Samgold Photography | Portrait Photographer | Orlando, Florida


BCLmacro Part I: Conversion from wide angle gem to macro with a twist

Besides pure magic, ever wonder what is inside that tiny body cap lens (BCL) of yours?? Well.. I was led down the path to find out and along the way I discovered that a simple rearrangement of the internal lens element creates a "pseudo-macro"lens. I have estimated it has a 1:3 magnification ratio which is far from true macro capabilities (hence, "pseudo") and the rendering of images is, to put it nicely... unique. I don't suggest you go out and buy a body cap lens just to hack it up (because there are better alternatives to for cheap macro photography) and even if you already have one that is in working order its probably not worthy of sacrifice (especially if you enjoy using it).. BUT if you have abandoned your BCL, it has been rendered dysfunctional, or you really enjoy the lofi/holgaesque nature of the photos rendered (like I do!) then this may be a fun afternoon project =) I initially dismantled my BCL because during one of my daily photography sessions I noticed that it was excessively blurry around the edges. After cleaning it I saw no improvement, so I decided that since this lens is relatively cheap and easily replaceable that I was going to dismantle it and see if I could fix the problem.. Maybe there was something askew inside that was resulting in burred images??? 

Mysterious excessive blur
After disassembling and reassembling the problem did not correct itself and since I had gotten some pretty good panoramas from it, I figured my $50 was well spent in the time I had used it . I was planning on just tossing it and calling it a loss but then for some odd reason I thought of the technique used by many to turn old legacy glass into a macro lens using a cheap converter. Here the converter flips your lens so that the front elements face the sensor and the "mount end" is exposed to the elements. I thought to myself that the same concept should apply to the BCL, and hell, it was already malfunctioning so no harm in giving it a try! After some experimentation which entailed dismantling and re-arranging SEVERAL times (plus some modifications to the plastic) I finally came up with something that was usable.

In order to accompish this, you will need:
  • Sacrificial body cap lens
  • Tiny screwdriver (small flat head worked best for me)
  • Rounded file or something else to make an existing opening larger (optional)
  • Q-tip for cleaning
  • Midget hands or lots of patience
If you want a rather significant vignette or do not want to lose the ability to protect the lens element then I suggest that you do not disassemble the front lens plate (part that has "OLYMPUS LENS 15mm 1:8.0" on the front). I have experimented with a couple of configurations, but once you modify the plastic via filing there is no turning back so it is best to see the examples below to get an idea of the types of photos each modification produces. All the examples below were taken using the kit flash (varying intensities) at 1/250 with an iso of 200. Raw files were then imported to LR4, re-sized when exported (1000 pixels to cut import time--I am offshore with bad internet), and re-sized using Blogger (X-large). 100% crops of RAW files were not re-sized at any point and no post processing (contrast, sharpness, clarity, etc) has been done on any of the files.

A. Simple lens element reversal without further modification: results in heavy vignette/ small degree of color fringing:

100% center crop

B. Removal of front lens plate completely: results in lighter vignette with the cost of increased color fringing

100% center crop

C. Filed down front lens plate: similar to removal of lens plate (B.), but front of lens looks better

100% center crop

D. Filed down internal platform and complete removal of front lens plate: almost no vignette but edges still exhibit color fringing

100% crop of in-focus area
E. Filed down internal element + filed down lens plate: similar to "C."

100% center crop
If you are interested in this hack disassembling the body cap lens should be your first move. You will end up with (all names made up; from left to right in photo below):
  • Mount, 4 associated screws, 8 tiny golden donuts (2 not pictured, lost)*
  • Internal platform (in picture turned right side up with red dot facing you) + front lens plate, three associated screws and lens cover (2 pieces)
  • Lens element + large spring
  • Lens element holder and three associated screws
  • Small spring (not pictured--lost)
  • Tiny metal ball (not pictured--lost)
* I have no clue what these were for :/

The order you disassemble the BCL is to: Detach mount --> Detach lens element holder --> Detach front lens plate. If you do this, you end up with a bare internal platform. Reassembly is not difficult as the BCL is wonderfully simple, but if you want to reduce the amount of vignette then you need to file down the internal platform (A) and/or the front lens plate (B). I ended up filing less than 1 mm off the internal platform and a little more than 1 mm off the front lens plate. Remember once you do this (and depending on how much you file away), the opening of the front lens plate will become too large to be covered using the sliding cover and you end up with two gaps. So if you still want to be able to close the BCL to protect the lens element then I suggest you do not remove the front lens plate and go with the "heavy vignette" option. Honestly I probably would have done this if I had know better, but once I filed down the opening it was too late. Also if you leave the front lens cover intact then there is no reason to file down the internal platform. The other plus side of not altering the plastic is that you can switch back to wide angle amazing if you get tired of the macro hack.

(A) Bare internal platform and file
(B) Front lens plate and file
After you have filed the internal platform and/or the front lens plate turn the internal platform upside down (red dot down) and place the lens element inside its holder with the small opening facing you (C).

(C) Lens element reversed and placed inside internal platform
Then attach the lens element holder to the internal platform using the three tiny screws provided (D).

(D) Lens element holder attached to internal platform
 If you have taken the front lens plate off for filing then the next step will be to attach it back to the internal platform using another set of three very tiny screws (E)

(E) Front lens plate attached to the internal platform
Finally line up the mount as pictured below (F), attach it to the internal platform using the four larger, but still very small screws and presto! you are done(G)!

(F) Lens mount and internal platform 
(G) Lens mount attached to internal platform

It really is insanely simple... especially if no filing is done. Take the BCL apart, flip the lens element, and put it back together. I ended up not needing either of the springs, the tiny ball,  or the two pieces of plastic that make the lens element cover. If you plan to use the lens cover then do not mess with the tiny spring and ball as these are needed for the lever to function. In this scenario, the only thing you will not use is the large spring. I am planning to write more about the details of how this lens performs in the very near future (probably post tomorrow). I am actually extremely surprised by the BCLmacro's sharpness.

Oh what a world!
The image quality is no where near that which you would get with a dedicated macro lens... it is still the body cap lens after all, BUT if all images were cookie cutter sharp, photography would be an extremely boring art form. I started out a big fan of the BCL (you can find a great collection of images from a variety of people here) and this modification has only added fuel to the flames of my love for this unique lens. If you do decide to try this out I want to state (even though it should be common sense), that I am in no way responsible for you ruining your body cap lens or injuring yourself during any part of this process. As always, innovate at your own risk. To help you decide whether this is something you are interested I will leave you with sample photos which have been processed to taste in LR4. I have created a Flickr group dedicated to this hack and if you are brave enough to convert PLEASE share your photos!!! Thank you for dropping by hope you have an amazing time with this strange (almost) macro =)

Sam D.

**********************************************UPDATE 12/12/2013**********************************************
As an alternative to dismantling your body cap lens, I found you can also use Meike extension tubes with an unmodified body cap lens as a macro alternative. See here for details. The extension tubes can also be used with the BCLmacro:

BCLmacro +10 mm extension tube

BCLmacro Sample Photos:

Some photos look great with the heavy vignette.. especially in B&W

Considering what this is... Bokeh is surprisingly good

If photo is cropped, vignette and color fringing are negligible
P.s. The working distance of the BCLmacro is approximately 7 cm so you have to get in really close. BUT you can effectively use the kit flash to counter the shading you will experience at this proximity.. Also the DOF is about 1 cm so working is magnify mode is your best bet. More on this in tomorrows post.