Jumping Spider up real close.

Jody Melanson · Post by **Jody Melanson** » Thu Jul 20, 2006 8:09 pm

Canon EOS 1D Mark II N + Sigma 150 + 50/1.8 reversed + 3 Tubes.
1/250s f/20.0 at 150.0mm iso50 with Flash
Handheld.

Also with reversed lens.

Wim van Egmond · Post by **Wim van Egmond** » Fri Jul 21, 2006 2:09 am

Wonderful results! Interesting idea to put a lens on a lens. How does this contraption look?

Wim

Ken Ramos · Post by **Ken Ramos** » Fri Jul 21, 2006 2:42 am

These spiders have some really big and beautiful eyes; I wonder why spiders eyes are not faceted? Anway a really up close and very good shot of the jumpers eyes.

Wim van Egmond · Post by **Wim van Egmond** » Fri Jul 21, 2006 3:01 am

I think a compound eye is less accurate. It gives an overall view but with not much detail. Jumping spiders can actually focus with these eyes! They probably have stereoscopic vision with these front eyes. Ideal for hunting!

Wim

Jody Melanson · Post by **Jody Melanson** » Fri Jul 21, 2006 3:13 am

Wim van Egmond wrote:Wonderful results! Interesting idea to put a lens on a lens. How does this contraption look?

Wim

Thanks Wim. Here is how it looks. I've got 3 extension tubes on, then the Sigma 150, then the 50 reversed up front. The whole thing weighs about 5lbs!

Jody Melanson · Post by **Jody Melanson** » Fri Jul 21, 2006 3:16 am

Ken Ramos wrote:These spiders have some really big and beautiful eyes; I wonder why spiders eyes are not faceted? Anway a really up close and very good shot of the jumpers eyes.

Thanks Ken. I guess like Wim says? When looking at him through the viewfinder, you can see the eyes change. I read that when they are red like one in this pic, it isn't looking at you. When they are black, they are looking at you. He is holding onto an Ant. When he was first grabbing the Ant, most of his eyes went red while he was watching the Ant and not me. Really cool to watch!

Jody Melanson · Post by **Jody Melanson** » Fri Jul 21, 2006 3:17 am

Wim van Egmond wrote:I think a compound eye is less accurate. It gives an overall view but with not much detail. Jumping spiders can actually focus with these eyes! They probably have stereoscopic vision with these front eyes. Ideal for hunting!

Wim

And it appears the eyes are independent of each other like a Chameleon.

Wim van Egmond · Post by **Wim van Egmond** » Fri Jul 21, 2006 3:39 am

Thanks for the picture. I will also try that! I also have that 150 mm sigma. Great lens. Quite heavy though. You need to use a support.

About the jumping spider eyes. I read it focusses by a movable retina. And they can also follow a prey by shifting the retina. So the spider can sit motionless and still follow the prey.

Aren't they amazing!

Wim

Beetleman · Post by **Beetleman** » Fri Jul 21, 2006 4:44 am

All I`m going to say is "WOW" to everything

rjlittlefield · Post by **rjlittlefield** » Fri Jul 21, 2006 7:58 am

Wim van Egmond wrote:About the jumping spider eyes. I read it focusses by a movable retina. And they can also follow a prey by shifting the retina. So the spider can sit motionless and still follow the prey.

Aren't they amazing!

They are indeed! Here is a snippet from the best reference I ever found.

http://www.tolweb.org/accessory/Jumping ... cc_id=1946. "<diagram> Note that the AME's [Anterior Median Eyes] are long and tubular, which helps their resolution (longer focal length, more magnification) but which means they have a narrow field of view. Since the AME's have a narrow field of view, the spider needs to point them in different directions to see different things. To some extent this is done by moving the carapace, but the eyes can move as well. This is not done by moving the whole 'eyeball', since the lenses of the eyes are actually built into the carapace. Instead the retina moves around, while the lens stays fixed. This retinal movement is accomplished by some small muscles: <diagram>"

For some more details and links, see the fourth post in this earlier topic.

--Rik