The blog index, organized by topic, has been updated. There are now over 300 articles. Check it out!
Sunday, 24 July 2011
Saturday, 23 July 2011
Digital Photography Review, one of the world's most popular websites and forums, now has a For Sale / Wanted section! Check it out here.
Edit: DPReview also now has notifications for forum activity. That means you can be notified by email when someone replies to a thread you're participating in. Awesome!
Edit: DPReview also now has notifications for forum activity. That means you can be notified by email when someone replies to a thread you're participating in. Awesome!
Friday, 22 July 2011
If you read lighting blogs and hang out at lighting forums, one of the things you'll often hear is that a bare bulb (aka bare tube) flash is superior to a speedlight, which has a rectangular reflector and fresnel lens. Such is the mystique of bare bulb that ebay prices for old Sunpak 120J flashes are in the $200+ range (in past years they have reached over $300).
Is the quality of light from a bare bulb flash indeed better than that of a speedlight? I did an experiment to test this. Hit the jump to see the results!
CONVENTIONAL WISDOM
There are many reasons given for the bare bulb flash's superiority. One is that the light can be sent in almost all directions whereas with a speedlight the light only goes forward. When used with a softbox, the bare bulb flash will illuminate the sides of the softbox, thus illuminating the softbox face more evenly than a softbox lit with a speedlight. It has been said that a smaller softbox lit with a bare bulb is the equivalent of a softbox with a 75% larger surface area lit with a speedlight.
A bare bulb flash also produces a round light pattern compared to the somewhat unnatural rectangular light pattern of a speedlight. In a square or octagon softbox, the bare bulb flash would theoretically spread its light more evenly in the softbox than can a speedlight.
There are other reasons for the superiority of a bare bulb such as the option to use it with a parabolic reflector, which is said to have better quality light compared to a square reflector of a speedlight. However, I thought it would be fun to try an experiment to see if a bare bulb flash does indeed give better quality light in a softbox.
THE CHALLENGE
In the blue corner, wearing black with white trim, weighing in with a guide number of 160 feet, an old school favorite among wedding photographers and a veteran with decades of service under its belt, fighting out of Hauppauge, New York, the legendary battery-powered strobe, the Quantum Qflash!
In the red corner, wearing black with red trim, weighing in with a guide number of 125 feet, the former Nikon flagship flash and still the most powerful flash that Nikon has ever produced, fighting out of Sendai, Japan, the venerable workhorse, the Nikon SB-800!
The fighting grounds: a 48" Fotodiox EZ-Pro octagon softbox with both the baffle and front diffuser attached. Both flashes will be mounted to a CowboyStudio Speedlight Bracket T (the SB-800 will be positioned with the head in a horizontal as opposed to vertical orientation). Both flashes will be triggered by a Radiopopper JrX (the non-Studio version).
The rules: To fight the SB-800 (with about 60-75ws of power), the 200ws Qflash will not use its PXC module (which would otherwise add 200ws), and will operate at half the manual power setting of the SB-800, so that the flashes can fight at the catchweight of 100ws.
Round 1 will compare the light distribution on the face of the softbox.
Round 2 will compare the light distribution on a wall illuminated by the softbox.
Round 3 will compare the softbox light on a mannequin.
... And there goes the bell!
ROUND 1: FRONT PANEL
Each flash was mounted on the softbox. I then took a photo of the face of the softbox. These shots were at ISO 200, f/4, 1/250. The SB-800 was triggered at 1/32 power while the X2 was at 1/64 power. I used the SB-800 both in 24mm zoom and with the Nikon SW-10H dome diffuser (similar to the Sto-fen Omnibounce) at 14mm zoom.
To help evaluate the resulting photos, I converted the luminosity of the photos into a spectrum of distinct colors. Here are the results:
SB-800 at 24mm zoom: Doesn't look too bad but when we look at the luminosity map, we see that the distribution of light is not very even, with more than half the softbox being red, about 1/3 being yellow and 1/3 being green, and the intensity is not evenly distributed across the panel either. Note that the variation of intensity is greater across the vertical axis (varies from red to green) than the horizontal axis (varies from red to yellow). It may have looked more even if I took the shot perfectly straight on but I would guess the pattern is due to the rectangular shape of the speedlight's light pattern.
