Could You Use a 600mm Copal Lens for a 6x17 Camera?

In the world of ultra-wide panoramic photography, most 6x17 shooters gravitate toward wide-angle lenses (72mm to 90mm). However, using a long telephoto lens like a 600mm on a 6x17 format creates a compressed, "letterbox" perspective that is stunning for landscape photography. But can it be done mechanically?

The answer is yes, but only if your camera body and the lens's image circle meet three very specific technical criteria.

1. The Image Circle Requirement

A 6x17cm frame is incredibly long. To cover this format without vignetting (dark corners), a lens needs a massive image circle of at least 180mm.

• Most 600mm lenses designed for Large Format (like the Fujinon-C 600mm f/11 or the Nikkor-T 600mm f/9) are built for 8x10 cameras.
• These lenses typically have image circles ranging from 310mm to 600mm.
• Verdict: Coverage is not the problem; a 600mm Large Format lens will easily cover a 6x17 frame with plenty of room for shifts and tilts.

2. Bellows Extension: The Real Constraint

This is where most 6x17 cameras fail. To focus a standard 600mm lens at infinity, the distance between the lens board and the film plane must be 600mm. If you want to focus on something closer, you need even more extension.

• Dedicated 6x17 Cameras (Fuji GX617, Linhof Technorama): These cameras use fixed lens cones. There is no 600mm cone available because it would be nearly two feet long, making the camera impossible to handle.
• View Camera Bodies (Canham, Shen Hao): If you are using a 6x17 roll film back on a 4x5 or 5x7 view camera, you must ensure your bellows can reach 600mm. Most standard 4x5 cameras stop at 300mm–450mm.
• The Solution: You would likely need a Telephoto Design lens (like the Nikkor-T 600mm), which uses a specific optical formula to allow a 600mm focal length with only about 400mm of actual bellows extension.

3. Copal Shutter Size and Mounting

Large 600mm lenses usually come mounted in a Copal #3 shutter.

• A Copal #3 shutter is much larger and heavier than the standard Copal #0 or #1 used for wide-angle lenses.
• You must ensure your 6x17 lens board is bored for a 65mm hole (Copal 3 standard).
• The weight of a 600mm lens in a Copal 3 shutter can cause "front standard dive" on lighter panoramic cameras, leading to focus errors.

4. Diffraction and Aperture

When shooting with a focal length as long as 600mm on a 6x17 format, depth of field is extremely shallow. You will likely find yourself stopping down to f/45 or f/64 to get the foreground in focus. At these apertures, diffraction begins to soften the image. While 6x17 negatives are large enough to hide some of this, it is a trade-off you must consider compared to the biting sharpness of a 90mm lens.

5. Stability and Wind Resistance

A 6x17 camera with a 600mm lens (and the necessary extension) acts like a giant sail. Even a slight breeze will cause micro-vibrations that destroy the sharpness of the panoramic frame.

• Mandatory: A heavy-duty tripod and potentially a second support arm (long lens support) connecting the front standard to a tripod leg.

Conclusion: Is it Practical?

Using a 600mm Copal lens for 6x17 is possible if you are using a Modular View Camera system with a 6x17 back and a telephoto-design lens. It is generally not possible on dedicated point-and-shoot panoramic cameras like the Fuji or Linhof due to the lack of lens cone support for that focal length.

Technical Summary:

1. Image Circle: Safe (usually >300mm).
2. Shutter: Copal #3 (check lens board compatibility).
3. Extension: Requires ~400mm (Tele-design) or ~600mm (Standard design).
4. Best Use: Compressed mountain ranges or distant architectural details.