Measuring digital microscope

There are a lot of cases, when You will need a microscope. For solderind I use a 10x/20x stereo microscope, a normal optical one. At 59 years you can no more see small things..

But to make a measuring, or to take macro photos, there is much better a digital one. I searched a LOT OF TIME to find a real good and cheap one. Unfortunatelly all cheap ones promise You fullHD resolution – but only the signal is fullHD – the sensor is a poor quality 0.3 MP (480×640 ) sensor.

And then I have found this one. Is real 2MP chip, and … does not work with the software which is adviced to be used. Hrrrrr.
After some search I have found a software from the same chinese manufacturer, also freeware, which fits perfect. You can make the calibration of the choosen magnificaton with the attached etalon, and measure linear or angular dimensions.

Normally I never make advertisment for Aliexpress, but this time here is the link (I have the USB version):

UPDATE

Don’t buy from here.

For a project I needed 2 more pieces. I ordered them. Other chip inside …. 640×480, with extrapolated picture to 1920×1080. Shit.

Now I have to fight to get money back.

https://www.aliexpress.com/item/1005005511840611.html
(1000X Digital Microscope Camera 2in1 USB+WIFI Portable Electronic Microscope 8 LED Magnifier For Skin Testing Cell Phone Repair)

And this is the hiView application – for measuring:

https://apps.microsoft.com/detail/9p146nvzjd0j?hl=en-us&gl=HU

Canon 6d2 – error 20

Mirror box replacement? …. Not in each case!

I have got a 6d2 on my desk. Camera in very good conditions – but with err20, shooting not possible. Verdikt of the official Canon service: mirror box replacement (ca. 350 EUR).

In the camera were less than 5000 exposures, but over the warranty period….

I was on the limit to disassemble it, to fing out, what is wrong in the mirror/shhutter actuator, but I rather started to read others blogs about this faults. I have foung one, with a mention, that in 10% of the cases the problem is caused by a contact problem on a flex.

I have got in the meantime a donor part – has been replaced by the official workshop for the same reason. I studied it – so this photos have been made about the donor part, NOT the repaired 6d2.

After opening the latch, pulling out, cleaning the contacts, rubbing in place, closing the latch THE CAMERA WORKS!!!

What is the best of this repair: from my side, less work, of course (and the customer will pay not for the 5 minutes of cleaning a flex, of course – but for sure less, than a mirror box replacement.

From the customer’s side: the camera remains in it’s ex works state, no readjusted sensor etc etc.

Better for everyone.

Never give up searching a contact problem.

Canon 24-70 F2.8 USM – the unidentified FOCUS HUNTING

I repaired LOTS OF lenses with focus hunting, most of them 17-85, causes by excessive grease in the barrels, creeping on the incremental sensors plastic elements, causing instability in determining th executed focusing movement.

After the routine disassembly this time I was not able to find any grease or other contamination. I had fortunatelly an another 24-70 on the desk (with aperture problem).

I interchanged the mainboard – the same symthom, so the mainboard was working.

Ok, must be the USM. But for this old model there is no (new) sparepart available, or I couldnt find it. And anyway, I dont have 3-4 weelks to wait for it.

But… I have some other USM s in the scrapheap. Absolutelly other form outside – but the active part seems to be similar.

To be sure, I compared them under a measuring microscope (in fact, I have also measuring microscope – this was only an old biological one, with a measuring eyepiece). They have the same pitch!

The other part is the optocopler gate. From outside – similar.

As a lens is not made to be disassembled too many times, and i was after 4 disassemblies, i decided to do it in one operation. Desoldered the old, soldering the new, and replacing the plastics too.

THE LENS WORKS!!!!

Canon 24-70 F2.8 aperture cable

Broken aperture coil? Take an aspirine!

During flex cable replacement i have broken a tiny wire in the stepper motor of the aperture module.The is no time for ordering a new one – so let’s repair it!

The wire has a varnish isolation – and approx 0.05 mm diameter…. To get of the varnish you need only an aspirine-pill. Using it with the soldering iron the acetylsalicylic-acid will dissolve the coating, and soldering is possible.

