Need Help with Zuiko 35mm Macro Lens

[Manuel Sam]

Hi. I currently shoot an E-330 with the standard 14-45mm lens in a 10bar housing (thanks to Jeff Mullins for his Wetpixel report and suggestions).

I have it hooked up to my old Nikonos SB-105 strobe, set at 1/4 power, shooting in Manual and no TTL - that was quite an adventure going from the Nikonos V to Point-and-Shoots in Automatic mode to shooting DSLRs in Manual.

I recently bought the 35mm macro lens - I didn't want to spend too much while I ventured into unchartered (for me) waters so I went with the cheaper lens. I was also swayed by its shorter focal length (5+ inches) vs. 9+ inches on the 50mm - not sure that it's an advantage but, right or wrong, I went with the "closer is better" thought process.

Please pardon my ignorance since my only prior macro experience was with the Nikonos extension tubes and framers.

To test the lens out, I started with just the camera and lens (no strobe) and placed a dime on a dark background. I half-pressed the shutter-release button to focus on the dime. What I found was that depending on how far I held the lens from the dime, the amount that the lens would extend out to one of four different "magnification" settings (1:4, 1:2, 1:1.5 or 1:1) that are marked on the lens barrel would vary.

With the camera held such that the lens was approx. 5.5" from the dime, the lens went to 1:4 when I half-pressed the shutter release button. The resulting image of the dime was rather small.

I then moved the lens progressively closer to the dime and the lens proceeded to extend out further, to 1:2 and then 1:1.5, when I half-pressed the shutter release button. When I finally got it to the 1:1 setting, the dime was filling quite a bit of the screen, and the lens, by my rough estimates, was no more than 1" from the dime.

In all cases the images obtained were decently focused although a bit shaky because lighting wasn't great so my shutter speed was relatively slow, even at ISO400.

Those of you who have used or are using this lens......does this make any sense? I thought that 5+ inches minimum focal length means that you cannot focus closer than that. Besides trial and error, how do you go about shooting something the size of a dime with this lens? Or the size of a half-dollar?

Thanks for your help.

Manuel

 

[PHIL RUDIN]

Hi Manuel,

Perhaps I can help you out. Closest focus for the 35 mm macro is about 5.6 inches. The minimum focusing distance for all cameras is from the film or sensor plain to the subject. The sensor is in the rear of the camera, plus the length of the lens, plus the distance to the subject and you are left with about an inch or two between the outer lens element and the subject. Add a port and it gets worse. To my knowledge Athena is the only company that makes a port just for the 35 macro and it is for the Olympus DSLR housings. If you use a port designed for the 50 macro the port will work fine but because the port is longer to fit the 50 macro the 35 macro comes up short and at those close distances will focus inside the port at 1:1. In other words the lens stops when fully extended an inch or so from the inside of the port glass and you have a problem. If you back off to 1:3 or so you can get the subject in focus.

I use the 35 macro for subjects like fish starting at about six inches or bigger.

The 50 macro at twice the price is by far the better choice because it puts more distance between the port glass and the subject, is an F/2 lens which speeds auto focus, has weather sealing and is laser sharp.

Phil Rudin