Macro bracket, part 5 : flash resolved

As I mentioned before, I wasn't sure if I was going to keep on using a Vivitar 285HV as my light source or not. I wanted to upgrade to a TTL flash for better consistency and rear-curtain sync, but funds are limited. A couple things have led me to order a 430EX II this morning, though.

First, I found that the guide numbers of the Yongnuo flash I was considering was understated by about a stop. This isn't really a big deal to me, except for the fact that it meant I'd have to use a higher power setting than I really want to, which means a longer flash pulse. When I considered that along with the uneven build quality, lack of a real warranty, and the other minor uncertainties that come with buying a third-party flash, I decided that I wasn't confident in putting my money there. All the little uncertainties add up to too much of a risk -- the YN-465 is about $15-$20 out of my comfort zone. (I will definitely say that the YN-460 II is not, and if I were looking for a manual flash right now, it'd be at the top of my list.)

The other thing is that I've noticed the foot of my Vivitar is starting to crack apart.  My off-camera cord has a slightly wobbly hotshoe, and the back-and-forth movement has put enough torque on the foot to start peeling away one of the flanges.  I've shimmed the hotshoe so it won't move anymore, but now the flash moves on its own.  It'll be fine as a remote flash, laying on its side with a receiver on the foot, but I don't trust it mounted to anything where the cracked flange has to support its weight.

So, I bit the bullet and ordered the 430EX II from Beach Camera's eBay store, which had the lowest price of any Canon authorized dealers after cashback.  I wish I'd noticed the damage to the Vivitar last week, when there was a $15 rebate, but what can you do...

I considered replacing the off-camera cord, which is the old "Canon Off Camera Shoe Cord 2" that was replaced by the OC-E3, but I think I've fixed the wobble (kind of a rotating looseness in the metal part of the hotshoe) by shimming it with thick paper.

Once the new flash arrives, I'll make a diffuser that fits on it in the same style as the one I made for the Vivitar, and I think I'll have my bracket finished.  I'll post photos explaining everything then.  In the meantime, I'll finish going through all the photos I took last week while I was visiting family in upstate New York.  I've already uploaded a whole gallery of sawfly photos, which I'm quite happy with -- my first real macros at a magnification higher than 1:1.  More very soon, I hope.

Designing a Macro Bracket, pt.4

Continued from Part 1, Part 2, and Part 3

I still have a few minor things to overcome with the bracket -- the raised post on the end comes off, but the screw is too long to mount anything to without it. I'm considering a few possible ways to work around this, but I've spent a lot of time talking about the bracket, and I'd like to move on. I'll definitely mention what I've got when I have a final solution.

So, the next phase is lighting. This is the whole point of the macro rig: dump enough light on the subject to get a good exposure, and dump it in an aesthetically appealing way. There are over-the-counter macro lighting solutions that work quite well, some of them better than what I'm making here. The MT-14EX ring light and MT-24EX twin light are quite good, but they're really, really expensive. I love macro photography, and as long as there's something to shoot at 1:1 my 100mm macro lens doesn't really come off the camera, but I can't justify spending hundreds of dollars on something I can only use for macro. So I use traditional flash units, which are less expensive and very versatile.

I already have a Vivitar 285HV, a cheap and popular manual-only flash. I'm considering upgrading it, if budget allows, but that's not certain yet. The ideal flash for this rig is lightweight, for obvious reasons, with enough power to get a fast flash pulse, and has TTL metering. A flash will give you hard, ugly light, so it also needs a diffuser of some kind.

The flash pulse is important for freezing motion: I shoot a lot of bugs, which are very active and very fast. Basically the lighting scenario I'm in most often is one where I'm shooting with a shutter speed close to my camera's fastest sync speed, or around 1/250, with an aperture of at least f/8, and usually f/11 to f/14, on an ISO of 100 to 200; the flash fires at 1/16th power, because it's so close to the subject. Without a flash, these settings would give you an unexposed black frame, except on the brightest of days.

So imagine, in slow-motion, what happens as you press the shutter with these settings: For a long 1/250th of a second, almost no light is falling on the sensor. Then, the flash fires a burst of light, and for the 1/16,000th of a second that it's pulsing, light floods into the camera and the sensor records that image, which by itself is a full exposure. The flash turns off, and the sensor is no longer receiving any light. At the end of that 1/250th of a second, the shutter closes, and the sensor sends its data -- all of it recorded in that 1/16,000th of a second -- to the camera's image processor.

