One Light Two Set Ups
Left to right, dark field illumination. bright field illumination
The above images are of the same blown bulb from a 800w Redhead incandescent continuous hot light. Ironically I kicked the light stand whilst the light was switched on, after telling a group of students not to move hot lights when they're switched on, as that's when the already delicate filament is even more delicate!
It's possible to achieve this kind of image with almost any flat, soft source of light, either soft box or LED panel. For this this shot I used a Rosco 24" x 24" Litepad as that's what was handy.
The image on the right with the black background I clipped in place a piece of matt black material to provide the back drop. The bulb was lit by the light by the light from either side of the black material, providing transillumination and edge highlights. The width of the highlights can be controlled by the width of the black material.
On the right with the white background I used a piece of LEE Filters 129 Heavy Frost diffusion gel to hide the etched grid of the light and even out the illumination. Here the edges of the bulb were defined by black cards either side, just out of frame. A soft silver reflector was placed just out of frame left to create some shape in the ceramic insulation tips.
As I used a continuous light source metering was pretty simple as I used the camera TTL meter and rode the exposure compensation - for the dark field image I underexposed by 1.33 stops, the bright field image over exposed by 2 stops.
The bulb was positioned on a blob of white tack on a plastic rod, clamped in Super Clamp resting on the bench top. From set-up to finish this whole shoot took 20-30 minutes.
Images were put through my usual ACR processing, the white tack removed and images comped in PS CC.
The camera was fitted with a macro lens and supported on a sturdy solid metal studio stand allowing smooth lateral and vertical camera movement.
If you're serious about your photographic lighting then maybe The LIGHT Side Facebook group https://www.facebook.com/groups/thelightsidegroup/ will interest you. It's about all things to do with light and lighting. TLS is a closed group so someone will need to add you or you'll need to send a request to be added. It's a friendly group, with a degree of humour and some great photographers willing to share and contribute.