Z8 as camera trap - autofocus question

[SFShooter]

For the past couple of weeks, we've been blessed with a family of grey foxes (2 adults + 3 kits) who have used our property as a highway. In addition to our home security cameras and a Bushnell trail cam, I decided to try a homemade camera trap setup. It's built around an inexpensive motion sensitive security light, a relay, and a remote trigger cord.



At first I used a Z6II. During the day, it did ok, but at night, it missed focus most of the time. So I switched to a Z8, and the hit rate got much better, but often it still misses completely, most often at night. Perhaps the strong pattern of the gate in the back grabs the attention of the focus algorithm? Do the white LEDs mess with the focusing? The camera is set to 1/500s, f4, auto ISO, which sometimes goes over ISO 20,000. Using the 24-70/f4

The camera is set to AF-C, Auto-area, Auto subject. I just set subject to Animal to see what happens tonight. I have noticed that the foxes tend to squint when the lights come on, so maybe that messes with the focus. I haven't tried flash yet.

Any suggestions to improve focus accuracy would be most appreciated!


This is an example of good focus. That's half a hare in its mouth., and the hare's blood on its front paws. The head of the hare showed up later.


A more common example of back focus.

 

[PLShutterbug]

Read up on auto-capture for your Z8. It will do what you need, by having the camera sense when the foxes appear in a specific part of the frame. It will autofocus, I think, on the animal that enters the capture area and it will take the pictures for you.

 

[commiebiker]

Read up on auto-capture for your Z8. It will do what you need, by having the camera sense when the foxes appear in a specific part of the frame. It will autofocus, I think, on the animal that enters the capture area and it will take the pictures for you.

I do camera trapping out in the field with old DSLRs and flash units. I use manual focus with wider focal lengths and smaller apertures for depth of field.



It's a lot of fun, hope you get some good ones!

 

[PLShutterbug]

Read up on auto-capture for your Z8. It will do what you need, by having the camera sense when the foxes appear in a specific part of the frame. It will autofocus, I think, on the animal that enters the capture area and it will take the pictures for you.

I do camera trapping out in the field with old DSLRs and flash units. I use manual focus with wider focal lengths and smaller apertures for depth of field.

It's a lot of fun, hope you get some good ones!

Nice shots, but I’m not the OP.

 

[Hooligans Imagery]

You have Autocapture in your Z8.

The Guide for AC is under the Z9.

It's tricky. I use it all the time.

The lighting is a challenge. If you are going to use it, bounce it off something.

AC will let you set motion, animal detection (not bird -but you don't want that) and distance.

I would use motion. I would start with Auto-Area AF, with SD for animal. I would use the Target Area feature to eliminate the gate etc.

Start here.

I have used AC quite a bit and happy too help.









--
Thanks for your help, Michael

 

[SFShooter]

Thank you for the suggestions! I did start to read the Z9 reference manual about AC.

I can see how it could negate the need for a PIR sensor during daylight. What about at night, when the foxes are most active? Do I need to leave a light on so the camera sensor has enough of an image to determine the animal's presence?

 

[Hooligans Imagery]

Thank you for the suggestions! I did start to read the Z9 reference manual about AC.

I can see how it could negate the need for a PIR sensor during daylight. What about at night, when the foxes are most active? Do I need to leave a light on so the camera sensor has enough of an image to determine the animal's presence?

Lots of experimenting for you. I was thinking if you have a PIR for the light to go on there is plenty to trigger the camera?

 

[Richard B99]

Thank you for the suggestions! I did start to read the Z9 reference manual about AC.

I can see how it could negate the need for a PIR sensor during daylight. What about at night, when the foxes are most active? Do I need to leave a light on so the camera sensor has enough of an image to determine the animal's presence?

Few years back I photographed (red) foxes using IR only light (speedlights with an IR pass filter over the head) and a D7200 with the IR (cut) filter removed. I did this because the urban foxes in my garden were so skittish that they wouln’t return when flashed once. With IR illumination it wasn’t an issue. As with most camera trapping I manually prefocussed and used a trigger to fire the shutter and lights. My main issue was getting the focus right as IR has a longer than visible wavelength and it took a few nights to get there focus right. Eventually, I focussed at night using an IR torch rather than setting it all up in daylight!

