Any suggestions for improving ?

[All Ex]

I recently got this photo:



I use this set up:




And I shoot my stacks inside a black "dark box":




I covered every reflection surfase I see with flocking paper (the half of the "dark box") and as you can see in the second piicture I use a carton cilinder around my objetives.
My "dark box" has the option, with a small window, by placing colored cartons in an angle of 45 degrees, to acheve various backgrounds:



Given the above first photo and the all set up, I`m waitting for your suggestions in inproving the all thing.

[abpho]

Your light source looks very harsh. Do you understand lighting and light modifiers? Try and diffuse the light more. Make the surface area bigger. I used a Styrofoam cup as a diffuser, with the subject placed in the center. That way I got an even light all the way around my subject.

[zzffnn]

It looks like you had/have some diffusion there, but not enough for this subject. Its right side is a lot brighter than the left and some details were masked.

I prefer Scotch Matte finish tape (taped over clear plastics), over foam cups (which take away too much light).

[Pau]

Some observations and maybe easy to give advice:

- you get strong vignette. Please disclose what optics (lens and objective) and camera do you use.
It can be due to
+ the lens diaphragm too closed: try with it wide open in manual or AV mode
+ the objective coverage too small for the lens/sensor combo, for example with a 100mm lens the objective does not cover FF sensor except in few cases. Try with a 135 or better, a 200mm lens

- Too harsh light. You've put diffusers on the flash heads and I also can see a round reflector but it is not enough. Put a cylinder of white paper surrounding the subject, from the point of view of the fly it needs to see a full illuminated sky

- It also seems to be there some focus banding, try with much smaller steps

[All Ex]

abpho

I`ve used a sterofoam cap but some light rays from the wite surfase of it hitted my objective directlly causing bluerines.
These are peaces of styrofoam cups, from the outer side of them i`ve straighten the curvature of the cup to prevent direct hitting of light rays to the frond of my objective.
zzffnn

I`ll try your suggestion with Scotch Matte finish tape as well as to increase the deffuing surfase that abpho oposed. (In an other set up)
Pau

Sorry for the luck of neesesary informations.
I have a D800 for this photo I had the Tokina 100mm macro with the Nikon Plan 10X/0.25.
I always shoot wide open ( in this case f2.8 ) in manual mode.
The informations you give me on the combinations of my tube lenses are very helpful, I should use my 135mm tube. The stacks in this photo were 115 with a step of 0.021mm giving me a magnification of apr. 7.2X.
The combo you suggest (135 tube with the same objective) is giving magnification of apr. 6.5X (close one).
What step would you use in the case of the 135mm tube?

[Pau]

Not sure if with a 135mm you'll cover the full sensor, it also varies with the lens construction, if you already have it, try it, if not I would recommend a 200mm prime

About step size, you can try between 2 and 5 micron to find the most adequate for your needs/equipment.

For better info, search for Step size or DOF at the forum, there are many threads and links to formulas and spreadsheets

[All Ex]

I use the old MF Nikon lenses, I have the 135 mm Ais one
About step sizes things are quite fuzzy I thing, at least thay are not clear at all. I use the function: 2cn(m+1)/(m*m) were m:magnification n:f number,c: 0.029 mm (circle of confusion). But allways deciding the DOF, or the step if you prefer, is, in a rather significant degree, a matter of experimantation.
Anyway, thank you all for sharing your thoughts on my issue.