Secret Weapon

The secret's out of the bag! Want to see what two full-time nature photographers have in their weapons arsenals for capturing very quick critters? Check out the new articles by Tom Vezo and Joe McDonald on the home page. If you've had experiences with or questions about this secret weapon, let's hear them here.

The PhotoTrap seems to be an interesting product. I considered purchasing it a few years ago but didn't --due to size, cost, and poor instruction manual. The new version seems smaller and much improved. I actually looked at the product on the PhotoTrap website a few weeks ago and went back to review the specifications and features today. Unfortunately the website has just recently been updated and is not fully functional. Unless I misunderstood what I read earlier (and I can't view the info today), Bill Forbes stated that most of his sensor setups exhibited a 20 millisecond tripping delay, except for method #3 as described in the article--which he said was much faster (but no specifics on how fast). A 20 millisecond delay is significant when added to the 40-50 millisecond delay within the best of today's cameras. It is also disappointing when you consider that the ShutterBeam and Time Machine (both of which I now use) have delays in the 1-2 microsecond range. If I am mistaken (and hopefully I am), then the PhotoTrap is definitely a product I would be interested in purchasing. Joe McDonald says the tripping is instantaneous, but I distincly remember reading about a 20 millisecond delay. Hopefully more info on the specifications will be forthcoming. This image was taken with the Time Machine, which allows the connection of two sensors to the unit in parallel. When either beam is broken, the camera fires. This is a great feature as it allows you to capture images of the bird either arriving or leaving the nest. Just set one sensor near each edge of the frame. With the 40-50 millisecond time delay in the camera, the bird should hopefully be centered in the frame whether it is arriving or leaving. Before this, I had to decide ahead of time whether I wanted images of the bird arriving or leaving and place the sensor near the appropriate frame edge. With two sensors in parallel, it doubles the number of possible images with each visit to the nest.

Wow, what timing. I've spent too much of the past few weeks researching just this sort of thing with a view to building something, or at least trying to.

I'm considering buying one too, mostly to photograph birds arriving at a feeder or large mammals on forest trails (tapirs, jaguars, etc). Nice article.

One thing I didn't understand correctly... it says that the Photo Trap can be used to fire either a camera or a flash... what's the point of firing only a flash? As I understand, it should trip the camera, so that the camera will fire the remote flashes. Am I missing something??

The point of firing a flash is that there is a much shorter lag time than when firing a camera. The camera would need to be on bulb and triggered previously and then when the flash is fired, it will expose the frame and then you release bulb.

Another technique is to trigger a 1-4" second exposure with one photo trap and then a second trap fires your flash. Makes capturing a bird or bat in flight a lot easier as there is a much shorter lag time. Dealing with long bulb exposures are a big draw back.

Drew

Oh I see... yeah leaving it on bulb would be very bad, specially for remote shots (those you are far from the camera), not to mention exposure issues.

Buying 2 photo traps is not very good too... I guess I'll just have to get used to the small lag, I wonder how bad that is though.

It varies with camera but it is something like 50 miliseconds. Doesn't sound like much but a flying bird can easily travel a foot or more during this time. It's a guess and check system. At least with digital you can see the result and then adjust in the field. Those that started this with film had to wait to develop film and then readjust the next trip out.

Drew

Bulb use is useless in daylight. I have been able to use a Beam Tripper in full sun but it requires an aperture of f18-22 at ISO 100 and flash sync speed of 1/250s. F16 will work in partial sun or cloudy bright conditions, but will often give some ambient light ghosting in full sun. Bird flight speed varies. The key is to capture the image as the bird is slowing down to land or just taking off. With a time lag in the 40-50 millisec range, many birds will travel only about a body's length during that time. In the days of film, I had to use a polaroid back on a second Nikon camera body to check lighting and time lag. It is much easier with digital.

I just got off the phone with Bill Forbes and he was very helpful in answering my questions concerning the PhotoTrap. To make a long story short, I decided to purchase one. I will try it out and post my opinion regarding its performance in comparison to the ShutterBeam and Time Machine.

Ed, great warbler shot! The lag time problems and questions addressed above are a major concern, but whether or not a lag time is created by the camera or the tripper or both, the net result is one simply has to account for it. The easiest way to do so is by first shooting wide and having your subject travel parallel to your film plane so you can see precisely how far a subject travels in the time between tripping the sensor and the camera firing. Once that's done, its fairly easy to prefocus or compose to account for that distance and be reasonably successful. The barn swallows I'm shooting right now, I've found, travel at varying speeds, so not all of my shots are spot-on. Sometimes the tail is in focus and not the head, and sometimes neither is, but most, fortunately, are sharp.
The Model 33 Photo Trap has 'virtually' no delay, but regardless, successfully using the Photo Trap, or any such device, requires one doing their homework (shoot wide and parallel, first) and doing a great lighting job, like Ed has certainly done with the posted prothonotary warbler. It often takes me several days to really fine-tune my focus and composition, and I consider my work with the Photo Trap a long-term investment, not an instantly gratifying snapshot.
Drew's comment to Octovio about using flash is completely accurate, but let me just reenforce what Drew said, and that is that the camera's shutter must be open -- either on Bulb or a long timed exposure - so that the sensor is exposed when the flash fires. I've used this technique a lot with bats, but rarely with other nature subjects because of the issues of ambient light.
Last, when using ambient light and flash, the former is always an issue because of ghosting. If your shutter speed/aperture combination is enough to underexpose the ambient light, ghosting is eliminated, but you are likely to end up with a black background. This can only be eliminated by directing flashes on a background, either a true background or an artificial one. Ed's warbler, I'd guess, has such a background placed behind the birds, and is illumianted by flash to create a natural look. If you don't do that, you'll have warblers or barn swallows 'flying at night' since the background will be black.