The pulse duration of a powerful flash on a low setting is going to be much better at freezing motion than the fastest shutter speed your camera can do. Unfortunately, Canon doesn't release its speedlites' flash pulse duration, and even for the third-party companies that do, there are different ways of measuring it. So there's a bit of guesswork here; I think the only real thing we can do is assume that any moderately powerful flash is going to be fast enough, and choose between them on other grounds. It probably rules out small low-power flashes, and it definitely rules out constant light sources like LED lamps.

TTL isn't critical, and I don't feel like I need it at all for my non-macro stuff. It would be nice so I don't have to adjust the power level if I'm shooting a little further back, or decide to use a circular polarizer, for example. E-TTL 2 can make finer adjustments than just the one-stop power levels of the Vivitar 285HV. It also offers rear-curtain sync -- that would let me slow the shutter speed down to let more ambient in, and capture motion trails to show movement. These are generally convenience things, but I'd like to have them.

Two things I don't care about: Electronic zoom heads are a complete non-factor for me. High-speed sync is actually something I want to avoid using. It sounds like a great idea, using ambient as the main light, and high-speed sync as fill, but the way it works is to use thousands of low-power pulses through the entire exposure; when the subject is a fast-moving insect, that'll give a blurred picture -- like a strobe effect, but probably too close together to look cool.

Considering these things, I'd like to upgrade to the 430EX II if I can afford it. I go back and forth on the Yongnuo YN-465 and YN-467; I'd like to see a comparison to an official Canon flash in terms of build quality and reliability. Considering they cost less than half as much as the 430EX II, I'm willing to cut them a little slack, but I want good odds of getting more than a single season out of them before I drop money on one. Really it's the international shipping that gets me: if there were a supplier in the US who would handle replacements under warranty, I'd be much more likely to buy one. This all depends on my job situation, too, which is either seriously improving or completely disappearing in the next few weeks, and I don't have any idea which yet. No new toys if I'm unemployed. Fortunately for me, the flash I have works fine -- this is an entirely optional upgrade for me. (I wouldn't get the Vivitar as a macro flash if I were doing it again, though: it's too heavy, it has a beveled head that's hard to mount things on, and it's expensive compared to more modern competitors. On a super-tight budget, I'd go with the manual YN-460 or YN-460 II as a first flash, or on one of the E-TTL flashes I mentioned above.)

As for the diffuser, that's important for controlling the quality of the light. If you're already familiar with Strobist-style lighting, you know this already, and it's true for macro as well. The diffuser -- basically a small softbox -- is important because it makes the light bigger. The greater the angular size of the light source, the softer the shadows it makes. It also 'spreads out' the intensity of the lighting, so you can capture more detail in reflective surfaces without getting blown-out highlights. The plastic caps, like the Gary Fong-type diffusers, are no good here. They're designed for indoor use, and send light out in every direction to bounce back onto the subject. Outside, with nothing to bounce light off of at macro scales, they're just sending perfectly good light off into the void.

Right now I'm using the DIY flash diffusers described here on Myrmecos, albeit using a larger yogurt cup for my larger flash. It may be a bit too large, so I might remake it soon to be a bit shorter, but I'm getting great light from it. I'm using translucent vellum paper ($0.25 per sheet at my local stationary store) as the diffusion material, though Roscoe makes some professional materials for this exact purpose. That would be more durable, and more heat resistant as well -- though the general idea is to get the diffusion surface far enough away from the flash head to catch light from a wide area, so I'm not too concerned about the heat.

Designing a Macro Bracket

I'm starting to think about my macro rig for 2010, now the weather's getting nice enough to go outside again. I have a good general idea of what I want to do, given my budget constraints and what worked or didn't work last year.

(In my head, what I call the "rig" is everything involved: the camera, the lens and any tubes/rings/diopters that get you to macro magnifications, the flash(es) and related modifiers and cords, and the bracket that ties it all together.)

If you're just thinking about a macro bracket for the first time, it's a pretty simple build. It's basically the part of the rig that connects everything: usually a long flat plate that screws into the camera's tripod mount, with some sort of mount for the flash on the other end. The value comes from getting the flash away from the lens axis, to add depth and texture to the subject. The trade-off you're trying to minimize is the added weight of an off-axis light, and the hand-shake and fatigue that it introduces.

