose Photoshop). Using the White Balance Picker / eyedropper tool in the Adobe Camera Raw conversion screen (the same tool is in the Develop tab in Lightroom in the White Balance box), I sampled the 18% neutral gray card to set the proper white balance for the image, the values of which are then displayed in the white balance section on the right (it is a good idea to click a bunch of times in a few places on the gray card as the individual measurements will vary slightly, then average the values).

Sampling White Balance in Adobe Camera Raw

The White Balance Picker tool is the eyedropper icon near the top left. I sampled a spot on the neutral gray card, which gave me the white balance values shown in the white balance box at the top right.

Sure enough, I now saw numerically what I had seen visually on the wall: that fluorescent light was very, very green (+28 tint!). Since that is the light that was most off balance, ideally I would have gelled it to match the other lights, but since this light is so difficult to gel and the other are so much easier, I instead went the other way around and gelled the others to match this one.

With the temperature and tint white balance values for the fluorescent light in hand, I then repeated the process (blacking out the room, lighting the neutral gray card with a single light source, and shooting a photo) for each of my other lights and then found the white balance values for them as well (I found that my miniature panel has white balance values of 5100K temperature and -3 tint, and my 1×1 LED panel is 5050K temperature and +5 tint).

With that information, I then knew precisely how off balance my lights were from each other. I then added a gel to one of the lights, repeated the process of measuring the white balance values, and noted the numerical effect of a particular gel (bear in mind that as much as the gel manufacturers try to keep the color of their gels as pure as possible, a Plus Green gel will never be purely plus green…for example, my Rosco 1/4 Plus Green gels turned out to add +28 points of green tint, but also knocked off 300 degrees of temperature. But after measuring the color balance values of each light and the color effect of each gel, it was very straightforward to figure out which gels to add to each light to balance them together.

In the end, to balance my LED panels to my fluorescent lights, I needed to add 1/4 CTB and 3/8 Plus Green (one 1/4 and one 1/8) to my mini LED, and 1/8 CTB and 1/4 Plus Green to my 1×1 LED, which, while not numerically perfect, got my lights as closely balanced as possible with 1/8th-increment gels. Now I can comfortably use all of my lights in the same scene together and be confident that their colors will be balanced and visually indistinguishable.

After: I've Brought Balance to the Force

After: I've Brought Balance to the Force. While I can still see differences on this uniform white wall, in practical use these lights will never appear unbalanced.

 

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Fun in the Outdoors

Wednesday, September 19th, 2012

I’ve always had a passion for the outdoors; I love hiking, backpacking, camping, mountain biking, rock climbing and pretty much any other activity that gets me outside. Thankfully for me there is the potential for a lot of great overlap between my passions for the outdoors and for photography. I’ve always shot a lot of outdoor photography, but recently I’ve been making it a focus of my personal work.

The other night I went out with my REI backpacking tent, my 5D Mark II (it’s heavier than my 7D, but the low-light performance is better) and a tripod and hiked through the woods to a favorite spot of mine. I set up the tent, got my camera and tripod ready and waited for the best light, and then shot the image below. Given the unique lighting there was a fair amount of work in post to get this image to look the way I wanted it (the image below is actually a composite of three different images!), but when I was finished I was pretty happy with how it turned out.

(You probably can’t see it in a version this small, but as luck would have it, the Big Dipper constellation is clearly visible in the sky. Click the image to see the larger version!)

Tent By the Lake ©2012 Chris Conti Photography

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My Thoughts on the Canon 5D Mark III Camera

Friday, March 2nd, 2012

Canon finally announced the long-awaited 5D Mark III camera body early this morning. My thoughts?

I’m sure it’ll be a nice upgrade when my 5D Mark II dies.

That’s right, I will not be rushing out to buy one of these. I was waiting with as much anticipation for this camera as anyone, and was ready to hit the “preorder” button as soon as the listing came up on B&H. But after reading about the camera it does not appear that its features will be worth an immediate upgrade.

There were a few things I was hoping Canon would include in this camera:

1) a faster continuous shooting still frame rate

2) faster video framerate(s)

3) a better autofocus system

4) higher-quality video recording

1) and 4) were improved slightly, but not much. The 5D Mark II’s continuous shooting framerate is 3.9 frames per second. The 5D Mark III’s is 6fps. This is an improvement, but only by about 50% and still doesn’t even match the 7D’s 8fps. As far as video recording, the 5DmkIII uses a new interframe compression scheme and additional processing which may improve the quality of the video, but it still uses the same old 4:2:0 sampling scheme. 2) was not improved at all (the 5D3 can shoot 720 60p, but so can the 7D and, for that matter, so can a $200 GoPro camera… I wanted 1080 60p, which I think is very reasonable*). 3) really is the only one of these four things that was significantly improved. The 5D Mark III was given the same AF system as the 1Dx, Canon’s flagship camera body. It is a 61-point AF system with something like 40 cross-type AF points (the best kind). Also, it uses a tiny, 1.5% spot metering area (the circle is only 1.5% of the total area of the frame) which is great if you want to expose the shot very precisely for a specific area of the image.

Anyway, again, all in all, not worth buying immediately.