Anyway, if you are interested, my blog:

Now, this is what I was after... - Blog - Richard Boreham (Wildlife) Photography - Now, this is what I was after...

Richard Boreham Photography: The Blog, musings on wildlife experiences and wildlife photography.

www.richardboreham.photography

 

[dspoel]

Apparently the new Z8 firmware lets you set a focus limits in software, such that you can make sure the fence in the back is always way out of focus.
Around 10 minutes in in this video

 

[SFShooter]

Here's a daytime result with Auto Capture. Sometimes, the Z8 still focuses a bit behind the eyes, but the yield is pretty good. I have to keep experimenting with night captures, though.

 

[Hooligans Imagery]

Here's a daytime result with Auto Capture. Sometimes, the Z8 still focuses a bit behind the eyes, but the yield is pretty good. I have to keep experimenting with night captures, though.

Nice capture!

There is no doubt that with moving subjects it won't be on the eyes 100% so high frame rate is fine. What settings did you use? Just curious as I use it a lot so every conversation helps.

On my fountain I can end up with 10,000 images in a few hours. I have a process for finding the good ones using Fast Raw Viewer. I set it up like LR plus with a macro to allow the scroll wheel to fly through them kinda like a movie. FRV has a feature to show edges and detail so when I see some with the composition I like, I check that and mark them with a 4. Those then get sent to a folder for import to LRC.

 

[SFShooter]

I figure foxes are not as fast-moving as birds, so I'm only shooting at 5 fps. Shutter priority, 1/1000 s, f4, auto ISO. I'll follow up on FRV, though.

AC settings are:

Detection: animai, size 1

Distance: 1m to 4m

Area: speed 1, size 1

Record time: 5s, Wait 0s

For some reason, the camera failed to detect 2 foxes seen by other cameras today. Last night's experiment of leaving the porch lights on to help Auto Capture also failed (flash attached). So experimentation continues...

 

[Hooligans Imagery]

I figure foxes are not as fast-moving as birds, so I'm only shooting at 5 fps. Shutter priority, 1/1000 s, f4, auto ISO. I'll follow up on FRV, though.

AC settings are:

Detection: animai, size 1

Distance: 1m to 4m

Area: speed 1, size 1

Record time: 5s, Wait 0s

For some reason, the camera failed to detect 2 foxes seen by other cameras today. Last night's experiment of leaving the porch lights on to help Auto Capture also failed (flash attached). So experimentation continues...

I will study this tomorrow. You may have too many conditions. AC needs them all to trigger. lots of gotchas with AC. Maybe try SD only for your case .

 

[Hooligans Imagery]

I figure foxes are not as fast-moving as birds, so I'm only shooting at 5 fps. Shutter priority, 1/1000 s, f4, auto ISO. I'll follow up on FRV, though.

AC settings are:

Detection: animai, size 1

Distance: 1m to 4m

Area: speed 1, size 1

Record time: 5s, Wait 0s

For some reason, the camera failed to detect 2 foxes seen by other cameras today. Last night's experiment of leaving the porch lights on to help Auto Capture also failed (flash attached). So experimentation continues...

I think you meant Motion and not Area for Speed 1 and size 1.

What can you discern from the foxes position that was captured by the other two cameras and why they may have captured them.

You might want to give Auto Area AF a try with subject detection and then define the Target Area to exclude areas you don't want to trigger. With my fountain this works really good as I can exclude the running water which can trigger subject detection. For this test leave motion out of it. Let the subject detection work and maybe set it to size 2.

 

[SFShooter]

OK, new learnings:

1. Removing the Motion criterion led to more captures. Lots of empty frames, but fewer missed opportunities
2. Using a flash at night didn't work. I attached a Godox V860II, and the refresh rate was not fast enough with the internal battery. Also, the pre-flash caused the foxes to squint anyway.
3. The best solution so far is to use continuous red lights on my porch. It's enough light for AF and AC, but the foxes kept their eyes wide open. I don't have IR lights or an IR-modified camera, but that's the next obvious step.
   