Over the next few weeks I'll build the thing, but here are my general parameters that I'm starting from:

Ergonomics
It has to have good balance. This is key. Wrist and finger strain are the number one reasons I'll pack it in before I get the shots I want. I picked up a Zeikos battery grip, partly to get my pinky in on the action and partly to move the center of gravity closer to my hand. I think I might get a hand strap as well -- that actually would help a lot, since it would take a lot of work away from the fingers.

Even with good balance, it still has to be relatively lightweight. I think a plastic plate will work better than the stainless steel ones I've been using. I could also drill my own mounting holes very easily. The trick would be finding one that's strong and inflexible.

Another problem with the stainless steel plate is that they scratch the camera body. I've already covered the one from last year with black duct tape -- it looks pretty good.

The bracket can't slip. The weight of the speedlight provides a lot of torque when it's moving, and it'll unscrew the plate from the camera and the flash mount. Part of my problem last year was using flat-head screws on plates with beveled mounting holes, or bevel-headed screws on flat mounting holes. This wasn't by choice: I was using pre-drilled plates from the hardware store and had to work with what they had. I tried to counter this with rubber grip tape, but that costs a few turns of the screw into the tripod mount -- again, insecure.

Utility
The bracket should hold the flash in a good position: about 10 o'clock or so. This hasn't been a big problem for me. The mount for the flash should be adjustable; I've been using a mini-ballhead, and may replace it with a cheap geared umbrella adapter for more stability and fine control. It would be nice if the distance from the camera could be adjusted, too, and I'll be thinking about that when I look at brackets.

In a perfect world, the bracket and flash mount would be so secure that I could shoot in portrait orientation without having anything slip or sag. The challenge here is that the weight of the flash will often turn the mounting screws counter-clockwise...

The rig should include a diffuser for the flash, basically a mini-softbox. I've just built a new one that I have high hopes for, out of a large yogurt container and some translucent vellum paper. This will get its own post once I've really seen how it works, but the key is getting a large apparent size for the light in a design that stays securely in the flash head. If I end up using an umbrella adapter, I may consider building something like a small umbrella.

The flash should be close enough and strong enough to use a low power level - ideally around 1/4 or 1/16 at ISO 100, f/8-f/14. This is to get a very fast flash pulse, which in macro lighting acts as the shutter speed -- the faster the flash, the better it freezes the image. With my 40D, I'm willing to go up to ISO 200, and in fact shot there all last summer.

Value
The DIY parts of the rig should be no more expensive than a store-bought solution, and it should be as reliable as one of equivalent cost.

Off-the-shelf components should be inexpensive. If they're not, they should be of very good quality and should be usable in non-macro photography.

It should be stable and sturdy enough that I won't need to tweak the design or replace parts over the summer.

The parts, especially the plate, should be made of easily available materials. I don't want to get something custom milled at ridiculous cost. Ideally something from the hardware store that I can cut or drill myself. But no false economy, either: I don't want to pay half-price for a half-assed solution.


Part 2: More thoughts on the bracket.
Part 3: Bracket solved.

ISO 102400

Canon and Nikon have both released cameras recently that have ridiculous ISO ranges. My 40D can get up to ISO 3200; the just-announced-today 1D Mark IV gets a full five more stops of sensitivity. I haven't seen any samples yet, though Vincent Laforet says the camera can basically see in the dark, and that ISO 6400 is at least as good as what we expect from ISO 1600.

And then think of some of the new image stabilization technology. Canon's new 100mm Macro has a new system that apparently can work well at 1:1 magnification. I don't know how well, but even if it works respectably well, that might give us another two stops.

I think this is going to enable some tremendously interesting things for macro shooters -- it will let us take some of the weight off the camera, which means staying out longer and being able to move the camera easily for better compositions. Imagine a rig designed for daylight shooting, with, instead of a heavy flash and diffuser, a scrim and a reflector on flexible mounts to modify the natural light. Or lightweight flashes with low guide numbers that are working at low/fast power levels. Both of these will still be able to shoot around f/11 or so, without having to pay nearly as much in noise.

Hopefully, this technology will filter down to my personal price range sooner rather than later...

