I just noticed something on some 4x5 chromes that I took at Great Sand Dunes Natl. Park. I polarized the images and shot a clear blue sky and snow-capped peak. I noticed in a few shots that I have a ghost image of the snowy part of the mountain appearing just above the mountain in the blue sky. My guess is, I'm getting a bounce-back image from the extreme light-dark values bouncing off the shiny film surface, hitting the rear lens element, then reflecting back onto the film surface. I'm thinking that, since the film might have a very slight bow in it, the ghost image appeared just above the actual image. If it helps your opinion any, I was shooting Velvia Quickloads in a Fuji QL holder. Why did it happen? Do you agree with my theory? If my theory is correct, why is the ghost image not upside-down? Why didn't it happen on all the images? What can I do to prevent future mishaps like this? Any thoughts? TIA!

-- Todd Caudle (todd@skylinepress.com), October 27, 2000

Answers

I don't believe that any light bouncing off the film and redirected back would result in anything like the image focused on the film. It sounds to me like you are getting some reflectance between glass surfaces toward the front of the lens. I'd be curious to know what lens and filter types you are using.

-- Robert A. Zeichner (info@razeichner.com), October 27, 2000.

I'm using two Schneider Symmar-S lenses, a 135mm and a 210mm. I had ghosting on images using both lenses, but I also had shots with the 135mm without ghosting. Unfortunately, I only got off the one sheet with the 210mm, as the wind didn't want to calm down. The filter was a brand new Cokin P-series linear polarizer. I've used one for years with no problems. Thanks for responding.

-- Todd Caudle (todd@skylinepress.com), October 27, 2000.

It's the filter. It doesn't have an anti-reflection coating. You're probably getting 4%-8% bounceback.

-- Wayne DeWitt (wdewitt@snip.net), October 28, 2000.

BINGO! The slight curvature of the front element would explain why the ghost image is slightly above the real image, and why it's not upside-down, which seems like the case if it was bouncing off a shiny film surface already passed through the lens. Thanks guys!

-- Todd Caudle (todd@skylinepress.com), October 29, 2000.

this recently happened to me. one of the tiny screws on the front of my camera had fallen out (4 screws right under the lens board on my calumet c400). I was accidentally having some pinhole photography going on there!

so I had one perfect crisp image, and a second very light and fuzzy above it. I was using IR film. I was unhappy about that!

-- paul schuster (paul@schusterphoto.com), October 30, 2000.

You don't mention what lens has been used, but I had a ghost image in the shape of a crescent on images made in bright sunshine with a SA 47XL. I had not used the center filter and read later in Schneider literature that such things can appear with a bright light source using the Super-Angulons. The mirrored center filter should have prevented this to happen.

-- Paul Schilliger (pschilliger@smile.ch), October 31, 2000.

Oh! All right, I missed it. Since you used a 135 and 210, this should be something different.

-- Paul Schilliger (pschilliger@smile.ch), October 31, 2000.