Focus stacking – lessons learnt

I think I am beginning to get the measure of the Nikon R1C1 speed-light commander kit/SB-R200 speed-lights, SB-R200 speed-lights, CombineZP and my home-built focus rail. The first lesson I learnt was that the R1C1 kit is fantastically capable. Set to manual and either using just the flashes or the flashes equipped with the extreme closeup position adaptors (effectively crude mirrors and diffusers that turn the flash beam to illuminate things within a few inches of the front of the lens) the lighting they produce with the 105mm macro and 50mm reversed standard lens I described in the last post, produce a really nice light that can be varied from warm to dramatic depending on the flash intensity, whether or not the adapters are fitted and the angle of illumination…

Warm (illumination from left and right, no adapters):

Modified by CombineZP

 

Dramatic (adapters fitted, one speed-light above the specimen, the other to the left):

Modified by CombineZP

Neither of the two images has been retouched. The am quite pleased with the lower one and will now take time to finesse it through CombineZP using all the available methods and the ‘thorough’ balance and align option. A bit of retouching and I might print it up!

The second lesson I learnt was that it is worth taking more images than you need to ensure that you have all the details you want available in the stack – it is very annoying to take 50 photos at 100um intervals only to discover you missed a vital bit of an antenna or some other detail. You can always abandon some frames….you can’t magic them up!

The third lesson was one of organisation. My pictures are acquired by ControlMyNikon 5.0. It is essential to take a few “sighter” frames so that you are sure the lighting is OK and you have the object centred in the frame etc. but then it is really important to either erase these frames or set up a new directory in which to acquire the final stack. I forgot and became quite confused about which pictures were part of the stack and which were not. ControlMyNikon has a great image browser and it is an almost hypnotic experience to watch the frames build within it.

The fourth lesson was the delay necessary between frames. The delay is necessary both for the vibrations associated with the movement of the camera to die down and for the flashes to recharge. As I learnt, if you decide to increase the flash intensity, the delay may need to be longer….really annoying to see the “ready” light stay green and the frames become underexposed!

The fifth lesson was that “mirror up” (MuP) doesn’t make much (any?) difference. I guess this is because the flash freezes any movement though I have read that with a good solid support it isn’t necessary. For me MuP is a problem because you need to activate the camera twice for each frame and my little microprocessor and the programme I wrote to drive it, didn’t allow for that (though it easily could). The first activation puts the mirror up and the second activates the shutter. Thus, if I use MuP every other frame is blank.

The difficulty with the R1C1 kit is that it is not possible to fix it to a reversed lens – I kludged up a clamp to hold it so that it fitted around, but did not touch the 50mm. I will need to make something more elegant for my future work. Finally, some kind of LED or other cold bright lighting is essential for setting up the pictures. I will get round to making something soon……

 

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About petermobbs

Inveterate meddler.
This entry was posted in Photography and electronics and tagged , , , , , , , , . Bookmark the permalink.

One Response to Focus stacking – lessons learnt

  1. Rompen says:

    Looking good! Great job with the slider 🙂

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