35mm-to-Video Lens Adapters
With the introduction of video shooting capabilities on the Nikon D90 and Canon 5DMkII cameras, we decided it was time to add video equipment to our inventory, to be able to provide both photography and videography items to anyone dabbling in both arenas. Naturally, we added a couple of camcorders, video lenses, and some audio equipment. As we thought more about what items would effectively cross the line between still shots and video, the answer was right in front of us: a 35mm-to-video lens adapter, which could be mounted on a range of video cameras and enable the use of many dSLR lenses we already carried.
Why Use an Adapter? Depth of Field is Key
There are several reasons to try an adapter on your video camera. You may simply want to have the option of using a wide variety of lenses (particularly those you couldn’t otherwise mount on your camcorder). A more popular reason, however, is is the unique, filmlike image texture resulting from the adapter’s ground glass and shallow depth of field when paired with the right 35mm lens.
Depth of field (or “DOF”) is one factor that separates videography from cinematography. A shallow depth of field grants greater creative control, allowing you to better emphasize your subject and eliminate any attention from distracting backgrounds. An extremely shallow DOF is difficult to achieve on consumer or prosumer camcorders, given the much smaller 1/4” (approximately 6.4 mm) or 1/3” (8.5mm) CCD or CMOS chips found in most digital video camcorders, as opposed to 35mm sensors (or film) used in top-end cinematography. The smaller sensors require small, short focal length lenses to produce the same field of view as the larger film camera. Small sensors and lenses (which have narrower apertures) lead to a deeper DOF. Widening the film-video gap even further, 35mm lenses typically have wider maximum apertures, which allow for even greater artistic focus control.
Enter the 35mm adapter, which is attached to the stock lens of the camcorder and allows a variety of 35mm camera lenses to be attached to the setup. The playing field of film and video may not be perfectly level, but it’s a giant step closer to it.
How it Works
The 35mm lens adapter focuses an image onto a translucent ground glass screen, similar to the manner in which you would look at an image through a viewfinder. This increases the size of the imaging plane to something more in line with that of a 35mm film camera. The screen is located between an external lens and the camcorder’s primary (or stock) lens, and the camera’s only task is to record what’s being projected onto the screen. The video camera “sees” an image that has the narrow depth of field of the 35mm lens attached to the adapter.
We Know the Pros, What are the Cons?
There are several different types and brands of 35mm adapters: the Brevis35, Redrock M2, and Letus35 are good examples. All have relative advantages and disadvantages, and it’s up to each user to determine which adapter is best for their particular circumstances.
Generally speaking, 35mm lens adapters have several limiting factors, the five most important of which are discussed below:
- Ground glass texture appearing in the image: The texture of the ground glass the camcorder focuses on can show up in the image in some instances. As a result, many adapters are in constant motion when powered on – some spin (such as the Letus Ultimate) while others vibrate (Letus Elite). Both types have their advantages and disadvantages, but the idea is that the movement blurs the ground glass texture so it isn’t seen on film. However, this effect may be reduced when using faster shutter speeds.
- Weight: Between the four primary components (camera body, stock lens, adapter, and 35mm lens), the entire setup can be very heavy and at times awkward. You’ll need a good rod support system to mount to the setup and a tripod to hold everything steady to get the shots you need.
- Flipped Image: All images are projected upside down in filming, but the circuitry flips the image before it’s recorded. However, when using an adapter (and two lenses), the projected image is typically also recorded upside down. You can either rig the camera upside down to film or flip the image in editing. The Letus adapters, however, flip the image right side up in your viewfinder, with a series of mirrors that right the image.
- Setup Time: If you haven’t worked with one before, it may take you a few minutes to put your adapter rig together (it took us a while when we first began carrying the Letus Elite). It may also take some time to adapt to the different feel of both the setup and your images – as noted above, it will be heavy, and your focusing ring will be extended further than normal. If setup time is a factor for events, and you have an extra camcorder, you may want to try having one camera dedicated solely for use with an adapter.
- Light Loss: The addition of an adapter alone will always result in some level of light loss, and some adapters lose more light than others.
The 35mm adapters made by Letus (specifically, the Extreme, Elite, and Ultimate models) are advertised to lose only 0.5 stops of light, which is the lowest light loss of any adapter marketed today (and the reason we chose that brand to stock). However, one thing to keep in mind is that the light loss doesn’t necessarily begin and end with the adapter:
- When the adapter is mounted on a stock lens, that lens has to zoom in to the level necessary to properly line up the image. Zooming in can cause further loss of light on most stock lenses.
- When you add a 35mm lens, even at it’s widest setting, another f-stop or two may be added. So, when it’s all said and done, you could lose 2.5-3 stops of light even with the Letus adapters. Choosing the right lens and having adequate light when filming is imperative to getting the most out of your adapter.
The best lenses to use with a 35mm adapter will be those that allow the most light in (i.e., lenses with wider maximum apertures). Since lens apertures can’t be controlled electronically with the adapter, you’ll either have to 1) set the aperture before you attach the lens (and not change it during filming) or 2) use a lens with manual aperture controls. If you can stand to carry more than one lens, we’d recommend choosing a couple (or more) prime lenses of varying focal lengths. Although zoom lenses will give you more range in one lens, the image quality may not be as sharp; further, most zooms will have smaller maximum apertures, which may require you to work with a supplementary lighting set up.
The Nikon (other than G series) lenses and Zeiss ZF (which are Nikon mount) lenses are the most popular for use with 35 mm adapters. Filmmakers often order a ‘set’ of Zeiss ZF lenses in various focal lengths for use when shooting with an adapter. Minolta manual aperture lenses are also quite popular (and we carry a Minolta plate for the Letus adapters for those who prefer them).
There can be some obstacles that may make you think twice about using an adapter on your camcorder; however, the benefits of greater image quality and creative control via a unique depth of field are tremendous.
If you’re thinking about renting, we recommend you request it to arrive a day or two early so you can get comfortable with the feel of your setup, and learn how to set it up quickly in the manner you prefer. If you have trouble with it, give us a call or an e-mail and we will be happy to help you adapt (pun intended). Your work will pay off when you see your image onscreen. Happy filming!