Ed Erkes wrote:I just got off the phone with Bill Forbes and he was very helpful in answering my questions concerning the PhotoTrap. To make a long story short, I decided to purchase one. I will try it out and post my opinion regarding its performance in comparison to the ShutterBeam and Time Machine.

I'm curious what you found out differently about the Photo Trap that made you decide to go and purchase it (after your initial concerns about the delay)? Was it simply a matter of 'go ahead, why don't you test it out and see for yourself how it compares to your existing photo triggers?' Looking forward to your findings on the product.

I'm probably stating the obvious but this looks like a really fun product. I use to sit for extended periods of time overlooking nest boxes from a distance waiting for birds to exit and enter. With the Photo Trap I can just leave my camera there to take those shots automatically (and placed closer if needed) and go take photos of other birds or critters in the area. Certain owls are active only when it gets dark. For some time now I have wondered how I could photograph Saw-whet Owls taking off. This device may just be the answer. I may have the chance again this Fall.

I missed it this year but not far from where I live there was a family of Eastern Screech Owls that fledged last month. I plan to go back next year at the same time and hopefully use this device to get some night shots (the person on whose property these owls fledged...and nested, I believe...tells me they're active like from 8:30pm to 10pm on her property. I never did return because, well, there just isn't enough light by then. I have photographed owls at night but only when they were easy to approach, slow flying....actually hovering....and on public property where I could move around freely.

I just returned from vacation and my PhotoTrap arrived while I was gone. I've just finished doing initial setup to see that it was functional. Setup was pretty easy. I'll test it within the next week and give my opinions on it. The biggest problem I've had with both the ShutterBeam and Time Machine is sensitivity to ambient light. Obviously, this won't apply to night shots or shots in consistent lighting (in shaded areas for example). But for setups in full sun, I found that as the sun rose and moved across the sky it would significantly affect the beam sensitivity-- and the beam would sometimes either start triggering spontaneously with no subject around or not trigger at all when the subject broke the beam. Bill Forbes said that he had these same problems with his earlier models, but that it wasn't a problem with his newest models.

I tested my new PhotoTrap on a Bluebird nest and was impressed with its performance. I used only the Reflect mode in the field and found it to have esentially the same level of responsiveness as the other beam trippers I've recently owned (the ShutterBeam and the Time Machine). Photographing around nesting birds, it is essential to be able to set up the beam tripper fast so as to minimize time at the nest. Because you don't need to use reflectors, the PhotoTrap results in less apparatus at the nest and is much easier/quicker to set up and make beam adjustments . It is also much less prone to spontaneous triggers from changing levels of ambient light.
My biggest problems with my other beam trippers, and the reason I decided to purchase the PhotoTrap, has been time consuming beam set-up and adjustments and the tendency to have spontaneous triggers in full sun (as the sun changed position in the sky).
At home I tested system delay time between trigger event and firing of camera (with mounted flash) and found that the ShutterBeam was fastest, with Time Machine and PhotoTrap (in reflect mode) not far behind. I photographed a dropped golf ball down along a yardstick and used the law of gravity and distance traveled to calculate system delay (Thanks to Steve Yanke –maker of the ShutterBeam for providing the methodology). Again, as noted above, in practical field use, I couldn’t see a difference.

However, when I tried to test the PhotoTrap in Direct Mode (with a reflector), I found the system much less responsive. It would not even trigger on a falling golf ball. According to Bill Forbes, the system is inherently less responsive in Direct Mode and will need an object larger than a golf ball to cause triggering --- he is sending some adapters to me to narrow the beam width. I will try these out when I get them.

So which system do I recommend? It’s too early for me to make a fair evaluation of the PhotoTrap. When I purchased the Time Machine, I found that there was a definite learning curve in how to get the system to function best. I do know that the advantages of working without a reflector are tremendous in the type of photography that I do—so I know that I will use the PhotoTrap often. The Time Machine has an impressive number of additional features that may weigh in your own personal decision, but I have not yet used them myself. Although I think some features are potentially very useful.
You can check out the features of the Time Machine at
http://www.bmumford.com/photo/camctlr.html
I also found Bill Forbes very helpful in answering any questions I had about the PhotoTrap.

