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Nikon D7100 System Build

Posted: Mon Dec 20, 2021 1:41 pm
by FarmerDan
This camtrap build is in progress:
  • Camtraptions PIR
    Camtraptions wireless transmitters and receivers.
    Nikon D7100 camera
    Nikon AF-S DX Nikkor 35mm f/1.8G lens (Sigma 50mm macro 1:2.8 DG lens also fits)
    Apache 1800 case (Harbor Freight)
    Nikon strobes: 1 SB-800 and 2 SB-28's
    Bunker Hill 0.30 cal. ammo boxes (Harbor Freight)
    3-inch ABS pipe coupler = lens “tube”
    82mm UV filter
    Pololu Adjustable 4-12V Step-Up/Step-Down Voltage Regulator S18V20ALV set at 7.5v
    12v sealed lead-acid battery (12v Lithium Phosphate is better choice)
    Nikon SD-8 battery pack (3)
    RAM B-sized ball mount
The coupler, was cut down to fit the camera lens and provide a hood for the lens. A piece of ABS pipe is fitted and glued, using ABS cement inside one end of the coupler to strengthen the screws that hold it to the case. The outer side of the coupler is fitted with a UV filter, attached with Marine Goop, a type of glue, to the inner ridge of the coupler. The unit is also secured with epoxy and sealed with Marine Goop. Because the Nikon D7100 does not have a hibernation feature, the camera is powered by a 12v sealed lead-acid battery regulated at 7.5v

Pic below is how the camera and main flash are attached. The SB-800 is in the ammo case and connected to the camera by an off-camera cable. The inset shows the same diameter hole as the flash cord, drilled at the junction of of the two halves of the case, a little offset to the top half to help keep out water. The photo also shows a RAM ball mount for securing the camera to an external mount.
D7100 Fig 1.jpg

3-inch ABS coupler cut to size. Note inner ring where a UV 82mm filter will be glued. A short piece of 3-inch ABS pipe is glued to the inside of the coupler to increase the area where it is attached to the case (inset).
D7100 Fig 2.JPG

The voltage regulator was lightly glued to the case. The power cable is connected to the dummy battery of the Nikon D7100. White paint is to make it easier to align power cable to camera adapter.
D7100 Fig 3.jpg

Power Adapter (dummy battery) for Nikon D7100.
D7100 Fig 4.jpg

Inside of case with all components connected. It crowded but everything fits. Inset shows power for the receiver (signal from PIR) composed of two 1.2v NIMH D-cells and a dummy battery pair in the receiver battery compartment. This is overkill and the receiver power will outlast the camera, but I had D-cells so decided to use them.
D7100 Fig 5.jpg

The ammo case with a Nikon flash and a window of clear acrylic plastic glued to the case. The thread adapter takes standard 1/4-inch bolts. This can be fastened to a tripod ball mount or a stake. The L-shaped metal is standard stock bent to shape. It is for attaching the flash unit to a post or tree via a lag screw or bolt.
D7100 Fig 6.jpg

Inside view of flash case of the wired SB-800 flash and a Camtraptions transmitter that controls the two wireless receivers for the SB-28's. Battery pack for the Nikon strobe contains 6 AA batteries (7.2-9v depending on battery type). It is not a simple power booster: It has three pins and an electronics board that sends power only to the strobe. The 4 AA internal batteries of the strobe only power the flash's internal housekeeping when the SD-8 is attached.
D7100 Fig 7.jpg

View on inside of ammo can housing SB-28 strobe.
D7100 Fig 8.jpg

SD-8 power adapter.
D7100 build Fig 9a .JPG

Front of Unit. Painting wasn't finished and camera is not centered but that is a matter of a little foam here and there. Yes, the lens filter is dirty.
D7100 Fig 9.jpg

These stakes are used to mount the flash units if they are not attached to a tree using a lag bolt or a tripod where soil is not deep enough to hold stakes. The metal stakes are made for securing concrete forms and come in various lengths, usually up to 48 inches. They have holes for nails, though a second hole is needed to securely attach the corner brace to the stake. The ball-mount unit (inset) should be positioned lower than the ones pictured so that it is easier to drive the stake into the ground without hitting the ball mount.
D7100 Fig 10.jpg

Re: Nikon D7100 System Build

Posted: Tue Dec 21, 2021 8:19 pm
by -jeff
Looks good. Looking forward to the results. Also, the D7100 has a great sleep mode. It's set in the camera menu. I think it's called standby time or something like that.

Re: Nikon D7100 System Build

Posted: Tue Dec 21, 2021 9:57 pm
by ghosthunters
Unique built. Can’t wait to see some photos from your build. Good job.

Sent from my iPhone using Tapatalk

Re: Nikon D7100 System Build

Posted: Wed Dec 22, 2021 4:52 pm
by FarmerDan
I checked the camera and couldn't find a sleep mode. You can set the exposure meter, screen, and remote shutter timer to turn off after after a few seconds, but these features alone or together do not put the camera to sleep wiith current draw reduced to a minimum, unlike hibernation/sleep of strobe lights. The voltage regulator, draws some small amount of power, but it's step- up feature means that it can power the camera at 7.5v until the12v battery has dropped to 3-4 volts, maintaining the camera longer. I want to leave the camera and flashes unattended for 4-5 weeks or more. I have not deployed this setup yet, but I expect the flashes will be the first to run out power depending on the number of night photos.

Re: Nikon D7100 System Build

Posted: Wed Dec 22, 2021 9:27 pm
by -jeff
Here is a screen shot of the D7100 manual with the location of the sleep settings.


I typically set the sleep to 4 or 6 seconds and turn off the focus assist light and image review to save battery.

Re: Nikon D7100 System Build

Posted: Wed Dec 22, 2021 10:06 pm
by FarmerDan
Thank you. I see what you were referring to now. I think that just puts the exposure meter asleep until the shutter button is depressed halfway. At least that's how I interpret it. This feature and the monitor and remote timer turn-offs have been present in the D80 and D90, but I was disappointed in the short amount of time in the field they could operate before the battery was exhausted compared to what others have reported for comparable cameras of other brands. Maybe that is wrong or maybe I had too many photos of moving vegetation and shadows. I set all these features to the minimum, turn screen brightness to its lowest settings, use manual forcus and turn off focus assist, preflash illumination, and the LED screen light. It would be better if the monitor could be turned off instead of displaying the image for 4 seconds or more. The D7100 is new to me so I'm testing it indoors to see now long the regular battery lasts.

Re: Nikon D7100 System Build

Posted: Fri Dec 24, 2021 8:10 am
by RichardB
The D7100 (as all Nikons) should last ages when properly set up. Basically, these DSLRs don’t really need to be physically switched off even in non-trap use. In my experience it’s the last thing in trap setups to run out of juice. Should also easily do hundreds of image captures.

It should also be able to switch off ‘Image Review’ in the playback menu to stop any image display.

Re: Nikon D7100 System Build

Posted: Mon Jan 10, 2022 11:42 am
by FarmerDan
Thanks to all who commented. I've been testing the duration of on-time for the regular D7100 battery. It seems to last for several weeks without taking any photos, so the set up with an external 12v battery may not be needed when checked every week or two. My D90 did not last for a week on its internal battery, but again, that may be because of the large number of phantom photos (shadow and vegetation movements in the wind). As a final test, I going to set up the complete system in an unheated room in the shop which I periodically enter, to see with components runs out of power first. I have 6 commercial trail cams set around the property to locate a place that has activity by several species. One spot has recorded 6 species of carnivores, 7 if feral cats are included, plus four species of herbivores.