Trail cameras in the field, some gotchas

I tend to put my trail cams out in the 'wild'. Basically the nascent reserves of Manor farm and Fleet Hill farm. It was an enormously frustrating experience as I tried to work out why I had so many videos and photos of scenery. Nary an animal in sight.

Various reviews raved about how good these trail cams were and wonderful videos were posted. Did I have dodgey units?, I wondered.  I can believe the possibility of one being naff, but three!?!?  I think not.

Anyway, I did a few experiments in the comfort of my dining room. Coupled with the results of what I actually got, I finally realised what was going on.

Firstly I must point out that I have cheap trail cams. I place them out where members of the public can happen on them. One of my favourite places is along the Blackwater (with attendant fisher folk), fairly close to a bridle path. Whilst most people would, and indeed have, left them alone, some local oik is likely to nick the unit for grins. I would be annoyed at losing the unit, but not half as aggrieved if, for instance, I splashed out over £100 or £200 on them.

The units I have are:

Ltl Acorn: I think about £75 six years ago. Only takes videos with 640x480 resolution.

Victure: £45 January 2018. Not bad, takes photos and reasonable videos of good resolution.

Crenova: £68 April 2018. Takes photos, and much better video than Victure.

I set up the Crenova and Victure in one of two ways

1. Only take three photos
2. Take three photos and then a 20 or 30 second video.

I get the units to take photos as I am almost guaranteed to get whatever critter it was that fired the units. The video is a bonus. If you only take videos, you are almost guaranteed not to get the critter - unless it is slow moving and/or hangs around the camera.

Now the 'gotchas'

Trigger time

The marketing blurb and review sites make great play of this. It is sort of the holy grail to get as low a trigger time as possible, but beware.

This is the time it takes for the unit to detect movement and warm up the electronics to the point where it can do something. Trigger time typically ranges from 0.2 to 0.8 seconds.

I think the Crenova has a trigger time of 0.5 seconds, whilst the Victure has a 0.8 second trigger time.

Time to photo

This is NOT the same as trigger time. Once the unit is warmed up and ready to go, it can then take a photo. Typically this can be 0.2 to 0.5 seconds AFTER trigger time has elapsed.

Think about when you press the shutter release on your camera. There is a fraction of a second before the photo is actually taken, even though your camera is humming away ready to take a photo.

Thus, it can take as much as a second for my Crenova to take a photo, whilst the Victure can take one and a half seconds.

Most marketing blurb or review sites do not mention this. In fairness, Crenova do, sort of, but it is buried deep in the manual.

Time to video

This is NOT the same as trigger time. Once the unit is warmed up and ready to go, it can then think about videoing. I find it can take between one or two seconds before videoing can commence.  That is one or two seconds AFTER the trigger time has elapsed.

The fastest the Crenova has reacted is 1.5 seconds. Typically is takes between 1.5 and 2 seconds from detecting movement to commencing videoing.

The fastest the Victure took was just over 2 seconds. Sometimes it took 3 seconds.

I think the ancient Ltl Acorn was somewhere between the two.

I don't think you should be too surprised the time to photo or video. Think about when you turn your camera on, how long it takes to sort itself out before you can actually press the shutter. OK, the trail cams are in hibernate mode, but even then, think how long it takes, say, your mobile or tablet to get going from this mode.

Again, marketing blurb and review sites do not, from what I have seen, mention this.

SD card speed

This does make difference with time to photo and time to video. Particularly if you get the unit to take photos and videos. Afterall, the images have to be written to the SD card, before another action can take place.

I think I use cheap to middle of the range SD cards i.e. not the cheapest, but the cheaper of the 'known' brands.  Therefore I am afraid I do not have any figures for a top of the range, high performance SD card.

Animal speed

They move quickly, very quickly. The smaller they are, the more they seem to keep moving; erratically and with many changes of direction. If they don't they will either be a meal or not catch a meal.

This means that by the time the trail cam has got to the point where it takes a photo the creature has long gone. This is particularly true if the critter goes across the camera's field of view. I captured many a shot of the tip of a tail.

You shouldn't be surprised with this. Think about a normal walking pace. You can easily cover two or three metres in a second. Also if you have ever had to catch one, think how fast a mouse can run.  As for birds, they zoom across in flight, triggering the camera, which records nothing.

Short night videos.

I haven't got to the bottom of this. The Crenova and Victure are particularly bad at this. Not sure about the Ltl Acorn. The videos last between 2 and 10 seconds, instead of the normal 30 seconds. I can understand it if the critter moved out of shot by the time the cameras commenced videoing. However, it makes no sense when there are three fox cubs and mother playing some 15 metres away.

They are large, and have nice warm bodies. They trigger the cameras, and keep moving, but the cameras quickly stop filming. Weird.

Subjects approaching the trail cam

For some reason, both the Victure and Crenova tend not to be too brilliant at detecting subjects that approach them. Any number of mornings I have walked 30 metres or so toward the units and they have either not detected me or done so at the last moment.

Some of this 'might' be due to it being cool or cold mornings, say between minus three and plus five. I am muffled up in coat, gloves, hat, scarf, etc such that only a tiny part of my face is visible. Perhaps, being so dressed, I am at the same temperature as the surrounds. Who knows.

However, when I set up the trail cam to see if any itinerant cats were using our cat flap, I did notice that the units did not pick cats coming towards them. They were good at picking up cats going away from them.

Sunny weather

This caused me no end of grief. Basically, the unit keeps firing. I normally set the camera to sleep for five seconds and then wake up to see if it detects movement. If there is something interesting I get loads of great photos and videos.

However, when the weather is sunny and warm, and the unit is placed in the sun, it just keeps firing. This fills up SD card and drains battery.

I am not too sure what is causing it. Either the sun beating down on the units causes it to heat up so much internally the electronics go haywire or the sun has heated up the vegetation to the point where it, moving in the breeze, causes the units to fire. A third possibilty is that there are more insects around in sunny weather, and they trigger the units.

I still haven't got to the bottom of this, and I may try and build a cover to shelter the units if I place them in the open, but is it very frustrating. I can get hundreds or thousands of shots of the same empty scene, each spaced at 22 or 32 second intervals.

Battery life

Anything less than about 15% charge and it is best to put new batteries in; especially if you have set the unit up to take videos. It took me a bit of time to work this one out. The units looked fine at home. The charge looked respectable. They downloaded images, allowed me to preview them, but when I put them out into the field they would stop capturing images after a day or three.

It does kind of make sense. Videoing takes a lot of power. Downloading or previewing image with the units does not. Plus the blurb make a point of saying how long the units will work for e.g. 6 months.  This is true, with eight batteries, and only taking photos, and not taking tens or hundreds per day.