*: The 5D Mark III is equipped with one of Canon’s newest, most powerful image processors, the Digic 5+ (the same processor that the 1Dx contains, except the 1Dx has two of them), so it is very possible that the good folks at Magic Lantern will be able to engineer some third-party firmware for the 5D3 and if so, it is possible that they’ll be able to squeeze additional performance out of the camera. We’ll just have to wait and see on that one.

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Canon 5D Mark III in the wild?

Tuesday, January 24th, 2012

As every professional photographer knows, the as-yet-unreleased successor to the Canon 5D Mark II camera body has been an immensely anticipated new product. For non-photo professionals, think of it as the “new iPhone” of cameras: everybody’s talking about it, what features it’s going to have, what it’ll be able to do, how much it’ll cost, and most importantly, when it’s going to come out. The 5D Mark II is now over three years old, and is overdue for an update. There have long been rumors that its replacement will be called the 5D Mark III, but pretty much everything else about the camera has been a mystery. Canon sponsors (read: pays) a number of high-profile photographers and allows them early access to new, unreleased equipment and the rumor has been that these photographers have had their hands on the 5D Mark III for some time. These folks are all under legally binding contract not to talk about anything they see early though, so the pro photography world is holding its breath in anticipation.

Well, we just got the biggest hint yet. A wildlife photographer named Stephen Oachs (who is NOT sponsored by Canon and is not under NDA) is currently on safari in Kenya and spotted a Japanse man using unreleased equipment. Oachs, being a wildlife photographer on safari, had a camera and a long lens on hand, and snapped a number of photos of the man and the equipment he was using. The most important image is here:

Photo by Stephen Oachs

Stephen was even so kind as to publicly post the raw file of this photo as proof that it was not faked or manipulated in any way. After cropping and rotating the image for easier viewing, it looks like this:

Stephen Oachs' image, cropped and rotated

A few things are clear from this photo:

  • -The camera this man is using is not a 5D Mark II (the control layout is all wrong, among other things)
  • -It also isn’t a 7D (no pop-up flash and the button directly above and to the left of the rear scroll wheel doesn’t exist on a 7D)
  • -It also isn’t any version of a 1D (the battery grip is a screw-on attachment, not integral to the camera body)

 

So it is clear that this is an unreleased camera. It is possible that this is a replacement not for the 5D Mark II but the 7D (a “7D Mark II”?), but seems unlikely, since the 5D Mark II should be ahead of the 7D in terms of an update and since the optical viewfinder prism looks too big for the camera to be crop-sensor.

By the way, it is also clear that this unreleased camera includes substantial video functionality, since it includes a prominent still/video switch just like the 7D.

There are now inklings coming out about a Canon announcement on Feb. 7, so it sounds like photographers’ long wait for the mythical 5D Mark III may be about to end.

 

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Back to a Favorite Spot

Wednesday, August 24th, 2011

We’ve all got favorite places; places that for whatever reason we keep coming back to, whether it’s because they’re pretty, they’re comfortable, there are good people there who we enjoy spending time with, whatever.

The weather has been beautiful in Boston for the last couple of days (with the exception of that earthquake yesterday! Does that count as weather?), and I had some free time last night so I decided to go back to one of my favorite places in Boston for shooting at night.

The Longfellow Bridge connects Cambridge and Boston across the Charles river, and looks out on the part of the river known as the Sailing Basin, because as the widest, most open part of the river, the MIT, Harvard and other university sailing teams, as well as the public all use it as a great spot for sailing small boats. On any given afternoon there are dozens of sailboats on the water here.

This spot on the bridge is a favorite of mine because in addition to the great view of the river, from this vantage point there is also a great view of the Prudential building and the Hancock Tower, Boston’s two tallest skyscrapers, and the bridge faces southwest, meaning it is wonderful for shooting landscape photos at dusk.

"Charles River Basin": Canon 5D Mark II, Canon EF 17-40mm f/4L USM @ f/8, 17mm, 3.2 sec., ISO 160. ©Chris Conti Photography

For this image, because I knew I wanted both the natural light in the sky as well as the artificial lights inside the buildings to be visible with a nice balance between the two, it was important to wait for just the right light. I knew that would mean in this case that would mean a little bit after sunset, when the sky had dimmed sufficiently to not overpower the artificial lights (sunset photos can be gorgeous, but I’ve found that often the best light is actually after sunset, such as here). With the camera on the tripod and using a wide-angle lens (my trusty Canon 5D Mark II with the superb EF 17-40mm f/4L lens), I stopped the lens down to f/8 because shutter speed wasn’t going to be an issue (thank you, tripod) and I wanted the little bit of extra sharpness that comes with a smaller aperture. Using a remote cable release to fire the camera to avoid shake I fired a few frames to test exposure (the camera’s internal light meter here is a decent starting point but only a starting point) and play with a few different angles. Since I wasn’t using a tilt/shift lens and the camera needed to be angled up to get the framing I wanted, I had to do a bit of digital alteration in post (Photoshop’s “Lens Correction” function) to remove the distortion and make the buildings straight.

The result is what I think is a nice image, somewhat different than ones I’ve taken here before. It is by no means perfect though (if in fact an image can ever be), so I’m sure that I’ll be back to this spot again some time.

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