Death Ray Ultimate Macro V2.05

Started Jan 26, 2015 | Discussions thread
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MightyMike Forum Pro • Posts: 38,917
Death Ray Ultimate Macro V2.05
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Some of you will remember my first ultimate macro device from 4.5 years ago, design for up to 2:1 macro and constant light with fast shutter speeds seen here...

http://www.dpreview.com/forums/post/34413472

Back then i had envisioned this new idea soon after i built the original, however certain items weren't available in small batches and the project was shelved.

Fast forward 4.5 years as i study the idea of tilted optics for macros and you get this...

You can't see it but there is a K20D and a rather large battery pack behind the apparatus, details to follow

Now I already know i want as much light as possible and to some this may seem extreme however the other part to this whole device is the lens, and more specifically tilting. Things i learned and have to overcome.

- you can't just tilt any lens, even lenses with larger image circles might not be good off access

- The effect of the tilt is related to the focal length and magnification, The longer the focal length the weaker the effect, the higher the magnification the weaker the effect. a very hard balance to achieve in macro

- typical tilting macro lenses only tilt to 8-8.5 degrees which is so little it has very little effect in macro, my device using several stepping rings, a metal hood and a rubber hood and some spacers provides me with approx. 25 degrees tilt and 2:1 magnification with a Rodenstock Rodagon-WA 40mm F4.0 lens

- When tilting a lens on a K-3 you start to lose the top 1/3rd of the frame in the OVF and this tilting leads to major metering flaws, approx. 1 stop at 8 degrees in early tests and as much as 5 stops at 25 degrees in the current rendition. the metering and visual appearance is fine in LV

Unfortunately the device needs some more fine tuning, the lens though darn good forces me to use a working distance of just shy of 6cm which is really just too close, the problem with increasing that distance is you either have to decrease the magnification or increase the focal length and since i don't want to decrease the magnification i'm stuck with getting less affect from tilting with a longer focal length lens.

Now to the Death Ray... each light is designed to be run at 29.3V and take about 500mA and produce 1720 Lumens with a 120 degree FOV without a reflector. However I've designed this to run at 30V and approx. 600mA to produce approx. 2100 Lumens each... however with the reflector concentrating the light to a 24 degree spread the brightness is magnified by 25 times allowing for 52500 lumens to be projected from each light or 420,000 lumens out of the system. So after doing some fancy math i think i figured out that i was projecting over 100 time brighter than sunlight at a distance of 15cm from the lights (now my math may be off a bit and up for some interpretation but heck its one crazy bright light)

Not showing full brightness as the power supply module though within spec is unable to supply the lights enough Amps at 30V to get the affect i want.

This leads me to the next part, the project isn't quite complete in that i need to get a power supply DC-DC boost converter that can handle 144W at 30V, I've already got one on order!

In early tests the lights mounted on small 4cm x 4cm heat sinks with airflow constrained by a non running fan the heat sink will heat up to over 30 degrees above ambient in just a couple minutes of operation, however with the fans on heat is a non issue... Except... one light running at full power can raise the temperature of the subject at 15cm by 5-6 degrees within a minute, imagine what 8 light might do.

As this is effectively the first variant to be tested certain adjustments will be made like the power supply but also i will make the lights attach to a lager ring expanding the array by nearly an inch.

What the heck powers this unit that is still portable?

What you see here is 4 6V 7.5Ah batteries hooked together to give 24V 7.5Ah, this gets converted to 30V 4.8A through the power supply seen in the next photo (however as stated above the power supply isn't capable of giving me 4.8A at 30V, all it give me is 3A at 30V) There is also a smaller 12V battery for the fans you'll see in some of the photos.

The original power supply converter...

The new one may not need fans and this one only needs fans if run at a higher watt level which is not available at 30V

From the power supply we go to the control box mounted on the hotshoe

The control box has 10 switches, 8 for the individual lights, 1 master for all lights and 1 master for all fans. the system is designed to be modular so that you can turn off and remove lights you may not care to use, not to mention the modularity of having all the units disconnect from each other for other applications. You can likely make out the tilted lens apparatus in this photo too and again i stress the camera its mounted on in this case is a K20D, each fan and light combination has 4 wires going to it so it does get a little tangled but once setup its not that bad. The original control box was mounted closer to the camera but the wires put too much stress on it that the hotshoe broke off the control box and i has to quickly improvise a new solution.

The fans...

The fans light up with a blue LED when on of course, they are mounted on mini ball heads, my friend helped me cut 1/4"-20 threads through 4 of the fins in the heat sinks. This allows the to me maneuvered and the mini ball heads can each individually be removed from the ring they're on (a 77mm metal lens hood) they too are attached with a 1/4"-20 tripod screw with d-ring. We also didn't just drill 1/4"-20 holes in the metal hood but shafts going back towards the camera do the light unit just needs to be loosened and slid back to be removed. The reflector is designed for the LEDs but they're designed to be used in a static environment so the reflector is only held on by a tiny bit of sticky pad, shout it be bumped the reflectors would fall off so i built a sturdy cage around the reflector to hold it in place.

I may be forgetting details about the project but they might come out in follow up questions in this thread so until then here are a couple more photos of the device.

The black things in the corner are quickly made covers for the lights as the yellow "bulb" is a soft sticky resin that you don't want damaged or dirty, they're held on to the cage by neodymium magnets

Now though i have tested it on live subjects i didn't do so well, the poor butterflies got very uncomfortable under the lights and i was only using 5 of them at first, then 3 then 1. now don't get me wrong they liked the warmth initially but prolonged exposure of more than a few seconds started making them uncomfortable. The photos that i post today are nothing special, i haven't done any focus stacking yet and they are just what they are, more and hopefully more refined photos will come in the next few weeks.

Clearly static subjects were easier to work with

Special Thanks to Ian for helping me build the device, to Brian for helping me wire the device and find a power supply for it, to Jeff for advising me on some topics and supplying the batteries at a good price.

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Mike from Canada
"I am not a great photographer! God is a great creator! All I do is capture His creation with the tools He has provided me."
'I like to think so far outside the box that it would require a telephoto lens just to see the box!' ~ 'My Quote :)'
http://www.michaelfastphotography.com/galleries/VP-BDI_3a.jpg
http://www.airliners.net/search/photo.search?sort_order=views%20DESC&first_this_page=0&page_limit=180&&emailsearch=mighty_mike88%40hotmail.com&thumbnails=

Nikon 1 V2 Pentax K20D Pentax K-3
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