Yoshizen's Blog

Simple Arithmetic (2)

Was that the nature of Chinese electronics, I’m not sure, the LED ring light on a Z-light arm stop to work less than a month = switching control unit has brake down. Still, connecting the USB power direct, LED light itself can be light on. —– Then wait a moment. LED power is 5V, the Ring light was said to be 8W = its mean this lighting unit was designed somewhat for less than 2A (8W / 5V = 1.6A) (and anyway, the USB adaptor was 2A Max).

Connecting USB 5V direct to the LED light can be used though, it will be an over current to both LED and USB adaptor = soon they will be burnt out. To save the broken LED ring light, it is necessary to take a measure to limit the current = need to connect a resistor. To limit the current to 2A with 5V, we need a 2.5 Ohm resistor.

So, I connected 2.2 Ohm resistor (this type of resistor is getting harder to find though) (Why the wire of resistor was not cut short was, it get hot = need to disperce the heat) ( Note, for a sake of clarity, the photo was taken before applying insulation tape. )

With some improvisation, the LED light was rescued (though, without the brightness adjustment) —– I noticed that now, we can get the same LED light on Z-light arm for as cheap as £14 ! —– some of them may not break down. —– or am I expecting too much for £14 ? 😀


Rice Beetle

Rice Beetle(1)-A09A8055

This is the Rice Beetle I found in the Italian rice after more than 60 years lapse of time.  When I was a child, we were told to pick up and remove the rice beetle from the rice, before the mother cook it.  So, we spread the rice on a news paper and corm it to sort out the beetles.  It was the norm then that the rice was infested by the small beetles, elephant rice beetles.

I don’t remember exactly when its became we no longer needed to look for the insects. Anyhow, when the Co-op rice producer started to fumigate the rice with insecticide gas, the beetles were disappeared from the rice.

Rice Beetle(2)-000Many years ago, when I demonstrated the Japanese cooking to my friend’s family, while seeing me washing the rice, a daughter of the family shouted “Hey mum, he is washing the rice” —– it seemed, that the family has been eating the rice without washing.  Then the Mum started to preach me that the goodness of the rice is in its brown skin and the bran, therefore if we wash the rice, we will lose its remaining goodness etc.  So, I told them the story that there used be a lots of insects in a pack of rice and the reason why they disappeared was because the insecticide fumigation.  To wash off its remaining chemical is far more acute problem than a bit of nutrition. 

To take a photo of this tiny insect, I needed to use x5 magnification.  (Look at its magnified details, I noticed that this carcass got only two pair of legs = its mean the chest and the head was missing. )    Among my homemade macro lenses,  I chose to use the Instamatic Macro and the LED illumination.   Still, it was always the case, improvised Hi-magnification macro is very awkward ( = x5 magnification means the image is 1/25 dark, needs minute minute focus, sensitive to the shake 5 times more etc) — nevertheless it was a fun, especially, this was the record of the very rare encounter = I met this old friend again after 60 years absence.  I was really grad to see that they ARE also surviving somewhere on the earth.  



Make LED Ring Light

While hiding in my cave (:-D ) I found the time to do building work (Since, as

I don’t have a habit to watch TV (I don’t have a TV 

nor able for streaming video signal on USB dongle 

connection) or DVD,I have to DO something 😀 ).

From other project where I changed White LED to 

Color LED I got mountain of White LED, I decided

to make LED Ring Light which can utilize

those LEDs in number.

Ring Light can create (almost) shadowless  

image, or having faint shadow surrounding the  

subjects, some says, it is the Holy Grail in the Lighting effect. 🙂


Funny situation these days is, we can get the LEDs from the products,  

such as an LED Work Light from Lidl which is using 40, 60 LEDs inside,

as cheap as £15 = much much cheaper than to buy LED itself from an

electronic supplier = hence disassemble and use them to make such as

a Ring Light can save a cost a lot. (advantage is, that the LEDs has been

selected and tested already by the maker and the Lidl, hence there is little

chance to get old type dead-stock from unknown supplier in the Net  🙂 )


Basically, all about LED Ring Light is “How to mount a ring around the

lens front” — other than this, everything else are straight forward =

just put a lots of LEDs and connect it to the battery.

—– Sound easy though, the trouble is, not like in a good old days when

most of the lenses from one camera maker has only one or few filter sizes

(such as for Pentax = 49mm, Nikon = 52mm, Canon = 58mm etc), but

now as the role of filter is diminishing (now most of the visual effects were

created by Photoshop), lens doesn’t need to have the same filter size =

in the other words, to make a ring light capable to be used on many lenses

is nothing but a headache. 🙂

To make the situation even worse is, the use of Zoom lens is the norm now

and as the lens starts from wide-angle, it is necessary to make ring light NOT

vignettes (not cut off the corner of the image by the additional protruded edge)

= it got to be much larger than a front element of the lens.

