Models and Cougars and Bears – Oh My!

One of the most interested shoots I’ve done was when I worked for a company that manufactured copier parts. As part of a promotional campaign, we were doing a shoot that needed a live cougar and a bear.

We found a place about an hour away that had the animals we needed — they were “animal actors.” The place had about 100 acres of land and every animal that’s native to Minnesota, including a pack of wolves and a few bison. It’s at places like this that the vast majority of wildlife photography is actually shot. They have some land, the photographer chooses the animals he wants, and the animal handlers bring them out and try to coax them into doing what the photographer wants.

Our first shoot needed the cougar, also known as a mountain lion. The handler drove up with Rocky in a cage in the back of a pickup. Rocky was huge, but sweet. He was rubbing his head against the bars for the handler to scratch his ears for all the world like a giant kitty. He was adorable.

And then we got the safety talk. That was a sobering experience. It went something like this:

“Don’t have any food in your pockets, and don’t chew gum. He’s attracted to the smells and might attack. Don’t make any sudden movements. Don’t try to pet him. Don’t make eye contact with him – that might make him attack. Everyone stand together in a group, and don’t leave the group. Cougars are attracted to prey that is alone. These two guys have cattle prods and will stand with the group. Everyone stay here.

“Okay Brian, you can come over here to get the shot.”

And sure enough as I walked away from the group, Rocky – previously sitting there drowsing – suddenly got very, very interested in me. I watched him tracking my movement, then caught myself looking him in the eyes. It was amazing how deadly this previously adorable cat suddenly seemed.

And I can only imagine how the model felt, who had to be standing right next to him. Just off frame in this photo is the handler hiding behind a tree with a cattle prod. When the model took the chain off the cougar, it was supposed to walk away (handler luring it out with some meat). But instead it just turned and looked up at the model, considering whether to eat her I presume.

In the end the shoot went more or less as planned. Once Rocky took off into the woods for a bit of a run (and in the process going – I’m dead serious here – through a fence, blowing it apart) but the trainer lured him back with some cat & mouse games.

Then we switched to the bears, even bigger and more massive than the cougar, but strangely less threatening. Immediately the extra guys with cattle prods went away and the trainer came out with a bag full of gummy bears.

“Here,” he said to one of the models. “Put this in your lips and the bear will eat it out of your mouth!”

What is ISO?

In photography, ISO is a measure of how sensitive our film is to light. In digital photography we still use ISO (technically ISO Equivalent) to express how sensitive our imaging sensor is to light.

We’re going to get into some interesting details of ISO below, but first we’re going to hit just the basics, the Cliff’s Notes version for those who just need the answers, and need ’em now.

The ISO Digital Photography Basics

In digital photography ISO refers to how sensitive your imaging sensor is to light. However, the more sensitive it is to light, the more noise your picture will have.

  • ISO and ASA are the same thing
  • A lower ISO value is generally a higher quality, with less noise
  • A lower ISO value requires more light
  • A higher ISO value is generally lower quality, with more noise
  • A higher ISO value needs less light
  • In bright sunlight you’ll probably want to shoot at ISO 100 and enjoy excellent quality photos
  • In dark or indoor environments you’ll need a higher ISO, ISO 800, or 1600, or higher. These photos will have more noise, thus a lower quality.

ISO vs ASA

ASA refers to the American Standards Association and is now a defunct and outdated measurement of film speed. It’s still often used on film packages though. ISO refers to the International Standardization Organization and is the accepted standard for film speed. Whenever something refers to the ASA of film, it’s the same thing as the ISO.

But use the term ISO: it’s more accurate. ASA is what your grandfather used.

Film Grain and Digital Gain

Back in the film days a higher ISO value meant larger grain on your film. The larger grain was more light sensitive, so it exposed faster. So when you shot with higher ISO film — like ISO 800 — you ended up with a grainer picture. But grainy wasn’t all bad. Grain gave pictures an interesting quality that some photographers deliberately sought out.