SB-800 with diffuser: Looks pretty even except at the center (which is partly blocked by the runner hub of the octagon softbox) and the parts that are not diffused by the inner baffle. Even when we look at the luminosity map, the distribution looks quite even, with most of the softbox appearing at the same yellow intensity, although there are parts that are red and parts that are green. The distribution also appears much more regular than that of the SB-800 without diffuser. Another noteworthy result is that the diminution in intensity is moderate and certainly does not overcome the advantage of a more even light distribution.
Bare tube flash: Looks remarkably even except at the parts not diffused by the inner baffle. The luminosity map shows that the distribution is very regular and the variation of intensity is gradual except at the parts of the softbox not diffused by the baffle.
WINNER: Bare tube flash, though the SB-800 with diffuser worked surprisingly well. Don't count the SB-800 out yet though, because the front panel light distribution isn't significant by itself. What matters is the actual light pattern on the subject.
ROUND 2: LIGHT PATTERN ON WALL
In this round, I aimed the softbox at a wall. I took shots of the light pattern as seen from directly behind the softbox as well as from the side of the softbox (so that we can see the middle of the light pattern). As in the previous round, these shots were also at ISO 200, f/4, 1/250. The SB-800 was triggered at 1/32 power while the X2 was at 1/64 power.
The results:
What I was looking for when looking at the light pattern from behind the softbox is primarily the shape of the light pattern. When I look at the images (even diagonally), the shape looks very similar. Now let's have a look at the pattern of the light intensity:
SB-800 at 24mm zoom: the intensity varies from green to blue but is distributed very regularly. Notwithstanding the uneven light pattern on the front panel, the actual light pattern is round and there is barely a hotspot.
SB-800 with diffuser: the intensity is very slightly diminished compared to the SB-800 without diffuser but perhaps more importantly, there is almost no hotspot at all. The light looks very even and the intensity varies in a regular pattern.
Bare tube flash: looks quite even, but not more so than an SB-800 at 24mm zoom. The hotspot looks more intense than that of the SB-800 at 24mm zoom and certainly the SB-800 with diffuser, but because the X2 was also significantly brighter, we can't definitively say that the bare tube flash is less even than the SB-800 unless we could re-do the test at a diminished intensity for the X2 (I would have had to decrease the ISO because the X2 was already at the minimum power).
WINNER: SB-800 with diffuser, though the X2 results may improve if the intensity can be made more comparable.
ROUND 3: MANNEQUIN HEAD
I don't take photos of softbox panels or walls -- I take photos of people. So the most important test for me is how the light looks on a person. In this round, I compared shots of a mannequin head. The shots here were at ISO 640, 1/250, f/4. The SB-800 was at 1/32 while the X2 was at 1/64.
The softbox was around 45 degrees to the vertical and around 15-30 degrees to the subject's right. Here's what the setup looked like:
Results:
I converted the comparison shots to black and white to remove color temperature as a factor. Except for the brighter exposure of the bare bulb flash, the results look almost identical. For those who want to pixel peep, here are the shots again:
 |
| bare SB-800 |
 |
| SB-800 with diffuser |
 |
| bare bulb flash |
If you see any significant difference, please feel welcome to post in the comments.
WINNER: This round is a draw, which means... under these conditions and with the modifier I used, I saw no evidence of the bare bulb's superiority (unless you like taking photos of softbox panels and brick walls).
Monday, 18 July 2011
 |
| Final Result, hit the jump to find out how it was done |
I had some fun yesterday with a glass shard that I took from a car's broken windshield. When I saw the broken pieces of glass I immediately thought of my macro lens and flashes, click through to see what I did.
