Macro Photography experimenting

Macro Photography experimenting (after many years) by Larry Luebbert

Stephen's snowflake pictures got me interested in trying macro now that I have a good digital body that will work with my Nikon pb-6 bellows unit.  Last significant use was duping slides for the 2003 N4C convention with Wilford's fantastic help via the associated copying attachment.  If you can find one (!!!) it would be at least $250.  Bought in early 90's in a KC photography show for $125 with a 45mm GN f/2.8 lens included.  Since it was no longer snowing, I grabbed some common household items - printed paper.  Background  - worked for Hallmark Cards in Kansas City from 1974 until 1993, when I came to Iowa.  Most of my direct printing experience was a large special project that involved modifying a multi-million dollar, 6 color rotogravure press for a metalized film transfer process that Hallmark was developing and later sold licenses to the patent.  A big cost advantage versus metalizing the paper or board directly in an enormous vacuum metallizer.   

All of these were shot with my Nikon D850 at 1,000 ASA and whatever shutter speed needed, the files will not show the correct lens or f stop but will show the shutter speed.  Obviously focusing is a challenge.  The picture of my setup shows a 12mm extension tube between the camera body and the pb-6, found later that the locking ring rotated to allow this body to mount without interfering with the back base so the back extension was not needed.  Lenses are reversed mounted via a br-2 - macro adapter ring.  This could also be used with extension tubes for reverse mounting a lens with fixed extension amounts.  Suspect something similar was available for Canon, not as sure about a good bellows unit.  Unfortunately, a lot of the new lenses do not have a manual f-stop capability so reverse mounting will only shoot at full open aperture.  I have an old Nikon book from the 90's that has a full page of lens magnifications and working distances for use with this bellows unit.  Although this is for Nikon lenses the optical rules are a function of lens focal length so this table would be fairly accurate for other brands of lenses. 

Test images (if the lighting was stronger would have shot these at f/8 or 11):

Halftone Flexographic Printing - 55mm f/3.5 macro @ f/5.6, approx. 100mm extension, around 1.7-2X magnification; discussing this evolving printing process while at Hallmark was almost grounds for dismissal as it was really poor quality in its early days.  Reverse mounting this lens increases magnification by 1X for the same extension.

Lithographic printing (half tone) - common printing method - 55mm macro @ f/5.6 at approx. 100mm extension.  On a general note - this is similar to how now the RGB pixels in a digital sensor are laid next to each other, except there are two green pixels for every 1 blue and 1  red.  Not sure if they're in a "screen pattern" like lithography, however.  Litho inks are very thick, greasy texture and dry very slowly so overlaying one color over another gets a bit complex.  Source: Hallmark Cards Valentines Day flyer.

Lithographic printing - higher magnification - 24mm f/2.8, reversed mounted @ f/5.6 at approximately 70mm extension, magnification around 5.5X, working distance approx. 2 inches; this shows the advantage of reverse mounting shorter FL lenses..        

Rotogravure printing (rotary intaglio) - 55mm f/3.5 macro @ f/5.6, approx. 100mm extension, approx. 1.7X.  This is also halftone printing, but at a much higher quality, back cover of Feb, 2023 National Geographic Magazine.  This process regularly ran at 1,200 - 1,500 feet per minute with rolls of paper as large as 50,000 feet.  Gravure inks were historically Nitrocellulose based with each color drying via an oven before the next is applied, now they are water based.

Rotogravure printing_2 - 35mm f/2.0 reverse mounted @ f/5.6, approx. 55mm extension, about 3.0-3.2 X

Rotogravure printing_3 - 24mm f/2.8 - reverse mounted @ f/5.6, approx. 70mm extension, again about 5.5X magnification