Now that we’re in the digital photography age, our ISO Equivalent is increasing the sensitivity of our photo sensor. This means that the photo sensor is now able to pick up a fainter light signal — but the flipside is that it’s also going to have more noise. By cranking up the sensitivity of the sensor, it is actually generating noise. Think of it like a speaker with that background hiss — when you crank it up, that faint hiss gets louder and louder. The higher your ISO is, the more noise you have.

Unlike film grain, noise is just plain ugly, and you really don’t want it there. Noise on a digital photo is colored specs or a speckled image, and in a very noisy photo they are immediately obvious, distracting, and unattractive.

Unfortunately, there is no “right” ISO, or “highest” ISO for a decent picture. The reason is that different cameras (or different sensors) have a different sensitivity to noise. Every camera has a range of ISOs that give acceptable image quality, and that range is different from camera to camera, from sensor to sensor.

Size Matters: Why Megapixels Ain’t Everything

In most things, a bigger sensor is better. Larger sensors tend also to have larger pixels. These larger pixels are less sensitive to noise. So a low-end consumer camera with a 1/1.8 in sensor might have incredibly noisy shots at ISO 400. But a standard SLR with a APS sensor can shoot ISO 400 with no noticeable noise, and may not get that bad until ISO 1600. Move up a step again to the full-sized sensor and you may be able to shoot at ISO 3200 with less noise than that cheap point & shoot was at ISO 400.

But the size of the sensor isn’t really the factor here — it’s really the size of those pixels that matters. This is where the constant obsession with more megapixels! starts to get us in trouble. You can fit more megapixels on the same-sized sensor by making those pixels smaller. But make them too small and you’re going to increase their sensitivity to noise. So you can easily have a camera with more megapixels that takes worse shots, even when blown up to the same size, because of the noise.

So megapixels ain’t everything. In fact, a 12 megapixel full-frame camera will have better shots, and better blow-ups than a 16 megapixel APS sensor camera. But then, a full frame sensor with 16 megapixels will be better still.

ISO & Stops

ISO is a very convenient and logical measurement of sensor sensitivity because it’s beautifully set up to use our stop system. If you double the ISO, you are doubling the amount of light (or sensitivity to light). If you halve the ISO, you are halving the amount of light in your exposure.

Thus if your exposure is correct at ISO 400, but you want better quality, you can stop down 1 stop to ISO 200, but you’ll have to lower your shutter speed or open your apeture by one stop to compensate.

Digital Camera Native ISO

Every digital camera has a “native” ISO setting, this is the setting that gives the camera it’s highest possible quality shot (lowest noise). In most cases this is the lowest ISO setting that the camera offers, often ISO 100.

However, some cameras have a native setting higher than their lowest possible ISO — most Nikon cameras have a native ISO of 200. The camera still offers ISO 100 (or lower), but in actuality ISO 200 will have the best signal to noise ratio. Be sure to take a moment and find out what your camera’s native ISO is, so you know where to set it for the best quality shots (assuming the lighting conditions will allow for it).

Minnehaha

I woke up the other day to some lovely early fall weather. It was overcast and just barely drizzling. Seemed like some ideal weather to finally go out and start on some fall pictures. Sadly before then we’ve been having lots of sunny warm fall days. Lovely for going for a walk, but crummy for photography.

I headed down to my favorite water source, Minnehaha Falls — a lovely creek and waterfall in the heart of Minneapolis with a mile or so of trail from the falls down to the Minnesota river.

6 sec at f22 on ISO 100 with 18mm focal length using a NDx4 filter

I wandered around a bit and took the obligatory shot from the base of the falls — I’ve taken a hundred of these but I can’t seem to go there without taking a new one every time — then I wandered downstream to see what there was to see.

The water level was very high for this late in the year, which gave some nice texture to the fast-flowing water. I stopped about a half-mile down to take some long exposure shots of a fork in the creek where the water flows around some rocks, and I was pretty happy with the scene.

Minnehaha Creek

6 sec at f36 on ISO 100 with 170mm focal length using a NDx6 filter

And no sooner did I start taking shots than the clouds finally opened up and started seriously raining. I dashed under some thicker trees and tried to get a few more shots in of the rain — but of course with the creek flowing so fast anyway you couldn’t even see the rain hitting the water. It just made the picture look muddy, as it also darkened considerably.

