Penny macro contest - revisited


coker

Link Posted 01/03/2021 - 16:17
Can't remember the w/d on mine, Steve but for sure it was more than that!!!!!
How about a disc of (?) white paper. o/a diam. somewhere between that of the coin & that of the Q lens,,
with the most reflective (but non-glossy) surface towards the coin.
With an inner hole (just) big enough for the lens to "see" through.
Fixed (somehow) to the lens.
Thus making a sort of ring light, hoping for some of the light to spill "inwards" onto the coin face.
Position a flash in front, facing the camera.

If you see what I mean.......
Good Luck.

Roger.
The more I look, the more there is to see!
Last Edited by coker on 01/03/2021 - 16:23

Lubbyman

Link Posted 01/03/2021 - 16:45
coker wrote:
...Fixed (somehow) to the lens...

I do see what you mean. It's the "fixed somehow" that concerns me. The thought of mucking up a really nice little lens would give me sleepless nights...

I had tried making a 'Polo mint' diffusing ring from polystyrene packing to fit between penny and lens, the hole being the diameter of the front (rear?) element of the lens. The intention was to blast as much light into the outside edge and hope. Unfortunately, not enough light got into the edge to produce a decent level of illumination in the centre. Still, it was fun trying

Perhaps the next step is to build on your idea of a reflective ring between lens and coin by defacing the currency (shock, horror ). Drill some holes in the penny, shine light from back of penny through the holes, light reflects off white ring, illuminates letters on face of penny. Something for a rainy day...??

Steve

coker

Link Posted 01/03/2021 - 19:08
... said white paper disc could have 3 or 4 tabs, bent back over the body of the Q lens, then held in place with a rubber band.
"SHOULD" any light get though the gap' I think we should agree to the acceptance of any blown highlights!

Eh?


Roger.
The more I look, the more there is to see!

Lubbyman

Link Posted 05/03/2021 - 22:11
Sooo...

White paper disc designed, made and fitted to lens. Penny support system upgraded (i.e. no blutack now!) so lights on stalks can be properly angled. Paper and cooking foil snoot made for LED panel, to guide light into gap between penny and paper disc. Card protractor attached to DA300. K3 attached to DA300 attached to reversed Q01. Live view relayed (via HDMI output) to tablet as it's easier to check focus (for my eyes and varifocals, anyway). 29 very closely spaced shots taken (each one 1.3sec @ ISO800) and stacked. And the result is....




Not yet entirely satisfactory. Some tweaking of the penny support system is needed so lights can be better positioned to avoid the remaining blown highlights. But getting better .

Attaching the Q-S1 rather than K3 must wait for another evening!

Steve

coker

Link Posted 06/03/2021 - 08:21

Excellent!
You just can't stop now, Steve, can you.....??

APSC frame size is about 24mm long, I dread to think what the height of the penny letters is, say 0.5 mm.
Have you calculated the mag ratio onto the sensor?
Could it really be 40x odd?
What scale of difference would (sorry!) WILL the Q-S1 make?

Keep going,

Roger.

The more I look, the more there is to see!

Lubbyman

Link Posted 06/03/2021 - 11:46
coker wrote:
You just can't stop now, Steve, can you.....??

Not until the Q-S1 has been given a fair chance to show what it can do !! Might also try the original Q, which has an even smaller sensor.

The letters on the penny do seem to be 0.5mm (top to bottom). A quick on-screen measurement impies that the magnification ratio at the sensor is about 35:1. That won't, of course, change with the Q's as the lenses will be the same. But the crops due to the smaller sensors will give apparent increases in magnification by factors of 3.1 (Q-S1) and 3.8 (Q) relative to the K3. So apparent magnification (is that a real thing??) would (will??) be approx 108 (Q-S1) and 133 (Q).

The big surprise for me is how well the lenses are doing, particularly the tiny 01. Both lenses are being used in a way they were certainly not designed for, and it looks like a rather bizarre pairing, but they do seem to work well together. Whether they will hold their own or throw in the towel with the even more extreme challenge of the Q-S1 and Q remains to be seen.

Before getting the kit out again, though, there's the engineering challenges of modifying the penny support system and reducing the scope for tiny movements of camera and/or penny....

And then when it's all done, I'll get back to the original reason for getting the reversing, coupling. step up/down rings - bits of plants and flowers!

Steve
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