I decided to start by putting this piece of broken glass on a glass table and take an ambient light only shot, I used my newly acquired Manfrotto tripod with a ball head (review coming soon), set the camera to aperture priority mode, chose f/10 for a large depth of field, set ISO to 100 (no need for a higher number since nothing is moving) and finally I used the self timer to prevent camera shake and fired away, this is what I got:
 |
| Same piece of glass, ambient light only |
The above picture looks nice but is not striking enough, so I decided to go on with my plan and use flashes, I had a vague idea about how to light this piece of glass, but I knew that I had to light it using two flashes and that one of them should be from beneath.
I started with one flash only at 1/32 power and the shutter speed at max sync speed to kill the ambient (the rest of my settings were the same, f/10, ISO 100), and started taking pictures and pointing my flash from different positions, left, right, up and down. After looking at the differences I decided to light the glass with one flash from the right side at 1/32 power and zoomed to 14mm (using the diffuser panel), and another flash from the bottom left at 1/16 power and zoomed to ~ 70mm. Here's how the setup looked like:
I also tried different gels on the flash for more interesting colors, I ended up with a blue gel on the top flash and a red one on the bottom one. To compensate for the lost power due to gels I increased the ISO to 200. The gels I used in this setup are home made, I posted about them here.
POST PROCESSING
I had to do some post processing to get the image at the top, a macro lens (close focusing distances in general) plus flash lighting have a maddening ability to show every-single-speck-of-dust!!!
I cleaned the table several times, yet it was never clean enough, so I decided to ignore it and remove it in post.
Post processing was very easy, I did a strong bit of sharpening (more than I usually do) to show the inner fractures inside the glass shard, and then I used the adjustment brush with exposure = -4 to remove all the dust specs and undesired reflections around the glass shard, it also helped to pull the fill light slider all the way to the right to see what parts needed removal with the adjustment brush. Here's the final result again for your convenience:
 |
| Final Result, click to see a larger version |
I believe that this is a mediocre result, nothing spectacular, but nonetheless it was a fun experiment and I consider it as a new ground on my way to improve my product photography skills. What do you think?
Sunday, 17 July 2011
Using speedlights with modifiers that were originally designed for strobes sometimes entails compromises. The ingenious Speedlight Bracket T from CowboyStudio mitigates those disadvantages and helps your modifiers perform at their best by positioning your speedlight for optimum performance. This bracket also enables you to use a wider variety of modifiers.
Note: This post is part of a series that will cover equipment reviews for committed enthusiasts. Read more about Toys for the Big Kids here.
HOW LIGHT DIFFERS BETWEEN SPEEDLIGHTS AND STROBES
Speedlights have a different light pattern compared to strobes because a speedlight's flashtube is inside the flash head whereas strobes have flashtubes that are exposed (i.e. bare bulb), allowing you the option of sending the light out in almost all directions instead of a cone.
When speedlights are used for modifiers that were originally designed for strobes, modifiers' performance can suffer:
Umbrellas. Many strobes have built-in holes for umbrellas that allow the flashtube to sit close to the umbrella's axis. On the other hand, the typical umbrella bracket for speedlights places the speedlight head a significant distance from the axis of an umbrella, resulting in less even lighting of the umbrella.
 |
| Speedlight on typical umbrella bracket. 25-inch umbrella shown. |
Softbox. When the bare bulb of a studio light is placed in the softbox, the light is scattered everywhere within the box -- some to the front, where it is diffused by the front panel, but much of the light also illuminates the reflective sides of the softbox, from which it is further diffused by the front panel, spreading the light more evenly across the face of the softbox.
When a speedlight is used with a softbox, most of the light is sent forward, and less so on the sides of the box. A hotspot becomes more likely, which arguably reduces the effective size of the softbox. It is possible to use a dome diffuser to simulate a bare bulb but with some softbox brackets for speedlights, the flash head is partly outside the softbox wasting a significant portion of the light.
Beauty Dish.
Each beauty dish has a different focal point depending on the curvature and design of the dish, and the size and position of the deflector. A speedlight that is not at the focal point produces different light patterns. See the heading "Fine-Tuning the Beauty Dish Output" here. Using a speedlight with a beauty dish that was designed for a specific strobe often means that the speedlight won't be positioned at the focal point.
