Big beetle, small beetle...

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rjlittlefield
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Big beetle, small beetle...

Post by rjlittlefield »

I posted out this shot last night as part of a technical discussion.

But maybe you'll find it interesting as a picture, too.

Image

The larger beetle is a Long Horned Wood Borer (Coleoptera:Cerambycidae), total body length 75 mm from posterior to mandibles. It's from Scottsdale, Arizona -- I found it lying belly up on a sidewalk outside a hotel room years ago. The smaller one is a Carpet Beetle (Coleoptera:Dermestidae), total body length 2.5 mm. It turned up in one of my windowsills at Richland, Washington.

The subjects are posed, of course.

--Rik

Canon 300D, Sigma 105mm at f/8. Shot at 1:1.5, cropped for presentation. Reproduced here at about 16X life size.

beetleman
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Post by beetleman »

very good photo Rik, I like it alot :lol: I love the wrap-around eyes on these large longhorn beetles and you are right, I never find carpet beetles in the carpet, always on the window :wink:

EDIT: A question on your technical discussion. How do you come up with the length of your scale bar. Do you measure something on your specimen...easy in this case, and draw it in during processing? I know it is different for Micro.
Take Nothing but Pictures--Leave Nothing but Footprints.
Doug Breda

rjlittlefield
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Post by rjlittlefield »

beetleman wrote:How do you come up with the length of your scale bar. Do you measure something on your specimen...easy in this case, and draw it in during processing? I know it is different for Micro.
Nope, no different at all -- you just get to use a bigger measuring stick for Macro. :wink:

The key trick is to shoot a picture of a physical ruler using the same lens settings -- including focus -- as you used with the subject. Then just use your favorite photo editing tool to transfer a measurement from the ruler image to the subject image.

The picture below illustrates one approach.

Using Photoshop, I added the image of the scale over the image of the beetle. I set the image of the scale to 25% opacity so I could see the beetle through it. Looking at the beetle and ruler together, I decided that a 5 mm bar would work well. Using the marquee tool, I selected a region a couple of pixels high and however wide it needed to be, to line up with 5 mm on the ruler. Then I filled with black in another layer, to draw the scale bar. The job was completed by removing the layer containing the image of the scale, and adding "5 mm" as a text layer.

Image

I always do these things as layers so I can freely move them wherever they need to go to fit with the picture.

My smaller subjects sometimes need a scale bar less than a millimeter long. In those cases, I've traditionally used a slightly different approach involving some number-crunching to figure out how many pixels wide the scale bar needs to be. It's described here.

--Rik

beetleman
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Post by beetleman »

Thanks Rik, I do have a small metal ruler with the smallest marks of .5mm. Like Wim says...I will have to remember to take the picture of the ruler :wink: Thanks again for the info.
Take Nothing but Pictures--Leave Nothing but Footprints.
Doug Breda

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Post by Cyclops »

That was so cool,at first I thought, aye up wheres the second pic! Then I had another look and saw the tiny one on the big ones face!
Neat trick with the ruler BTW.
Canon 30D | Canon IXUS 265HS | Cosina 100mm f3.5 macro | EF 75-300 f4.5-5.6 USM III | EF 50 f1.8 II | Slik 88 tripod | Apex Practicioner monocular microscope

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