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Thread: Macro Ring Light

  1. #1

    Default Macro Ring Light

    Here is my take on a macro ring light. The concept is not new but for me need and availability have handily come together. I just bought an Olympus TG5 and housing; two of its features are super close macro and a fast frame rate, up to 20 fps. I do not have strobes but it is evident that no flash will recycle that fast.
    Recently a number of ring COB LEDs have been available, popularly used on car headlights and often termed ‘Angel Eyes’ from a well known online market place.
    I have not found a spec sheet and the ones I purchased came with a buck driver giving 350mA at ~9V from a 12V supply for all sizes from 60 to 120mm. This can easily be replaced with a XL6003 based boost driver (available from the same place) giving 650mA. I have coupled these with 80mm and 90mm ring with 21 and 22 LEDs (sets of 3 in series) which drive each LED at 30mA. Power comes from two 18650 to give 7.4 V controlled by a clickey switch and logic level MOSFET.
    Drawing about 12W I recon the setup is good for 1000 lumen.
    Photo show the set up, it is a bit crude, but has done a good job as a ‘proof of concept’ Mk 1.
    Other photos show it in action and what I think may be the photo I was taking at the time. It takes more than a nice camera and a bright light to get the perfect photo but I think it shows its capabilities. This little shrimp was on a Feather Star and demonstrates the even lighting while the Cuttlefish was from a series of shots of it while constantly moved and changed colours and shows the benefit of being able to pick the perfect (well best) frame of a swimming subject from a series of shots when neither the subject or photographer are perfectly still. (Beware of shooting at 20fps, you are left with an awful lot of deleting to do).
    I now fancy that the LEDs can be driven closer to 60mA, and have tested a ring for a couple of hours at 45 mA, which should give a 50% boost in output.
    I would be glad to hear from anyone who knows the true max current of these COB lights.
    Construction is pretty obvious with bonded Acrylic, bolts and O ring.
    Mk2 is already under construction with a more ‘compact and finished’ look and hopefully brighter 45mA LEDs.
    Mk3 might go for the ‘full’ 60mA and a third ring which should push it up to nearer 3000 lumen.


    OK I will post photos when someone tells me how to post from Google Photos.

    Rod


  2. #2
    Flashaholic* DIWdiver's Avatar
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    Default Re: Macro Ring Light

    Sounds like a nice project. I'm anxious to see pictures.

    First you need to have pictures somewhere you can link to them. The click the 'insert image' button and paste the link in the window that comes up.

    Remember, forum policy is that pictures posted this way must be a maximum of 800 x 800 pixels. You might need to use an editor to crop or reduce resolution before posting.

    If you want people to be able to see the optimum picture resolution, you can paste a link to the full size picture directly in your post.

  3. #3

    Default Re: Macro Ring Light

    Thanks DIW, Sorry about the ineptitude.
    I hope this linkg will take you to the photos.
    https://photos.google.com/album/AF1Q...UjP6hyFMo4EkD8

  4. #4
    Flashaholic* DIWdiver's Avatar
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    Default Re: Macro Ring Light

    Nope, link doesn't work.

  5. #5

    Default Re: Macro Ring Light


  6. #6

    Default Re: Macro Ring Light


  7. #7
    Flashaholic* DIWdiver's Avatar
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    Default Re: Macro Ring Light

    Nice job!

    How big is that cuttlefish? It looks smaller than I thought they usually are (maybe juvenile?).

    Did you etch or mill that circuit board yourself? I haven't seen one of those in a while.

    In most circumstances, the LED current is limited by die temperature. As long as you can keep the dies cool, you can keep cranking. To that end, mounting on copper or aluminum with good thermal path to the water would allow for much higher currents.

    Basically, the higher the die temperature, the faster the LEDs will degrade. Cheap ones will degrade faster than ones from quality manufacturers. Given that the life expectancy of your ring light is probably tens or hundreds of hours, you can tolerate substantial degradation of the 10,000+ hour 'standard' life expectancy.

    Unfortunately, without good data from the manufacturer or experience with those particular emitters, it can be difficult or impossible to put numbers to these ideas.