On the other hand, some lenses especially on the smaller camera is getting

even smaller and many of them has even no filter thread on the front at all.

= it mean, the ring light got to be designed and made for the individual purpose

and the choice of lens. —– (hence, better to do DIY 🙂 )


I decided to make one for my 100mm macro and other for 24mm~70mm Zoom.

So that the first sample here is to make it for my Canon 100mm F2.8 Macro (not 

the latest L type — it came to the market only two months later, but this one is

pretty sharp as well, and I like its smaller front lens which would cast less shadow

when we close to the subject and easier to give a lighting.

(in extreme close-up, large front lens allows only side-lighting. 

And I don’t see much of help from the so-called Image-stabilizer = if it helps two

or three stops, why not just set higher ISO speed.  And having very delicate lens

shifting mechanism which is suspending the lens element in the air by the

magnetic coils or ceramic motors, it would make the lens even more sensitive to

the shock.  🙂 )

[A ring to mount the LEDs can be made from a Phenol plastic board with copper

track for electronic circuit, to even just a card-board paper (if it is just for an

experiments, 1 mm thick card-board paper would be good enough) or to mount

the LED from the the back (through a hole) = Art-mounting-board is a good choice.

(Still, precisely drilling 30, 40 holes, this work needs to have a good Zen mind.)  😀

Which ever the material, you need to find the diameter of the ring and cut the

material.  ( I think the photos here are self-explanatory. )

Use caliper to find the diameter under the bayonet to mount lens hood. 

If no caliper in hand, use right-angled paper.

Then draw the circles of its mounting diameter.  I’m using a sharpened needle

mounted on the compass to cut the paper as well.  And cut the Phenol plastic

board, I’ve clumped a cutting blade on the compass.

A paper ring cutted with diameter of the lens  and outer diameter was placed

under the bayonet and the shape of it was taken.   (To place this paper ring /

template, under the lens bayonet, the ring needs to cut on one place to open)

Then the shape of the ring and the bayonet craw was copied on the card-board paper. 

( On the card board paper, two additional circles has to be drawn, + 6 mm larger

than inside diameter and  + 8.5 mm ) — To plot the position to put LED, divide 

+ 8.5 mm circle to 8.  Then, within a semi-circle of 1/8, find equidistant point to

put LEDs — In my case every 11 mm and the holes to insert LEDs are pierced

(Photo above middle)  If you put too few LED you will have ugly multiple shadow,

or if you put too many, the battery will run-out rather soon.  It is a compromise.

(sort of the standard is, put the LED at every 8~12 mm distance )

In this design, I’m connecting all the

LEDs in parallel, and you can see

the different way to connecting them.

Left Top = if the LED came from

another device and having already

trimmed leg, you have to make sure

to insert all of them keeping the same 

direction (inside of LED you will see

narrower pin (+) and the broader pin (-),

you have to insert LED all in the same orientation, say (+) = outside of the ring.

And connect them using a wire such as from telephone cable (better polish it 

before soldering) by running it inside and outside of the LED leg alternative way.

Then you will have two wire ring on the board.

Photo Middle = If you got newly bought LEDs (assuming all of them are having 

the same color and the brightness — some are more blueish 🙂 = the cheaper you

pay, you will have headache — To insert LED’s to the board keep longer leg (+)

outside, then you just bend each leg to touch next LED and cut excess, then

solder each leg next by next = you will get two wire ring on the board.

Photo bottom = If you don’t have soldering facility yourself, and no one to ask, 

don’t worry still you can do !  = Insert all the LED to the board (such as photo

above) always keeping longer leg outside, then bend the leg towards the next

LED and twist the leg wire to next one. Then bend next one’s leg to third LED’s

leg and so on (connect last one’s leg to the first one, need to insert the leg-wire

to the gap between the board. = you needs to have a bit of work.

Use a narrow-headed pliers or tweezers would be a good help.

When you got the board, with all the LEDs were connected together, then

connect the power wire to each wire ring —> and connect to the 4xAA battery

through 2.2~10 ohm 1W register. (this is the MUST ) = If LEDs weren’t light up,

connect the battery other way round. (Change polarity )   2.2 ohm register will

give you brighter light but shorten the battery life = 20~30 LEDs will drain the

power nearly 1 A from 4xAA battery it would last less than 1 hour, but with

10 ohm, it would not be as bright though, in an intermittent use, your battery will

last much longer = it’s depend on how you are going to use it. (Put a switch to

select High and Low would be an good idea).