I finally tucked my camera under my jacket and made the run back up the trail for safety. But it’s early fall yet, with the trees just starting to turn. I figure we’ve got another solid week of better and better fall colors, and then another week or two at the tail end. So hopefully some pleasant fall shots will be coming up.

I Hate Butterflies

I learned recently that the Minnesota Zoo has a butterfly garden. In addition to demonstrating how incredibly long it’s been since I’ve been to the zoo — a shame — this also presented what I thought was a fantastic photography opportunity! An enclosed building with hundreds and hundreds of butterflies of all kinds, just waiting to be shot. Fantastic!

Well, not so much.

I grabbed my camera and spent a good amount of time wandering from flower to flower, shooting butterflies, having butterflies land on me, whisk out of frame just before I pressed the shutter, or delightfully stay still as if posing.

Monarch Butterfly

1/320th at f5.6 on ISO 400 with 200mm focal length

I got home and wasn’t terribly thrilled with the shots. I grabbed a macro lens and went back, did more shooting and went home again disappointed. Then I realized the horrible truth, something I should have remembered from my Heinlein:

“Butterflies are not insects. They are self-propelled flowers.”
– R. Heinlein

I also hate flowers…

I learned a long, long time ago — back in the wee youth of my photography life — that it was frickin hard to take a good picture of a flower. And the reason it’s so hard is that it’s so easy to take a good picture of a flower. Bear with me a sec — I swear this makes sense.

Say you want to shoot a flower. You zoom in nice and close, leave everything on auto, and then you press the shutter. You now have a glorious picture with bright, vibrant colors offset by a dark, out of focus background. It’s lovely. And it’s just like every other picture every other person takes of a flower.

Butterfly on flower

1/1000th at f7.1 on ISO 400 with 200mm focal length

The reason it’s so hard to take a really good shot of a flower is that it’s so easy to take a good shot of a flower.

There are a bazillion shots of flower that are all good, that all look just like your shot. Your shot doesn’t stand out, nothing makes it remarkable, special. After all “good” and “bad” are qualitative terms, not quantitative. It’s graded on a curve. Something is only good if it’s substantially better than most of the pack.

I’m passing on self-propelled flowers for now

So after two shoots I ended up with a bunch of perfectly acceptable and fairly average shots of butterflies. The best I got, I think, was a shot of a moth on some peeling bark, nicely backlit.

Cecropia Moth

1/90th at f5.6 on ISO 400 with 200mm focal length

I suspect the way to get some truly stunning butterfly shots is to actually shoot them in the air — midflight, perfectly in focus and with their wings spread just so.

I do not have the patience for that. Not nearly. And I’m not sure the nice people guarding the butterfly garden and herding children away would have the patience for me to sit there that long either. So for the time being I’ve decided to take my revenge on the damned butterflies the old fashioned way: by outliving them.

Strobe Misadventures, Part 3: Strobe Flash Duration Answers

In part 1 I got some new monolight strobes and saw some strange results suggesting the flash duration was much longer than the 1/600th – 1/1,000th that was listed. In part 2 we did some crude testing of the strobe flash duration and verified that yes, it was indeed the flash duration and not something else that was off.

After the strobe testing I finally did some research and discovered the answer: yes the strobe flash duration was much shorter than it seemed it should have been, and the reason has to do with the way that manufacturers measure the flash duration.

Flash Duration – T.5 vs T.1

When a flash goes off, it gets up to 100% brightness really fast, then trails off mush more slowly. Because you can never say for certain exactly where the point is that you’re back to ambient light, flash durations are measured in terms of how long they are over a certain percentage of their brightness.

Most manufactures measure flash duration as T.5, or the duration that the flash is over 50% of its brightness — the amount of time from half brightness to full brightness and back to half brightness again. The problem with this is that the flash curve gets really long on the tail end, and even though it’s less than 50% of maximum brightness, that’s still plenty of light to expose.