  8. #8

    Default Re: Macro Ring Light

    Thanks.
    The Flamboyant Cuttlefish was 2 or max 3 inches overall which seems to be standard for that species. Cuttlefish are a novelty to me and most we saw on this trip (to Lembeh) were much smaller, just a half or one inch.
    The circuit board was engraved using my minimill which I have recently converted to CNC.

    I take you point on the LED cooling, it occurs to me that as you up the current the efficiency drops off and you get more heat and less light per mA so I guess I will stick at 45mA.

    Rod

  9. #9
    datiLED's Avatar
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    Default Re: Macro Ring Light

    Cool light project, and awesome photography! I'd love to see some more pictures of the light and underwater discoveries.
    I am currently accepting limited mod requests. Please send me a PM!

  10. #10

    Default Re: Macro Ring Light

    Quote Originally Posted by rodex99 View Post
    These look amazing! Do you have any more info on your setup?

  11. #11

    Default Re: Macro Ring Light

    Hi Guys, tanks for your interest and sorry to be so slow to reply. Unfortunately I am more of a snapper than photographer, I do not have any social media feeds and whist I have dozens of photos I would gleefully share I think the moderators might object if I used this forum to show off my photos. I am more than happy to answer specific questions about my set up, and if you are interested in Lembeh I can recommend two aussies I met there, Steve Winkworth on Youtube and Neil Vincent on Instagram. I am sure there are many others you could Google.
    Rod

  12. #12

    Default Re: Macro Ring Light

    I can't believe I stumbled onto this today. Just got back from 2 weeks in Cozumel... My wife had a Canon S100 in a housing that worked great in shallow waters but wanted something better. When the S100 got knocked onto the floor and jammed the lens, I went looking. Now we have a new-to-us Canon G15 for which I got her a Knog LED light. Good but not what we need. I use a GoPro with a Switchblade filter/macro lens and a cheapo LED light but that's not so good either... Time to upgrade too.

    Upon return home, she tasked me with building a ring light. Finding this thread was heaven sent. The Angel Eyes idea looks like the best way to go (for the cash), the only part that remains is a watertight housing for them and for the electronics.

    To that end, can you (@rodex99) please post some more pictures of the setup you built?

    The good news is that I have access to a pressure pot for testing -- it's how I verified that the eBay-sourced G15 housing was watertight to 130'.

  13. #13

    Default Re: Macro Ring Light

    Hi Claude,
    I will reply soon but have been tied up and am totally frustrated in every attempt to post a photo on the forum.....I have done it before but cannot do it again!!!!!!!
    Rod

  14. #14

    Default Re: Macro Ring Light

    Here are some links to photos of my Mk 2. I have reduced the bolts to 4 and used embedded helicoils instead of through bolts.
    https://photos.app.goo.gl/p7CjcPedTysydWBs8
    https://photos.app.goo.gl/DaGFQ3Jh2ut2ar7Q7
    https://photos.app.goo.gl/vAHM5r22K15SL48s6
    https://photos.app.goo.gl/wpHX1HNDqPmwkKZi9
    https://photos.app.goo.gl/XYUdfXY7gsQPjv8J8
    Along the way I have learnt.

    1. Acrylic can be readily bonded with solvent cement to produce an almost invisible joint, waterproof and as strong as the base material. I ignored recommendations for two part or other special ‘waterproof’ glues, the one I use is called ACRYweld. Degrease the surfaces, hold them apart with pins or fine wire and use a hypodermic syringe, as fine as you can get to apply the solvent. Best if the lower layer is a few mm larger. The solvent will then flow by capillary action to fill the gap. Remove the pins pdq and leave to set. If need be I have drilled a small hole in the top piece, and dripped in the solvent in, which again spreads to fill the gap and seals the hole.
    2. It was not a problem when the solvent flowed over the LEDs
    3. To seal the battery compartment I use 4mm O rings which are obtainable (in UK) in just about any size you need, unfortunately it is difficult to obtain them in anything other than 70 Shore which is a bit hard for this application but works OK. I try to compress the O ring by 20-25% and found I could do this with bolts 80mm apart and 10mm acrylic. Greater spacing or thinner sheet will result in uneven compression. You want to completely close the gap or else the water pressure will close it for you and leave loose bolts.
    4. Battery cover bolts engage with Helicoil inserts.
    5. I originally used plastic battery holders but found these could not be relied upon to always give good contact. I have now made a 2 x 18650 battery pack with protection circuit.
    6. I use a toggle switch but could not find one rated for the current so the switch controls the gate of a low resistance logic level mosfet. The ones I have used are IRLB3034.
    7. Photo shows a complete circuit board with the XL6003 boards, 47uF capacitors on input and output, mosfet and drawdown resistor. The battery pack is complete with mounting board for the toggle switch, barrel connector for charging and screw terminal block for connecting to the drivers.
    8. I have added a finger grip to the front and thumb grip on the back together with a rounded surface to make for more comfortable handling.

