Reverse Mounting a Standard Lens Pt1.
Close up and Macro Photography by Reverse mounting a Standard lens
Equipment Used
1. Full Frame DSLR Canon 5D
As the aperture is to be set manually and not coupled to camera body, select the Av exposure mode and allow cameras computer to select an appropriate aperture value ± Exposure compensation can be applied as required use the Histomation technique*2. A 52mm (male screw ) to EOS adaptor (- cost less than £10)
3. 50mm Standard lens
Two examples of 50mm FD lenses are shown in this case Canon the lower one has a breech lock ring mount where lens is positioned in camera body and ring turned to lock it to the body. The top one is an updated version to ease mounting the lens is located in the body and then turned to lock and locate there is a release button on the lens.
4. FD lens mount to EOS mount converter (- cost in region of £20)
note there are no optics in this mount adaptor so infinity focus is not possible, which is not required for Close UP and Macro Applications it just increases lens extension i.e. it acts as a small extension tube when used between camera body and lens.
In this case it is being used as a means of actuating the aperture selector (because I could not find the modified rear lens cap that I normally use)
Adaptors with optics are available to enable FD lenses to be used on EOS bodies at infinity focus
EOS to 52mm filter thread adaptor.
Adaptor is fitted into camera body in same way as a Lens
Lens can then be screwed on to adaptor via filter thread Aperture Selector and Stop Down levers can be seen.
FD to EOS mount ring used to actuate aperture selector you can see the stop down pin, rotating the outer ring brings the pin up against the stop down leaver stopping down the lens to the pre-selected aperture.
Using Canon 5D body on a tripod
Sensitivity us set at ISO200
Exposure Mode to 'Av'
Self timer is used to minimise movement
Lens FD 50mm ƒ1.4 new series (non breech lock ring)
Reverse mount adaptor 52mm filter thread to EOS
FD to EOS adaptor (no optics) used as stop down actuator ( could not find the modified rear cap normally used)
Camera Lens assembly moved to bring subject into sharp focus
Subject Field width 41mm = mag ratio of 1:1.139 or 0.88x
Subject to sensor distance = 18cm
Lens to subject distance = 9cm
Test Results
Full Frame images no cropping
ISO 200 ƒ1.4 @ 1/100s
ISO 200 ƒ22 @ 0.8s
*
Use the Histomation Technique to check exposure if using a Digital SLR, i.e. set display to show Exposure Histogram and check the shape and position of values if using RAW files you should be able to restore a stop or so of highlight values that appear to be over exposed ie at the RH end of the Histogram the display similar to jpeg not RAW values.