The more accurate measurement in terms of establishing the stop motion capabilities of the flash is T.1 — the duration of time that the flash is 10% brightness or greater. This is about three times as long as the T.5 measurement.

Monolight Flash Duration, T.1 vs T.5 measurements.

Thus that 1/600th flash duration, as reported my the manufacturer, is suddenly only a 1/200th or so duration. Plenty slow enough for motion blur, especially if you’re using a longer focal length.

Furthermore, for most monolight strobes — like my lovely Flashpoint 1820a — when you turn the power down (as I was) you actually get a longer duration, not a shorter one like you might think.

The Monolight Strobe Solution

There are basically three solutions here. Firstly you can just get yet faster strobes. Be sure to check the T.1 rating on them so you know how fast they’ll really be. Of course faster strobes tend to be far more expensive. If you want really, really fastness, you’ll want to use flash heads (but that’s a whole series of stuff for another day).

If getting much more expensive strobes isn’t a great solution (which it is not for me) then solution #2 is just to put the camera on a tripod, which you should really be in the habit of doing anyway, even if that’s a habit that I’ve never developed.

Finally we have the WoodJr solution, which is to go to the max sync speed of my camera. I had been shooting with the default flash shutter speed, which for some reason my D200 thought should be 1/30th of a second. However, the maximum sync speed of the D200 is actually 1/250th of a second. While this isn’t blindingly fast, it’s plenty fast to avoid any hand-shake blur. In effect it’s just cutting off the tail end of the strobe (and I had to turn the strobes up / open the aperture to compensate) but I still got great, even, consistent lighting every shot.

Once I popped my camera to 1/250th I went back into the studio and had no more hand shake blur issues at all, and I’m back to loving my strobes to death.

1/250th at f10 on ISO 100 with 38mm focal length

1/250th at f9 on ISO 100 with 26mm focal length

Strobe Misadventures, Part 2

Having established in Strobe Misadventures Part 1 that something was amiss with my focus, I promptly set out to do some testing to find out what it was. The focus could be off on my camera. I could be blitheringly unable to use the auto-focus. The flash duration of the strobes could be insanely slower than reported. Or I could be so hyped up from years of over-imbibing caffeine that my hands shake violently in a way my shell-shocked brain refuses to acknowledge.

It seemed to me the easiest thing to cross of the list was the flash duration of the strobes. Admittedly, this also gave me the chance to play with them some more, which may have influenced the decision.

I grabbed some paper from the printer and jotted down a handful of crude tests then grabbed a friend to hold them for me and be blinded by a series of flashes. My concept here was simple: take a control shot with the camera on the tripod. Then, with the camera still mounted on the tripod, have the model move her hand around and different speeds, to verify that we’re getting no blur there. Then take the camera off the tripod and take some shots with spastic, over-exaggerated shaky hands.

This isn’t the most scientific experiment here: my definitions of speed include “fast, medium, slow.” But the point is a 1/600 – 1/1,000 of a second flash duration should easily stop anything but the speediest of hand motions.

Here are the test shots, all taken at 44mm, f11, ISO 100.

The control test. Focus is good here, which also suggests there's nothing wrong with the camera's auto-focus.

Here the model is moving her hand up and down furiously. Clearly that's a lot of motion blur.

Here the model is moving her hand at a moderate rate, as though lazily fanning herself. We *still* have motion blur! Oh noes!

And here in the spastic shaky cam, with the model standing still, we still do not have a sharp image.

Without question we are seeing that the flash duration is apparently much, much slower than thought. The room was very dark, so there was no chance of ambient light affecting things. No, we’re seeing something that I’d normally attribute to something like a 1/125th shutter speed.

But… that’s not possible, is it?

The shocking answers next time in part 3: WoodJr just looks it up on the internet like he should have done in the first place!

Strobe Misadventures, Part 1

It was with great excitement that I unpacked my first monolight strobes, a pair of Flashpoint 1820a 900 watt/second strobes. Up until just recently I had always made due with continuous lighting — the lights that also doubled as video lights for video projects.