COWBOYSTUDIO SPEEDLIGHT BRACKET T
The CowboyStudio Speedlight Bracket T addresses the foregoing issues to some extent, and adds other benefits. With this bracket, the speedlight is mounted horizontally. It has a ring that fits modifiers compatible with the Bowens S-mount. The bracket also has a tiltable lightstand mount with umbrella hole.
The bracket includes several parts, with some thoughtful design features:
1 - the Bowens mount
2 - a coldshoe. Similar in design to the Stroboframe cold shoe, except that it has a protrusion at the bottom that fits in the groove of the L-bracket (#4) so that the cold shoe will not rotate. It also has a screw to prevent a flash from sliding off one end.
3 - a second cold shoe plus a washer. This cold shoe allows the flash to be rotated. It has a hole for flashes with locking pins.
4 - L-bracket. Supports the flash. The groove allows the flash to be adjusted vertically (within a 2-inch range). The L-bracket can slide along the length of the rail (#7). Reversible.
5 - 1/4-20 screw. Secures the cold shoe or a flash with female 1/4-20 insert to the L-bracket (#4). Includes a metal washer and a rubber washer. The rubber washer has a notch to accommodate the protrusion of the coldshoe (#2).
6 - thumbscrews to attach the mount (#1) to the rail (#7). Tools not required.
7 - Rail. Around 8 inches long. The bottom of the rail includes an umbrella holder and a tiltable lightstand mount. The lightstand mount includes grooves to resist movement once tightened.
8 - thumbscrew. This is attached at the opposite end of the rail to prevent the L-bracket (#4) from sliding off the rail.
9 - spigot - can be inserted in the lightstand mount to accommodate either a 1/4-20 or 3/8-16 insert.
BENEFITS:
This bracket has a simple design but offers several benefits:
1. The flash is on-axis. By placing the flash much closer to the axis of an umbrella, the bracket allows a flash to illuminate an umbrella more evenly.
2. The flash can be adjusted in 3 axes (vertically, horizontally, plus rotation). Unlike other speedlight bracket designs, this bracket design has tremendous range of travel along the horizontal axis of the bracket -- a range of around 8 inches. In the shot above, you can see that even though the flash is horizontally positioned in the bracket, it may be moved further away from the umbrella than with a typical umbrella bracket.
The range of horizontal travel is a critical feature because it allows the flash to be moved inside the modifier to the modifier's focal point. Together with a dome diffuser, this addresses at least part of the softbox problem and beauty dish positioning problem.
The range of horizontal travel is a critical feature because it allows the flash to be moved inside the modifier to the modifier's focal point. Together with a dome diffuser, this addresses at least part of the softbox problem and beauty dish positioning problem.
3. Compatible with both speedlights and large flash (e.g. Quantum, Sunpak 120J, Vivitar, Armatar, etc.).
 |
| Some bracket designs are compatible with large flashes but the position of the flash is far from ideal. |
 |
| This bracket allows a large flash to be perfectly positioned. |
4. Allows a wide variety of modifiers that are available for Bowens/Calumet. Speedlights are still playing catch up to studio strobes when it comes to availability of modifiers. With this bracket, you can use the myriad of modifiers compatible with Bowens/Calumet.
5. Replaces both an umbrella bracket and speedlight softbox bracket. You won't need to carry separate brackets for an umbrella or speedlight softbox.
6. Sturdier than the generic speedlight softbox bracket.
 |
| Some speedlight brackets have a thin speedring that is supported with only one screw. |
|
| The Speedlight Bracket T has a mount that is very sturdy and is attached to the rail with two thumbscrews. |
CheetahStand.com has a very similar bracket that costs around $68 at the time of this writing. I got my Speedlight Bracket T from Amazon for around $30 with free shipping.
8. Good quality construction. The fit and finish on this is not perfect but most of the parts are metal and should last several years.
