Best Digital Camera With Manual Focus Macro? (1 Viewer)

[Jay Taylor]

Hey Sam,

It took me a while to realize that the lady in the first picture in your first link had eyes! :wink:

Jay

 

[Citizen87645]

I guess I'm so accustomed to looking at my own eyes under normal lighting (my eye color is so dark brown it's almost black) that it's surprising to me how much STUFF there is in the iris. Is there a name for the fibrous tissue in the iris?

 

[Jay Taylor]

Cameron, they are called Iris Fibers but are actually muscle fibers with the following purpose:

quote:The iris has a ring of muscle fibers around the pupil, which, when contracted, causes the pupil to constrict (become smaller) in bright light. Another set of muscle fibers radiate outward from the pupil, which causes the pupil to dilate (become larger) in dim light or darkness.

Jay

 

[Citizen87645]

Thanks for the info. I'd be curious to see what my iris looks like "up close" and illuminated.

 

[Thomas Newton]

quote:

MF is generally barely useable at all on most non-SLR digicams

A couple of reasons:



1. Vendors generally do not design non-SLR optical viewfinders to serve as focusing aids.



2. LCD screens and EVFs generally have too little resolution to give the eye much aid in focusing. (There is a Minolta camera with a ~1 megapixel EVF, but it is the exception that proves the rule. Most EVFs don't even approach VGA resolution.)



A few digital cameras will magnify the center of the screen if you have manual focusing enabled, in an attempt to work around the resolution problem.

 

[Sam Posten]

quote:The iris has a ring of muscle fibers around the pupil, which, when contracted, causes the pupil to constrict (become smaller) in bright light. Another set of muscle fibers radiate outward from the pupil, which causes the pupil to dilate (become larger) in dim light or darkness.

That's exactly how I thought it worked, fascinating stuff.



Not to be vulgar (Like I said, this stuff is fascinating to me), but in Dave_vega's picture of his wife's eye, it looks like some of the top right fibers have detached and are 'floating' into the pupil, is that 'normal'? Additionally in the lower right there is kind of a 'flake' that looks different from the rest of the iris area... Dave_vega has a similar flake and some cool circular formations in top left.



I should probably run a google search to see what the terms are for what I'm describing. Once I get my DSLR I'll post a pic or two of my own eye for you guys to pick apart =p



Sam

 

[Jay Taylor]

quote:it looks like some of the top right fibers have detached and are 'floating' into the pupil, is that 'normal'?

I could be mistaken but I believe that the fibers you are referring to are actually a reflection of the eyelashes.



The flakes occur in most peoples’ eyes. I’ve been told that people that have been taking prescription drugs (or other drugs) for a long period of time have those flakes scattered throughout the iris. Some people are born with flakes in their eyes.



When the iris is illuminated with multiple lights head on as in link #1 in post #10, or with a ring flash, then normally you don’t see extensive details on the surface like Dave’s picture. When the iris is illuminated at an angle it makes the surface of most irises look like the surface of the moon.