But of course I had all the problems that everyone has with continuous studio lights. With 1,750 watts of lights (requiring 2 circuits) I was still struggling to get better than 1/60th of a second at 24mm and ISO 400 on full shots. I just needed so much light. And of course they were hot.

The temperature in the room was easily 10 degrees higher within minutes of turning on the lights — and another 10 degrees in front of the lights. My models didn’t just have sweating problems — after a while they simply burst into flame, and as you can imagine this made cleanup a chore.

But model combustion aside, the bigger issue was brightness and what it did to my shutter speed. You can pretty safely guess that any studio shot I take that I showed to my father, the conversation will go pretty much like this:

WoodJr: Hey, here’s some recent shots I took.

WoodSr: They’re out of focus.

WoodJr: No… no they’re okay.

WoodSr: They aren’t tack sharp. Did you use a tripod?

WoodJr: … No. I couldn’t. I was suspended above the model from cables… in a 300 mph wind… underwater. I couldn‘t use a tripod.

WoodSr: Well that’s why they aren’t sharp. Camera blur.

But no longer! With these strobes I no longer have to care about shutter speed! They fire at the speed of light, c, 186,000 miles per second. Well, more importantly the flash duration is — optimistically, but I’m of an optimistic mindset with these strobes — 1/1000th of a second. Unless I’m using a crazy long lens, which I’m not, the studio room isn’t that big, there is no way I’ll get camera blur ever again.

I can finally show shots to my father and have him exclaim “Dear boy! These are as sharp as your very clever mind!”

So I quickly badgered a friend into posing as I tested out the lights. The weather was against us with a nasty and humid 92 degrees — so much for no more sweat — but I’m happy to report the model never once burst into flame.

And I was delighted with the strobes. They were bright. Stopped down to 1/4 power I was still getting f8 at ISO 100. It was fantastic! I had flexibility I’ve never had before. The lights didn’t have to be just on the outside of the frame. I could move them across the room if I wanted. And as they weren’t within a few degrees of the surface of the sun, I could toss whatever kind of filters or material I wanted over them.

Then I got back to the computer, to look through the shots, and saw several shots like this one:

This shot is… not sharp. In fact, it looks very much like blur caused by camera movement. Suspiciously so. But at 1/1000th of a second, that shouldn’t be happening. Okay, optimism aside, the low end of the flash duration is 1/600th of a second. Still plenty fast to stop any incidental motion.

Was it possible that I was legitimately out of focus? Does the auto-focus of my camera require adjustment? Are my strobes somehow insanely slower than they should be?

The only way to find out is to run some tests!

Part 2 of Strobe Misadventures: the disturbing results of some crude testing!

Night River

I was out camping along the St. Croix river for a few blisteringly hot days hoping to relax, do some swimming, some reading, and of course take some photos. As always when I’m not backpacking, I brought my entire camera bag with me and as always when I’m camping, I went most of the trip without finding anything much to take pictures of (though this may have been aided by 90+ degree temperatures, horrible humidity, and swarms of mosquitoes).

Several times during the day I saw bald eagles flying around on the other side of the river, but when I popped by 200-400mm lens on I still couldn’t get in close enough for a good shot. Not that it would have mattered a lot if I did — with the birds constantly swooping over the river, I couldn’t keep them in frame for more than a fraction of a second.

Finally after a big storm the first night I was sitting around the fire around 2am when the fog started rolling in across the river, illuminated by the nearly full moon through the clouds. This, I finally thought, could make for a decent shot.

I tossed the camera up on the tripod and tested out a few exposures until settling on this. Shot at 24mm at f3.8 on bulb setting with a cable release, ISO 100, for about 1 minute (I was counting — and chatting with my campmate —  so the time may not be that exact).

I’m always happy to return from any trip with a shot that I’m pleased with, and always frustrated to return without any decent shots. I’m quite fond of this one — I like the muddy foggy look of it and thus I’m declaring the trip a success!

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PhotoBug Blog

Photo Bug is the home of Brian's very occasionally updated photography journal. Posts are sporadic, and I keep swearing that some day I'll dig through the archives and start filling things up. Some day...


 
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