Disadvantages:
1. No support for the front of the flash. The flash is supported only by the L-bracket. The front end of the flash is not at all supported, which places a lot of strain on the hot shoe. By comparison, the Cheetah Speed Pro Bracket Mark II has an adjustable vertical support.
2. The Bowens mount has to be removed to pack it. It takes a couple of minutes to attach the mount. With repeated packing and unpacking, I'm also concerned about losing the thumbscrews.
SUMMARY:
The Speedlight Bracket T is the perfect complement for your flash and will bring it one step closer to strobes. It is sturdily built and well designed, with many thoughtful features. At $30, this is a must-buy accessory for your lights if you want to get the most from your modifiers (and your lights). Highly recommended.
Tuesday, 12 July 2011
Just an update about my Meike MK-RC7 flash triggers. One of my
receivers died for no apparent reason. By dead, I mean that it won't
turn on at all even if I replace the battery. I didn't drop it or get
it wet. Notably it is the receiver that I use more often. The other
receiver that I use less often is still functioning (for now).
receivers died for no apparent reason. By dead, I mean that it won't
turn on at all even if I replace the battery. I didn't drop it or get
it wet. Notably it is the receiver that I use more often. The other
receiver that I use less often is still functioning (for now).
In this post, we will have a look at a softbox for speedlights. This post is part of a series that will cover equipment reviews for committed enthusiasts. Read more about Toys for the Big Kids here.
WHY USE A SOFTBOX?
Softboxes are bulkier and more costly than umbrellas. It is hard to use a softbox without a light stand or an assistant. On the other hand, umbrellas are cheap, fairly portable, and can be employed relatively quickly, even by a solo photographer. Why bother with a softbox?
One issue with umbrellas is that they offer less control. A shoot-through umbrella spreads light everywhere. If photography is drawing with light, then a shoot-through umbrella is like splashing your canvas with a bucket of paint.
A reflective umbrella offers more control than a shoot-through umbrella and is a closer match to a softbox. However, a reflective umbrella (especially a silver one) is more specular and has a greater tendency to have a hotspot (the light is less even across the umbrella). With a softbox, the light is bounced around the reflective insides of the softbox and then sent through one or two diffusion panels. By the time the light goes through the panels, it is much more even than that of a reflective umbrella.
There are now umbrella-softbox hybrids that combine some of the best qualities of an umbrella with those of a softbox. These umbrellaboxes look like reflective umbrellas, except that they have a diffusion panel (where you insert the flash). See this post. The result: it has a much more even lighting across the face, just like a softbox, yet it is as portable (and almost as inexpensive) as an umbrella.
 |
| Umbrellabox aka softbrella, umbrellasoft, brollybox |
However, a softbox has a couple of advantages over an umbrellabox. First, an umbrellabox has a pole sticking out the middle. That means there is a limit to how close you can bring it to your subject. Some umbrellas, such as the Photek Softlighter have a partially removable pole that addresses this concern to some extent.
Second, if you want the tight control offered by a grid, a softbox is your only option for now. I have yet to see a grid made for an umbrellabox.
SPEEDLIGHT SOFTBOX
Softboxes have traditionally been used with strobes, and were originally designed for use in a studio. The speedlight softbox is a little different from a studio softbox because it's designed to be portable, is quick and easy to setup, and includes a bracket made for speedlights.
Lastolite probably deserves credit for making speedlight softboxes popular with their collapsible Ezybox design. Look for an upcoming review of the Ezybox by my co-author mshafik.
Meanwhile, similar designs have since appeared from third parties. Mine is by CowboyStudio and I got it from Amazon for $55. The CowboyStudio softbox that I got includes:
- a 24" collapsible softbox
- bracket for speedlights
- removable inner baffle
- removable front diffuser
- 50-degree grid
- round mask
- small round bag for the softbox
- and a bag for the kit.
Softbox
The softbox is described as being 24 inches. In reality, when unfolded, each side is only about 21 inches.
I like this softbox design because of the setup speed. Typical studio softboxes are assembled with rods connected to a speedring. The rods are in turn inserted into the corners of the softbox. Check out this video of a typical studio softbox:
As you can see it can take a few minutes to put it together.
