[Rockhounds] achieving depth of field w digicam?

Thu Apr 17 07:05:55 PDT 2008

Knowing that we do it knee-deep in blood and guts without the math and STILL
get good pics must be deeply frustrating for the experts ;-)))

Real micro-photography is where the tough get going, my friend (LOL).
I haven't a clue what I'm doing and why but I get it done and that's what
counts. 

Cheers
Axel

> -----Oorspronkelijk bericht-----
> Van: rockhounds-bounces at lists.drizzle.com 
> [mailto:rockhounds-bounces at lists.drizzle.com] Namens J Bryan Kramer
> Verzonden: donderdag 17 april 2008 14:26
> Aan: Rockhounds at drizzle.com: A mailing list for rock and gem 
> collectors
> Onderwerp: Re: [Rockhounds] achieving depth of field w digicam?
> 
> I don't know Axel, when the optical experts start calculating 
> they usually leave me behind. Especially at that scale.
> 
> BK
> 
> On Thu, Apr 17, 2008 at 9:20 AM, Axel Emmermann 
> <axel.emmermann at pandora.be>
> wrote:
> 
> > Hi Bryan,
> >
> > Thanks for the input, it's very interesting and, frankly, I 
> learned a 
> > thing or two just gancing at it. ;-)))
> >
> > However, I did a quick test and got this result
> > Aperture                       16
> > Sensor Width                   22.2 mm (Canon 400D)
> > Subject Width                  4 mm
> > Circle Of Confusion            0.0178
> > Optical Magnification          5.55 X
> > Depth Of Field                 0.12085045045045044 mm
> >
> > Well, I know for a fact that this is wrong... I do macro a 
> lot and 3 
> > and 4 mm imagewidth is target size for me.
> > When I shoot objects at the above settings I get an DOF of 
> just under 
> > 1 mm as this photo proves:
> > 
> http://flickr.com/photos/22753159@N04/2223234472/in/set-72157603704255
> > 629/ This is at least 5 times more (estimated) than 
> predicted by the 
> > formula.
> > True, I use bellows and reversed lenses... That may affect matters 
> > perhaps?
> >
> > Axel
> >
> >
> > > -----Oorspronkelijk bericht-----
> > > Van: rockhounds-bounces at lists.drizzle.com
> > > [mailto:rockhounds-bounces at lists.drizzle.com] Namens J 
> Bryan Kramer
> > > Verzonden: donderdag 17 april 2008 1:57
> > > Aan: Rockhounds at drizzle.com: A mailing list for rock and gem 
> > > collectors
> > > Onderwerp: Re: [Rockhounds] achieving depth of field w digicam?
> > >
> > > Whoops URL:
> > >
> > > <http://www.robertseber.com/calculators/MacroDOFCalculator.html>
> > >
> > > On Wed, Apr 16, 2008 at 8:56 PM, J Bryan Kramer 
> > > <codeburner at gmail.com>
> > > wrote:
> > >
> > > > Here is a macro DOF calculator, use 22.5 as the sensor 
> width for a 
> > > > Canon crop frame camera like yours. At f/45 on a 30 mm
> > > object the most
> > > > DOF you could get is 5mm and you would suffer loss of
> > > resolution at that f/stop.
> > > > You'd need very bright lights too. At a more reasonable
> > > f/16 you drop
> > > > back to 1.7mm DOF.
> > > >
> > > > BK
> > > >
> > > >
> > > > On Wed, Apr 16, 2008 at 7:59 PM, Kreigh Tomaszewski < 
> > > > Kreigh at tomaszewski.net> wrote:
> > > >
> > > > > Tim,
> > > > >
> > > > > The classic trick might work. More light and a higher f
> > > stop to get
> > > > > more depth of field.
> > > > >
> > > > > Kreigh
> > > > >
> > > > >
> > > > >
> > > > > Tim Jokela Jr. wrote:
> > > > > >
> > > > > > This one goes out to the digital photography gurus 
> out there.
> > > > > >
> > > > > > I was talking to a buddy last night about 
> macrophotography of 
> > > > > > small
> > > > > fossils,
> > > > > > 1-3cm stuff, and how capturing any depth of field
> > > continues to be
> > > > > > the
> > > > > major
> > > > > > challenge. He suggested three ways of doing it: buy the 
> > > > > > $25,000 camera system made to do the job, take the picture 3
> > > meters away
> > > > > > from the
> > > > > specimen
> > > > > > and blow up the image, or take multiple shots, focusing on 
> > > > > > different
> > > > > areas,
> > > > > > and stitch them together with Helicon, Combine-Z, or
> > > the expensive
> > > > > > new version of PhotoShop.
> > > > > >
> > > > > > All are basically horrible options.
> > > > > >
> > > > > > So, is there anything new and interesting in the world
> > > of digital
> > > > > > photography that's giving depth of field to
> > > macrophotography in a
> > > > > simple,
> > > > > > affordable manner? (My weapon of choice atm is a 
> Canon Digital 
> > > > > > Rebel
> > > > > with a
> > > > > > 50mm macro lens.)
> > > > > >
> > > > > > Many thanks for any info!
> > > > > >
> > > > > > Tim Jokela Jr., tjokela at execulink.com
> > > > > > Business: http://www.element51.com
> > > > > > Pleasure: http://www.ontariominerals.com
> > > > > >
> > > > > > --
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> > > >
> > > >
> > > >
> > > > --
> > > > "Photography, as we all know, is not real at all. It is an
> > > illusion of
> > > > reality with which we create our own private world."
> > > > Arnold Newman
> > > >
> > > >
> > > > J Bryan Kramer
> > > > North Florida, USA
> > > > photos at:
> > > > http://pbase.com/photoburner
> > > >
> > >
> > >
> > >
> > > --
> > > "Photography, as we all know, is not real at all. It is 
> an illusion 
> > > of reality with which we create our own private world."
> > > Arnold Newman
> > >
> > >
> > > J Bryan Kramer
> > > North Florida, USA
> > > photos at:
> > > http://pbase.com/photoburner
> > >
> > >
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> 
> 
> 
> --
> "Photography, as we all know, is not real at all. It is an 
> illusion of reality with which we create our own private world."
> Arnold Newman
> 
> 
> J Bryan Kramer
> North Florida, USA
> photos at:
> http://pbase.com/photoburner
> 
> 
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