Front lens replacement for 24-105 F4 IS

The owner scratched the front lens of a 24-105 F4 IS. The “official” front lens replacement was much too expensive – so I tried to find a replacement on Aliexpress.

They sell ONLY the front lens of the whole mount – so at first you have to take them apart. This case I was able only by a knife and some brutality. The element itself is also a doublet.

The price on Aliexpress was about 50 EUR – you can find also between 25-100 EUR, I choosed a proven seller for my customer. In such cases the customer has to order the parts by himself. Case the lens would be not good, there would be not too easy to send back in warranty.

The ordered one seemed very similar to the original one (excepting that sits in place with some play, but this can be compensated with some 2K glue.).

But what about the refractive power?!

I checked it with my good old Zeiss lensometer. The difference is probably only the measuring tolerance (1/8 dpt).

After mounting seems to work fine.

Optical adjustment of a slit lamp (ophthalmology)

A slit lamp is the combination of a CMO stereo microscope and a special lamp, with adjustable lighting area, used to examinate the human eyes.

The two eyepieces MUST give the right and left image approx on the same place for the examinators right and left eye, to make a good quality stereoscopic image.

Case the microscope has been damaged, hitted etc, you HAVE TO adjust the two light paths. This can be done in the following way.

Canon EF (body-lens data) protocol

Case You want to see, what happens between the camera and the lens, You will need n oscilloscope, or, better a logic analyser. This is a cheap chinese one – but for our purposes will be ok.

Works for example with the
Saleae software: https://www.saleae.com/pages/downloads , or the
Pulseview software: https://sigrok.org/wiki/Downloads .

Case you need an USB driver, you can use the
zadig: https://zadig.akeo.ie/ driver finder (I can not guarantee, if is virusfree or not – but worked for me.

This is the lens pinout:

You can find some interesting material here:

https://gist.github.com/marcan/858c242db2fc595da1e0bb70a05192fc#file-canon-ef-protocol-notes-md

https://pickandplace.wordpress.com/2011/10/05/canon-ef-s-protocol-and-electronic-follow-focus/

Be careful: the Canon SPI is NON-standard, for ex uses 9 bits, but only the first 8 belong to the data.
Use these parameters:
CPOL=1
CPHA=1
no CS signal

I can not write Python programs – so I hade to solve the conversion in an external Excel sheet, see below.

Good luck.

Button cell battery in Canon

The older cameras use a CR1616 or similar non-rechargable battery, which has to be replaced after a certain time, without opening the camera. These batteries have to supply the internal clock.

In a Canon 2000d, or for ex. in a 6d you will fing an INTERNAL, and RECHARGEBLE battery cell, in my case is a MS614SE.

This battery ha a 3V nominal voltage. But what to do, if the camera has not been used for a long time, and stored without the normal battery? The small cell will discharge. Now the question is: can i leave in, or should I replace it?

The voltage in this case was 0.6 volt. From the datasheet we know, it has the following parameters:

capacity of  3.4 mAh

discharge current 0.015 mA (!!!)

Charging voltage/current: 3.1V/0.1 mA

If you want to test it, you have to charge at first. I desoldered a battery holder from an old 6d board, put a resistor in serial (case we start from 0.6 volt, then with 3.1V charging voltage we have 2.5V on the battery – so we need 25kohm (!) for 0.1 mA.

Let we use 3.2V and 10 kohms, less gentle but quicker.

And it works!

The chinese selector wheel and the good old soviet lathe

As you know from my previous post, the chinese replacement wheel has a geometrical issue, so can not be used.

As I have no time to wait for a new original part (and as the customer would not pay for it….), i decided to take off the outer conical surface on a lathe, and to modify an another old (300d?!) wheel on the inner side, and mounted them together by pressing.

The result is PERFECT. Only 15 minutes of work!

And the two wasted hours for the disassembly/assembly, of course.

Here is the original post: https://canonrepair.wordpress.com/2024/01/29/be-careful-with-replacement-parts/