Flash pulse duration

Chuck Westfall's October Tech Tips is out, and he answers a question regarding the flash pulse duration of Canon's speedlites. Canon doesn't publish these numbers so there's quite a bit of speculation, but he points out one thing that I didn't know: at lower power levels, the xenon bulbs used in the flashes are not as efficient as they are at high power. Therefore, a flash firing at 1/16th isn't necessarily firing 16 times faster than it does at full power, since it's putting out less than 1/16th as much light per millisecond.

Without actual numbers or the tools to do some testing, it's impossible to say how much it matters. It's probably still firing faster than it would at 1/4 or 1/8, which is important in flash-based macro because your flash pulse duration is, effectively, your shutter speed.

The bit I find most interesting is where he says "I suspect that if you use a higher power setting on the 430EX to match the output of the 550EX, the flash durations from both Speedlites will end up being very similar if not identical." I've been considering the 430EX II over the 270EX, on the assumption that they'd have similar pulse durations at full power, and therefore the 430EX II would be faster since I'd be using it at lower power levels. It may be that the 270EX at 1/2 or 1/4 power isn't as much of a compromise in speed as I had thought; in terms of price and weight, it's obviously the better choice for macro.

This may seem like nitpicking, but it does have real application for the small animal photography I like to do. On a warm, sunny day, it's simply not possible to get a sharp image of a fast-moving insect without a flash pulse fast enough to freeze its motion. 1/250th of a second is a looong time in that shooting scenario.

Lily Leaf Beetle

This handsome little beasty is a lily leaf beetle, an invasive insect from Europe that has chewed its way through the lilies of Montreal and New England. It's been called the 'scourge of Cambridge'. Apparently the University of Rhode Island has been experimenting with parasitoid controls -- i.e., another species that, in the beetle's natural range, uses (and kills) the beetle as part of its life cycle. Ichneumon wasps are a type of parasitoid, though they wouldn't touch these beetles.

I'm still very happy with the flash bracket I used to take this picture, except for two things: the weight at the front makes it difficult to stabilize, and I haven't found a good way to diffuse the light yet.

I'm considering picking up a 270EX or 430EX II to replace the Vivitar 285HV I'm using now. Both weight considerably less, and I expect E-TTL II would be helpful for macro work. The 270EX is tiny and cheap, but it's not terribly advanced. I'm also not sure if I would get the flash duration I want from a weak flash. When you lower the power on a flash, what you're really doing is lowering the amount of time the flash fires for, and faster flash pulses will freeze motion, like camera shake or wind, better than slow ones. So my thinking is that despite the extra weight of the 430EX II, it's a more powerful flash, and that might let me use a lower power setting than the 270EX or Vivitar 285HV. But naturally, both flashes cost money, which I don't have much of.

As for the diffusion problem, I'm still brainstorming. The problem is that I'm getting hot spots that lose all their detail -- look at the white glare on the lily leaf beetle's carapace. I'm also getting it on compound eyes and legs. I've got the flash in pretty close and firing it at 1/16th, so it's about as soft as it's going to get on its own. We'll see about this; I don't have a good idea for it yet.

A simple DIY macro flash bracket

Update: I like this bracket design better.

Off-camera flash is incredibly useful with macro photography, since at high magnifications you don't have a lot of light coming into the camera, and the high speed of the flash helps to eliminate camera shake. There are a number of products that will enable this -- flash brackets, wireless remotes, etc. -- but the dirty secret of photography is that things like this cost money. Sometimes, serious money. So I made a flash bracket that puts the flash about 8" from the camera, and can provide some adjustment of height as well. This doesn't sound like a lot, especially when thinking in strobist terms, but this is specifically for macro work, and 8" in macro is quite enough.



First, what I had been using was a Cactus V2s wireless radio trigger handheld, mounted on a mini-tripod, or just placed on the ground someplace nearby. The problem with all these is that if I want the flash to get close, I usually have to go handheld, and that sacrifices stability and balance of the camera. The angular size of a light source determines how soft or hard it appears on the subject, so when you're shooting a small insect, an unmodified strobe can work well at low power and a few inches away. Off-strobe modifiers, like diffusers and reflectors that help control the light, are simply not practical most of the time, especially when shooting skittish insects.

A macro flash bracket is different that a typical flash bracket used by, say, a wedding photographer. Those raise the flash height just enough to avoid red-eye. It's still basically on the lens-subject axis, just a few degrees off. A macro flash bracket like this is going to be considerably further off-axis when you consider that the subject is about a foot from the camera.

