Making the mistake of allowing two variables, I also used a new diffusion setup, placing the small seed inside a translucent 35 mm film container and lighting with LEDs (two Janso, one Tron). The result was terrible flare, a trash image.
Influenced by some really nice work that Saul did with a setup that, as I understand it, included an iris diaphragm between his objective and transfer lens but personally lacking a diaphragm, I made one out of the flocked paper and cut an approximately 20mm central hole (in retrospect, probably too large) hole centrally, mounting it on the Rayox. No joy there; if anything it looked worse.
Moving back to more conventional diffusion (plastic dental cups for the third shot and a sectioned ping pong ball for fourth, specimen on black surface) produced better images; some vignetting with my Nikon 810 sensor, but back in the ball park. My diy aperture was still in, probably not doing anything.
So, to the question: ChrisR has mentioned using an adjustable aperture, but placing it on the "subject side" of the aperture. Is there a reason to have an aperture between the objective and the transfer lens, and if so, how would it be set so as to not increase diffraction? If not, would there be theoretical benefit to a small flocked paper aperture, perhaps incorporated into my diy flocked paper "lens shade" which I used on all these trials?
The two images are submitted without any(needed) adjustment.
Film cannister diffuser
Ping Pong ball diffuser