   
   
   
   
   

 

[Richard B99]

OK, new learnings:

1. Removing the Motion criterion led to more captures. Lots of empty frames, but fewer missed opportunities
2. Using a flash at night didn't work. I attached a Godox V860II, and the refresh rate was not fast enough with the internal battery. Also, the pre-flash caused the foxes to squint anyway.
3. The best solution so far is to use continuous red lights on my porch. It's enough light for AF and AC, but the foxes kept their eyes wide open. I don't have IR lights or an IR-modified camera, but that's the next obvious step.
   
   
   

A couple of very nice pics. Just takes a bit of trial and error doesn’t it

 

[SFShooter]

A further update: frustrated.

After suspecting that the Z8 was missing a lot of shots, I decided to place my Bushnell Core S-4K No-Glow Trail Camera right next to it, and left them last night. Indeed, of the 9 incidents that the Bushnell camera captured, the Z8 with Auto Capture caught only one. It literally did not record any images for 8 fox passings.

Here's a still frame from a typical Bushnell video:


Bushnell still frame.

The one passing the Z8 did capture was ok, but focus was missed on many of the frames.




Z8 crop

To review the current settings:

1. Motion capture: off
2. Subject capture: auto, size 1
3. Focus zone 0.8 to 4.0 meters

How else to increase the sensitivity? The only thing I can think of is to add more red light, but that risks causing the foxes to squint again.

Thanks for your help!

 

[Hooligans Imagery]

A further update: frustrated.

After suspecting that the Z8 was missing a lot of shots, I decided to place my Bushnell Core S-4K No-Glow Trail Camera right next to it, and left them last night. Indeed, of the 9 incidents that the Bushnell camera captured, the Z8 with Auto Capture caught only one. It literally did not record any images for 8 fox passings.

Here's a still frame from a typical Bushnell video:

The one passing the Z8 did capture was ok, but focus was missed on many of the frames.

To review the current settings:

1. Motion capture: off
2. Subject capture: auto, size 1
3. Focus zone 0.8 to 4.0 meters

How else to increase the sensitivity? The only thing I can think of is to add more red light, but that risks causing the foxes to squint again.

Thanks for your help!

I mentioned it's complicated; size 1 is too large for the camera being that close. Try size 5 to start. You don't seem to have interlopers.

Also focus will be an issue in the dark and that is a hard one. Can you add light from above?

 

[SFShooter]

After a brief (but marvelous) break in the Eastern Sierra, I tried a couple of new things:

1. Added one more red flood light - this improved the exposure (lowered auto ISO) a bit
2. Set Standby Timer to "No Limit" - this seems to have helped with increasing the incidences captured. Perhaps my prior low yield as simply due to the camera timing out.

Some additional observations:

1. Auto Capture, set to Animal, does not capture the foxes as they walk away from the camera. This is ok, since I want their faces and eyes in the image anyway.
2. The camera still tends to focus behind the eyes. Sometimes the foxes are running pretty fast, but usually they're just trotting along.

We'll see what the next week brings. Last night's examples:




Good focus on the fur on the torso.




A profile view, so focus similar on eyes as well as torso.




Poor bunny.

 

[Hooligans Imagery]

After a brief (but marvelous) break in the Eastern Sierra, I tried a couple of new things:

1. Added one more red flood light - this improved the exposure (lowered auto ISO) a bit
2. Set Standby Timer to "No Limit" - this seems to have helped with increasing the incidences captured. Perhaps my prior low yield as simply due to the camera timing out.

Some additional observations:

1. Auto Capture, set to Animal, does not capture the foxes as they walk away from the camera. This is ok, since I want their faces and eyes in the image anyway.
2. The camera still tends to focus behind the eyes. Sometimes the foxes are running pretty fast, but usually they're just trotting along.

We'll see what the next week brings. Last night's examples:


Good focus on the fur on the torso.


A profile view, so focus similar on eyes as well as torso.


Poor bunny.

think you are doing well my friend; it’s complicated and you are sticking with it.

--
Thanks for your help, Michael