( The register may get hot though it is normal = pay attention to the layout and

the design for this heat problem.)

(For serious video shooting, use 2.2 ohm and 4xD battery, and make others envy.)

If only a part of the ring was lighten up, it is the point where your connection was

loose = check the connection and tighten it up. If one or two LEDs were not

lighten up, it’s mean that LED was dead and needs to replace (it’s an awkward job

= it’s better to check all the LED before hand ).

Then, fix the power cable to the ring, tie it with strong thread like the photo above

right, or use heat-gun glue.  (I’ve covered the end of the cable with heat-shrink

tube for better protection)

When everything went well, end result should looks like this.

= Voila, LED Ring Light !

(In fact, I’ve used paper one for a template to make it on a Phenol plastic

circuit board.) —– Further to this, such as where to keep or mount a

battery case is largely depend on you.

And I’ll show you my final product in the coming post.



A while ago I was introduced to a guy who needs to have some helps for his electronic project.

This guy Richard has been running his shop-sign design business near the work shop of the

Open Wifi Networking people / OWN, and he was introduced me through this group.

As he wanted to expand his design to LED light sign-board, but without having enough knowledges of

electronics. ( —– good boy. I like this kind of people. Keen to study and challenge new field.)

(Any how, I myself started a hobby of electronics from scratch

without having any formal education or training)

He had started to make sign-board using a kit bought from China —– and having mountain of

problems, the power supply, heat-up, etc etc. (May be it worked in China though, this country got

much more strict Safety regulation and the customers are more fussy, and so on)

Basically, the Chinese design was rather cleverly simplified, using less components —– would work

just within the limit and under an ideal condition.

Though, the trouble of bespoke designs are, they are not always the same design, and the number

of LEDs on the board are not necessary the same number.

So, I suggested the modification and the change of the components, power supply etc etc,  in fact

quite a lots of works needed to make them perfect    🙂


On the beginning, he tried to pay for my help. I told him “My help is free. And even if he want to pay,

he can’t afford my formal charge”   “One day, if I need, I may need to ask your help”

“So, just glad to receive a help from others, and give a help when he saw if others needed”


——- Then, he found the Chinese toys using LEDs and showed me if they can be used to control the

electronic signal in the sign-board.

Modification or adaptation of electronic circuit is much easier than to make a tandem bicycle out of

two broken bicycles (which needs to have a lots of cutting and welding —– a messy business)

As a matter of fact, I’ve been doing many of those kind of adaptation.

A video clip of my rotating  LED disco costume in Youtube was made out of a Chinese toy too.

When I saw the complicated lighting pattern of 5 LEDs in the small toy, I’ve got the idea to utilize it

(then, I made more than 10 design and the prototypes —– and one end-up as a fancy disco gadget 😀 )

If I design and make the same from scratch, by using gate ICs or a micro-controller IC, it would become

quite a size and impossible to rotates, let alone to mount it on a disco costume.

Since Chinese manufacturer designed and made it as a cheap toy, expecting to sell millions, they made

all the controlling circuit and the memory in one custom IC, everything is in a thumb nail sized board

—– so that, I’ve bought 20 of them 50 pence each 🙂 —– what a bargain 😀

Most of those ICs in the toys which execute a pre-programmed

routine is having a digital memory and its execution speed is

clocked by an internal RC clock, and its frequency is

supply voltage dependent, its mean if we change it, it could

slow down the speed.

The toys, Richard found was rapidly flashing RGB LEDs disco

pendant kind.   Those electronic circuit can be modified to flash

the letters on a sign-board by adding higher current transistor,

and can have more effective speed or giving more interesting

random movement as well.

And by using much higher supply voltage, it can light up lot more number of LEDs —– the variations are

endless —– after all, they are so cheap,  try this and that —– any faliuer wouldn’t cost you much.

Try to analyse and modify the circuit is a kind of game and a fun. —– and I made user friendly, ready to

use small board for him (and his assistants) to make sign-board.

—– rest of work is for him / he is the designer.    I was just an adviser.

It was an interesting occasion to see a person rapidly learning and succeeding.

This is the Zen at work. (for me and for him)

Let the things to come and happen.—– In Buddhist’s view, it is not an accident. 

It’s happened as it should be.

Be flexible in the brain / in the way of thinking, and to the occurence in the life,

and above all,  just do what required there in its best.

Hence, I was happy and he was happy too.

The day and the life in total would be quite fruits-full. ( with a lots of fun as well 🙂 )


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