Attached is one of the photos (full frame) taken with the PhotoTrap and a custom made Olsen flash unit with 4 flash heads.

If it struggled in direct mode with a golf ball, do you think it would be possible to adapt and use for insects? I was thinking of trying to set up something with an IR laser.

Ed, to give us an idea of time delay... where did you position the beam at the shot of the Bluebird. Right off the nest hole, near the tail of the bird... ??

Great photo btw.

Thanks for the information, Ed. Great shot, BTW.

jn

I've known Bill Forbes for a few years now and own and have been playing with the phototrap for some time. When the phototrap is connected to the camera it leaves the meter on 100% of the time this eliminates any startup delay do to the camera waking up. Also, the delay in triggering is so small it will not effect what you are trying to capture. I have been using it to capture hummingbirds and I never missed a shot because of any trigger delay. Because the beam seems to work best in reflective mode I set emitter below the hummingbird feeder and the detector off to the right and above the emitter. When the bird breaks the beam it will instantly fire the camera. By moving the emitter in or out you can determine where your exact trigger point is. In other words, do you want the trigger to fire as long as the bird is at the feeder? Do you want the trigger to fire when the bird is on approach? And so on. Here are a few from my set up.

For the bluebird shot, the beam was positioned at approximately the end of the tail. You want to position it as close to the nest hole as possible, but not so close that a bird poking his/her head out the nest hole will trigger the camera. You also don't want the bird's tail to trigger it as he leans forward to enter the nest to feed the young. The calculated trigger delay (average of 5 dropped golf balls) for each system (Beam tripper and D2X with flash) was 43 millisec for the ShutterBeam, 48 millisec for the Time Machine and 51 millisec for the PhotoTrap.
As far as how well the PhotoTrap will work for insects, I'll have to wait until I get the beam narrowing adapters and see how small an object will trigger. Maybe Joe McDonald will elaborate on how well it works for insects for him. I do know that Bill Forbes is working on other sensors that are specifically targeted for photography of insects, but they'll be an additional cost.
I don't think hummingbirds are the best test for a beam tripper. Usually the hummingbird is not moving that fast as he appraches the feeder or flower. It is different situation altogether with a bird flying to and from a nest or feeder at greater speed.

Photographers need to be aware of the delay or lag time of the triggering system they are using or planning to use. As Ed has shown above the lag times of the three systems have a spread of
8 milliseconds used with the Nikon D2x. Approxiamatly 97% of this lag time is the camera opening
the shutter. This lag time can vary by make and model of camera and could vary even from shot to
shot in the camera being used depending on settings and hot or cold temperature. These variables would
be measured in milliseconds also. For example, a bird flying through these beams at 20’ per second. The bird is traveling at 2.4 inches per 10 milliseconds, so the bird travels 10.32 inches after going through the
ShutterBeam (43milsec.) and has traveled 12.24 inches past the Phototraps beam ( 51 milisec. ).
I think the ajustment is easily made. I would not think a bird approching a perch or nest hole is traveling
at this speed 4’ from landing site. Even for a head on shot the distance is the same.

The above calculations are based on Ed’s times and my math. False triggering is mostly non- existent
with the Phototrap in any lighting condition. Look at it this way, 50 shots a day of a bird coming or going to a nest hole, 5 frames triggered by something other than the subject, digital???

I try and answer all questions by private message or at phototrap@aol.com.

I posted a question in this thread about the size of the Photo Trap's beam. I revisited the articles on the Photo Trap and saw a hand-drawn illustration showing the "beam". I decided to delete the question but not before the maker of the device saw it. It was an informative response so thought I'd share it here with others interested in the workings of this product.

"My name is Bill Forbes and I am the maker of the photo trap. I saw your question in in the forums about the size of the beams before you changed it to a reply to Ed Erkes comments. So that's why I answered this e-mail of a private message. The size of the beam of the model 33 infrared emitter is around 12 inches at 4 feet and probably 15 feet wide at 20 feet. I'm referring to the brightest area at these distances. The size of the beam at these distances are less important than the brightness of the infrared light emitted. The detector that receives the light from the emitter is key.

The emitter and the detector on the model 33 have a cylinder that is 3/4" in diameter and about an inch and a quarter long. When the light from the emitter is seen by the detector, then the unit is armed and ready to trigger. So these two sensors are pointed at each other at a distance of say 8 feet, although the emitted infrared light may be 7 foot wide, an object passing through the beam needs only block the light going into the 3/4" opening of the cylinder on the the detector to trigger the camera. This would be the point-to-point mode of operation.

The model 33 has this point-to-point mode of operation but also has a reflect mode in which the two sensors are placed together looking in the same direction. The working distance in front of the cylinders is around 4 1/2 feet. When the subject passes through the beam infrared light is reflected back to the detector trigger the camera. There is no reflector necessary in this mode of operation. This is the perfect way to set up for birds, owls coming to a nest box or nest hole in a tree. You can point it from any direction across the path of the subject coming to the hole as long as there is eight or 9 feet clear in front of the cylinders.

Hope this answers your previous question."