eframgoldberg Loc: South Florida

Recently has not been the sunniest of weather, so I've been studio working with a paper wasp I found a few days ago.

90 image stack, 0.900mm Depth taken at 0.010mm steps. Nikon D5100 on a Nikon PB-4 bellows, Nikkor 28-mm f/2.8 Ais reverse-mount, set at f/5.6, SB-600 off-camera through a paper diffuser. Everything mounted on a Parker linear stage with Mitutoyo digital micrometer which is bolted onto a granite slab. Set-up photos here: http://www.uglyhedgehog.com/t-32754-2.html#848810 .

Polistes sp. View at Full Resolution.

eframgoldberg Loc: South Florida

I think I fixed the lighting problem

eframgoldberg Loc: South Florida

and finally

infestation Loc: Brampton, Cumbria, UK

Fantastic detail, and amazing dedication, 90 images, maybe in the future, I just can't see myself doing that just yet. A real joy to look at though.

napabob Loc: Napa CA

ah...................WOW

eframgoldberg Loc: South Florida

The 1st shot is 0.900mm depth with 0.010mm steps for 90 shots. the second image is 0.900mm deep with 0.020 steps for about 45 shots. the third image is 3.600mm deep with 0.025mm steps giving about 144 exposures. ALl were taken as jpegs and stacked in Zerene using Pyramid method.

Kimbee Loc: Dunedin, Florida, USA

Amazing!

naturepics43 Loc: Hocking Co. Ohio - USA

Very nice images. Nice setup also.

I've done a little photo stacking and used f16 or f22. Curious why you use f5.6. Is it because of the high
magnifaction and use of bellows?

eframgoldberg Loc: South Florida

By the laws of optical physics, the larger the aperture the more resolution the lens is capable of. This is because of diffraction. Most lenses are not their sharpest wide open however due to other optical aberrations. These aberrations are more apparent when lenses are wide open. Most lenses will reach their maximum resolution at around f/5.6-f/8. You can check resolution charts, MTFs at lens tips or dxo mark but that is the gist of it. The only reason to use f/16 or f/22 is because you need the large depth of field at the expense of sharpness. By these apertures diffraction will definitely be noticed. The whole point of focus stacking is to artificially increase the depth of field. Therefore if I am focus stacking Ill pick f/5.6 or so because depth of field is not an issue and it's right in the "sweet spot" of apertures. When I shoot regular macro I shoot at f/11 because if I stop it down any more I see blur due to diffraction.
Since the lens is on a bellows anyways the F number does not mean too much. It represents the absolute size of the aperture with regards to focal length. Reversing the lens and putting it on a bellows completely screws up the focal length. That's why most optical and lab optics have numerical apertures rather then f stops, it is more a property of the optical system itself, then the focal length chosen.

naturepics43 Loc: Hocking Co. Ohio - USA

Thanks for the thorough explanation. I will try this next time I do a focus stack. Your images have renewed my interest in focus stacking.

eframgoldberg Loc: South Florida

A good experiment is to find a dead insect like a fly or bee or something small that is not going to move. Then take like 3 shots at f5.6, 3 at f8, 3 at f11, 3 at f13 and 3 at f16 and 3 at f/22 and look at them on the computer at 100%. You will start to see the image degrade. Then you will know for your system what the trade offs are for different f stops.

Just to complicate things a little more, Nikon will display the effective aperture of lenses, and Canon will display the actual aperture. This is because modern macro lenses effectively change focal length when zooming to 1:1 and the f stops change. I have not gotten a solid answer as to the question of which f stop value, i.e. actual or effective, is used to calculate depth of field and diffraction.