I used the following parts:

* A mini-ballhead from a tripod I already had. These would run like $12 new.
* A flash shoe mount with a 1/4-20 thread on the bottom. At first I used the Cactus V2s receiver, and later switched over to an off-camera cord. A generic cold shoe is like $6 on eBay; anything would work here.
* A trigger of some kind. If you use the off-camera cord, that'll do it and allow TTL; otherwise you'll probably need to use a PC cord terminal and manual mode on the flash. If you don't already have all the right cords and whatnot, just go with a third-party or used off-camera cord for simplicity.
* An 8" mending plate with counter-sunk holes. $2.99 from my local hardware store.
* Two 1/2" screws, 1/4-20. $0.67 each. I got the kind with the beveled head, since the holes in the mounting plate were countersunk. Thumb screws would be spendier but smarter, since you wouldn't have to carry a screwdriver to adjust anything. Whatever you use, make sure it's not the pointy kind :)

Giottos Mini Ballhead
Zeikos Off Camera Shoe Cord for Canon or Nikon
Stanley Hardware 8" Mending Plate
Electro Hardware 1/4-20x1/2 Thumb Screw (But you probably have 1/4-20 screws around the house if you're DIYing anything.)

Purchasing any needed parts through the links will support this site. Disclaimer: I haven't directly used any of them. I use a larger Giottos ballhead and wouldn't hesitate to use one of their mini ballheads here; the off-camera cords are sold through Amazon, who has a good return and exchange policy if they flake out; and the hardware is pretty generic; as long as your screw or bolt has a wide enough head to cover the mending plate holes, or if you use a washer, it's hard to go wrong with any of it. Of course, if you try any of these products based on my suggestion and they fail spectacularly, please let me know.

I mounted the ballhead to one side of the plate, and the receiver to the other. Then it's just a question of attaching the flash to the receiver and the camera to the ballhead. Even if you have none of the parts, you can put this together for about $20 new.



By using the ballhead, I get some control over the position of the flash. I can raise it or lower it a few inches, and of course bring it forward or backwards. The pics only show it side-by-side with the camera, but with a ballhead its position is only limited by the length of the plate and the camera itself. It also keeps the mending plate away from the camera -- the edges aren't terribly sharp, but they could superficially scratch the camera. I stuck some rubber tape over the flash end, even though I doubt I'd hurt myself on it. Also, make sure to line up the ballhead so that its side notches are parallel with the plate -- this will let it travel up and down.

Right now I'm triggering it with a PC sync cord. Even though I'm using the wireless receiver, its battery is starting to go and I'm getting banding at 1/250 shutter speed. I just ordered a used off-camera flash cord for $20 to swap with the receiver -- it'll get me a bottom-threaded shoe mount with better balance, and it should keep TTL functions if I ever decide to get a flash with TTL. Plus, I don't see the point of using wireless triggers this close to the camera.

I'll be really testing this out tomorrow, but I've taken one or two test shots already and it seems to work quite well.

Update: See my notes from my first outing with this bracket here. I've since replaced the Cactus receiver and PC cord with a 2' off-camera TTL cable and it's better in every way -- the balance is better, it's more securely mounted, it doesn't randomly disconnect, it's easier to position on either side, and when/if I can upgrade to a TTL flash, it'll come in even handier.

Off-camera flash

The most cost-effective piece of equipment any photographer can buy is a flash unit that can be triggered off-camera. Learning to use one effectively will do wonders for the quality of your photography, and Strobist is the place to learn it. (I mean, besides "wherever you use your camera". Obviously.) One of the main sponsors of the website, Midwest Photo, has just released the LumoPro LP120, a new flash that looks to be an excellent piece of gear.

The LP120 is completely manual -- you have to think about how you're using it and how you're making your exposure. But this is really not as hard as it sounds, and Strobist makes it pretty simple to learn. In exchange for being a little further up the learning curve than a TTL speedlight, it's a fraction of the price without sacrificing any of the control. It has many options for connecting to your camera, six power levels, the head zooms and swivels, and it has a two-year warranty backing it up.

I've shopped at Midwest Photo before and have been quite happy, and they're actively involved in the discussions at Strobist and on Flickr. It's great to see this kind of win-win situation, where we get good, inexpensive equipment, and a company worth doing business with makes a profit. I wish I could justify picking up an LP120, but I just got a Vivitar 285HV not too long ago. It, or the next generation, will definitely be the next flash I pick up though.