    Good luck and I hope this helps.
    Rod

  15. #15
    Flashaholic* lucca brassi's Avatar
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    Default Re: Macro Ring Light

    all kind of those rings you have for microscopy https://www.ebay.co.uk/sch/i.html?_f...+ring&_sacat=0 with drivers

    a good idea it is to run light by segments to get some side illuminated object an than photo like

    https://www.ebay.co.uk/itm/AmScope-L....c100005.m1851
    Last edited by lucca brassi; 08-28-2019 at 03:46 AM.

  16. #16

    Default Re: Macro Ring Light

    Gentlemen I thank you for getting back on this. The ideas about material and bonding (and helicoils) are all valuable. As for manipulating 10mm acrylic, I was discussing this with a friend of mine with a full-blown shop and he told me to draft it up and he's CNC anything I wanted (I've done some free consulting for him...).
    A couple of things:
    1) My thought is to use ring LEDs such as are used around car headlamps, often called Angel Eyes, and I'm guessing that's what you are using, like these on EBay. There are lots of different ones.
    2) Instead of a toggle switch, a magnetic switch, no seal required.
    3) The camera is a Canon G15 with a Canon housing (super cheap on EBay and passed my 130ft pressure test) and it has a big nose. The whole design will depend on finding LEDs to fit around it and allowing the camera to be close to the ground.
    4) I am good with electronics (engineer) so I think that is the least of my worries.
    5) Lucca's comment about lighting the ring in segments is a good one (I had the same discussion with a couple of others) and would be possible but require me to make my own ring from discrete 5050 SMD LEDs. I see that as Version 2. Remember, the perfect is the enemy of the good.

    On the other hand, if you are careful, steady, have extra light and a closeup lens, you can get some good shots with a GoPro.

    Looks like I figured out how to post a picture. Not only that, it's from an Instagram post!
    Last edited by CaptClaude; 08-28-2019 at 11:49 PM.

  17. #17

    Default Re: Macro Ring Light

    Here is a 'handy' accessory I just made that allows me to 'digitally' reduce the output from one sector.................I know it is bad but just could not resist.

    ...and it does work.


    .

    More seriously, just stick some black tape on, if you do not like it, peel it off half way through the dive.
    "Remember, the perfect is the enemy of the good"

    Rod

    PS your angel eyes look just like mine, and if they are different...there is a 50% chance they are better

  18. #18

    Default Re: Macro Ring Light

    OK, that's good. And believe it or not, has given me an idea for a mechanical shutter...
    I'm still a little fuzzy on the subject of o-rings, but I assume that some self-study will fix that. If you have any resources, shoot them my way.
    Below is a product of the Canon G15 my wife currently uses. I found it on EBay and have a search running for another. We were corresponding with our favorite critter-book photographer and he told me that most of the pictures in his book were taken with a G15...

  19. #19
    Flashaholic* lucca brassi's Avatar
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    Default Re: Macro Ring Light

    Here is a 'handy' accessory I just made that allows me to 'digitally' reduce the output from one sector.........
    ........I know it is bad but just could not resist.

    ...and it does work.
    KISS

  20. #20
    Flashaholic* DIWdiver's Avatar
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    Default Re: Macro Ring Light

    Quote Originally Posted by CaptClaude View Post
    I'm still a little fuzzy on the subject of o-rings, but I assume that some self-study will fix that. If you have any resources, shoot them my way.
    Apple Rubber's Seal Design Guide will show you just about everything you want to know and then some. I have a hard copy from last millenium, and I love it.

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