Black Spider

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hotrodder19
Posts: 62
Joined: Thu Sep 26, 2013 6:36 pm
Location: Perth, Western Australia

Black Spider

Post by hotrodder19 »

My first attempt at a black specimen, so questions to pose. Was a 5x attempt, flash 1/8 diffused, delay to shutter. Appears as though maybe too much exposure because of the shiny front on the spider. Are there specific parameters to use if photographing black subjects. Pic attached. Comments please.Image

Chris S.
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Post by Chris S. »

Hotrodder19,

This is not a bad first try. However, my bet is that your efforts will improve quickly.

To my eye, the immediate issue is that your flash's light is not spread out enough (aka, "not diffused enough.") From the viewpoint of your subject, the light should appear to come from all directions, or at least most directions. But here, your light seems to have been either a flash built into your camera--so popping up above the camera's center, or a flash mounted on the hot shoe, at about camera center. From the viewpoint of your subject, the light came from only one direction. (Or to put it more precisely, the light came from a very limited set of angles.)

There are quite a few resources that describe effective ways of diffusing a single flash. None of them come to my mind at present, so could someone more familiar with them kindly post a link?

Also, you could use two or more flashes, mount them on arms to spread them out, and--importantly--place diffusers between these flashes and your subject to spread out the light. Again, if someone post a link?

With a subject such as your shiny, black spider, it's a necessity to spread out the incoming light rays so that they hit the subject from widely varying directions.

--Chris S.

(fixed typo)
Last edited by Chris S. on Sun Sep 29, 2019 10:25 pm, edited 1 time in total.

hotrodder19
Posts: 62
Joined: Thu Sep 26, 2013 6:36 pm
Location: Perth, Western Australia

black spider

Post by hotrodder19 »

Thanks Chris for the comment. I did use a flash SB 700 on hot shoe and diffused. I can use two more flash units to see the difference. I imagine I will have to adjust their output somewhat if using 3 units ? The SB700 was on 1/8 power. I i use 3 units do I specifically need to drop the power of all 3 to get uniform lighting or would I keep all at 1/8 power ? Is this overall 3 unit system applicable to most specimen micro work or more specific to a subject that is dark in colour ? I look forward to further tuition.

Cheers hotrodder19

rjlittlefield
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Post by rjlittlefield »

hotrodder19, when I look at your image and your words I'm pretty sure that you have not really grasped what Chris S. is telling you about diffusion.

Here are a couple of illustrations that may help. (These are slides 39 & 40 of http://zerenesystems.com/presentations/ ... 280800.pdf , which is one of the "Other Slide Sets" listed on the Tutorials index page of the Zerene Stacker website.)

Image Image

I'm pretty sure that your lighting is like the one of the right, with a diffuser at or very near your light source.

Much better is to have it be like on the left, with the diffuser close to and wrapped around the subject, and far from the light source.

What you want is to have light hit the subject coming from a wide range of angles. This is completely different from the purpose of a typical on-flash diffuser, where the diffuser serves to make the light go to a wide range of angles.

--Rik

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