Shooting Manual

Before taking an RTI image you must decide on which lens to use and if you will be shooting RAW images or JPEGs. Also look into vibration reduction techniques.

Always refer to the online camera manuals for more details.

Note

This guide refers to Nikon brand cameras. The RTI dome works with other brand cameras too. We will add those cameras as soon as we can get our hands around some.

Camera Settings

  1. Turn the camera on. Turn the power switch to ON.

  2. Check the clock of the camera. Press MENU, then select SETUP MENU, Time zone and date, Date and time.

  3. Choose RAW or JPEG. Press QUAL and turn the rear dial until either RAW or FINE★ appears in the display.

  4. Set the white balance to incandescent light if you are shooting JPEG. Press WB and turn the rear dial until a light bulb symbol appears on the camera display. This setting has no effect on RAW images.

  5. Set the camera to manual exposure. Press MODE and turn the rear dial until an M appears in the display.

  6. Set the ISO sensitivity. Use the ISO sensitivity with least noise. Press ISO and turn the rear dial until the chosen value appears on the camera display. All cameras have one ISO sensitivity where the sensor noise is minimal, usually the lowest, but you should check with your camera manual or the internet.

  7. Set the camera to Continuous High Speed Mode press the safety button near the dial and turn the left dial to the CH position.

  8. Set the camera and lens to manual focus. Set the focus-mode selector on the camera to M. Also set the focus mode switch on the lens (if present) to M. 1

  9. D700 only: Turn on exposure delay mode. Press MENU and select CUSTOM SETTINGS MENU, d9.

  10. Turn the camera off. Turn the power switch to OFF.

Dome Setup

  1. Connect the RTI dome to the CRM 114 (Camera to RTI Module) using two Cat.5 or better Ethernet cables. Don’t swap the cables: make sure to connect socket 1 on the CRM 114 with socket 1 on the dome.

  2. Connect the camera to the CRM using two interface cables. Connect the PC-Sync output on the camera with the flash input on the CRM. Connect the trigger input on the camera with the trigger output on the CRM.

  3. Fit the lens and camera to the dome. Align the camera’s vertical axis with the 0° axis of dome. The tripod socket on the camera should be near to the 0° marking on the dome while the bottom plate of the camera should be at exactly 90° angle to that mark. Note: A polarizing filter between dome and lens will allow you to align the camera with more ease.

    Warning

    A correct alignment of dome and camera is essential to RTI.

  4. Optionally connect an external monitor to the camera using a cable with a mini-HDMI plug at one end.

  5. Connect the AC/DC adaptor to the CRM and plug it into a wall socket. The green light on the CRM should come on.

  6. Turn the camera on. Turn the power switch to ON.

Shooting

  1. Put the object under the dome in the approximate center of the dome. You will find the exact position later.

  2. Turn the pilot light on. Short press the green button to turn the pilot lights on. You can also use this button to turn the lights off again.

  3. Focus and center the object. Look through the viewfinder and use the focus ring on the lens to put the object into focus. Move the dome or the object around until the object is in the exact center of the picture. Be careful not to rotate the camera from the 0° position.

    If you want to use live view, press Lv to enter (and exit) live view mode. This will show the picture on the camera monitor. If you have an external monitor attached to the camera you will also see the picture there.

  4. Take a test exposure. Press the shutter-release button to make a test exposure.

    Review the picture and check the histogram. Press ▶ and then press what Nikon calls the multi selector in the down direction until you get to the histogram view. Adjust the lens aperture (front dial) and/or the shutter speed (rear dial) (and maybe also the ISO sensitivity). Repeat this step until you are satisfied with the picture histogram.

  5. Close the viewfinder. This avoids stray light falling into the camera from above.

  6. Turn on live view. Nikon D800 and later models only. Press Lv. The object should now appear on the camera screen.

  7. Long press the green button to start the shooting run. The camera will start taking exposures.

    During a shooting run don’t touch the camera or dome and avoid anything that may cause vibration.

    The red button resets the CRM. Use it to abort a shooting run.

    The shooting run is done when the green light comes on again.

    Remove the object from under the dome, open the camera viewfinder and repeat from step 1.

    Warning

    After every shooting run check all your pictures’ histograms for over- (specular lights) or under-exposure. If unsatisfied adjust the aperture, shutter speed and maybe ISO sensitivity and repeat the shooting run. The pilot light alone does not give you complete guidance to set exposure parameters 2.

Various Notes

Working speed: Your mileage may vary depending on the shutter speed you have to select and on the speed of the memory card in the camera. Cameras have an internal buffer, which fills up after a short burst, after that the speed of the memory card may limit the frame rate. If your exposure time is longer than the writing time the speed of the memory card may not matter.

Choosing the lens aperture: the right lens aperture depends on the depth of field (DOF) you need to bring the whole object in focus. A flat object requires only a small DOF, an object with more relief requires a larger DOF. The smallest aperture gives you the largest DOF. Note that higher numbers mean smaller apertures: f/8 is a smaller aperture than f/4. OTOH at apertures smaller than f/11 lens diffraction will become noticeable.

If you look through the viewfinder you see the DOF of the largest aperture, which is much less than the DOF you will get on the actual picture. Now focus somewhere on the middle ground of the object. If you press the DOF preview Pv button, the lens will stop down and you will see in the viewfinder the actual DOF you’ll get in the picture.

If you want color, place the object onto a grey card or put a color reference chart near the object. This will make it easier to find the correct white balance in the raw converter software.

Footnotes

1

Manual focus mode makes sure the camera does not attempt to focus during a dark interval. You may use autofocus if you configure the camera to focus on a different button than the trigger release button.

2

The pilot light (current shared by N LEDs) has not the same intensity as the individual LED (current used by one LED) because LED emission is not linear with current. Also specular lights will be N times brighter if the object is lighted by one LED only.