The softbox here is entirely different and instead comes as a triangle that simply and instantly pops up (like some car shades) into the shape of a softbox. The optional inner baffle has metal hooks that can then be connected to loops inside the softbox. The front diffuser is then attached via velcro to the lip of the softbox. The optional round mask or grid can also be attached via velcro.
Folding the softbox back into a triangle for storage is just as easy. The triangle can be further folded into a smaller circle for maximum portability.
Besides ease of setting up the softbox, another feature I like is that the front is recessed, which helps improve control and reduce spill.
Bracket
This kit comes with an adjustable bracket that can accommodate speedlights of various sizes as well as some larger flashes.
 |
| Assembled bracket |
 |
| Bracket components |
 |
| Bracket shown with Yongnuo YN-560 (same size as Canon 580EX) and a Quantum X2 battery-powered strobe |
The bracket can be mounted on a light stand's 5/8" stud. Alternatively, the bracket can accommodate a spigot with female 1/4-20 insert (not included) so that the bracket can be mounted on a tripod.
EVENNESS OF LIGHT
Given that softboxes were originally intended for strobes with bare bulbs instead of speedlights that send most of their light forward, I was concerned about how evenly the softbox would be lit. In the worst case scenario, if the speedlight would light only a small portion of the softbox, it would act as a smaller modifier.
I took some test shots to see the evenness of the light on the face of the softbox. I first took test shots with only the front diffuser (without the internal baffle). Even with an SB-800's built-in diffuser in place and the flash zoomed to 14mm, the light was not very even:
I then tried using a dome diffuser attachment (similar to the Sto-fen omnibounce). There was almost no improvement:
I finally attached the internal baffle. The speedlight was zoomed to 24mm without the built-in diffuser or the dome diffuser. It was a significant improvement.
Note that I did not adjust the power level on the flash. Judging from the luminosity map, there was also not much power lost.
SAMPLE SHOTS
Earlier, my wife had volunteered for photos because she was going to get her hair done. Afterward though, she didn't like how her hair turned out (looked fine to me). So I had to resort to a self-portrait.
In this first shot, my key light was the 24" softbox (powered by a Nikon SB-800, triggered by a Radiopopper JrX). To show the effect of the softbox, I didn't use any fill. Behind me was a seamless gray paper supported by a Linco background support. I also attached an SB-80DX and an SB-26 behind and to both sides on 1/64 power, using a super clamp to attach them to the background stands and triggering them optically with their built-in slaves. The shot is almost straight out of the camera with minimal adjustments to give you a better idea of what the softbox light would really look like.
In the next shot, I kept the same setup but added on-axis fill light with an ABR800 ringflash and increased the power of the kickers to 1/16. I also moved myself farther from the background.
Finally, I kept the same setup as the shot above, except that I attached the grid. Note that the light on the background has been reduced.
SUMMARY
Strengths
- Setup is much quicker than studio softboxes.
- Inner baffle is effective at making the light more even.
- Bracket can accommodate larger flashes.
- Kit includes grid and round mask.
- Much lower price compared to Lastolite Ezybox or the virtually identical CheetahStand Q-Box.
Weaknesses
- Bracket does not allow some flash heads to be inserted completely in the softbox.
- Smaller than advertised.
- Ring on bracket is secured with only one screw. The ring can be twisted to the left or right, and is not very sturdy.
- Shape of softbox is not parabolic. Light is not parallel.
OTHER RESOURCES
Comparison between the Cheetah Q-box (substantially similar to this softbox) and the Lastolite Ezybox.
COMING UP ON TOYS FOR THE BIG KIDS:
- a bracket that can replace the bracket included with the speedlight softbox, and can expand the number of modifiers available to your speedlight or battery-powered strobe.
- bare bulb advantages.
- introduction to Quantum flashes.
- review of the Paul C. Buff ABR800 ring flash.
- other cool modifiers such as an octagon softbox and a beauty dish.
Subscribe to:
Posts (Atom)
