Building A Professional Grade Shutter Tester

ic-racer · Apr 29, 2023

Also obtained a real Cree XHP70.2 for testing:

albada · Apr 29, 2023

Where did you get the LED and the Cree-brand star? I didn't know Cree made stars. The only sellers of stars I've used is ledsupply.com and cutter.com.au, and neither are Cree-brand.
Also, did you solder the LED onto the star yourself?

I bought some stars from Cutter that are made of copper, not aluminum, for the Cree XE-G lamps. Good stuff!

ic-racer · Apr 30, 2023

I got the real CREE XHP70.2 LED from Mouser electronics, but it does not come on a star.

My impression is that all the stars that read "CREE" are fake. I don't think Cree makes or sells those stars.

I took the fake LED off a star and put a real Cree XHP70.2 in its place.

Real Cree on the LEFT and fake on the RIGHT:

ic-racer · Apr 30, 2023

The creator of the projects indicates a fake Cree is needed (Epileds XHP7070.2), and indeed when I installed the real Cree, the EV values were slightly off. The high values with the real CreeXHP70.2 are too high by about 0.4EV and the low values are too low by about the same amount.

This is the image posted on GitHub, of two fakes with the correct one (Epileds XHP7070.2) on the right.
I have tried 3 different suppliers of Epileds XHP7070.2 LEDs, but have not received any that look like either of those:

albada · Apr 30, 2023

ic-racer said:
This is the image posted on GitHub, of two fakes with the correct one (Epileds XHP7070.2) on the right.

Correct fake? The idea that you must find the correct fake would be amusing if it weren't evidence of all the dishonesty out there.

I don't have a hot plate, so I used a piece of scrap aluminum on the stove:

After the paste melted into solder, I'd rub the back of the star over the wet sponge to cool it. This approach works with stars, but I'd be reluctant to try it with a circuit board.

rcksdty · Apr 30, 2023

I forgot to mention on the rotary encoder issue you where having. I had gotten mine from Amazon and they work fine. You just have to desolder them from the boards they come on and resolver them on the tester function board. Link below:

rcksdty · Apr 30, 2023

Also the Cree LED I got from aliexpress have been working ok.

https://www.aliexpress.us/item/3256802737871439.html?spm=a2g0o.order_list.order_list_main.147.39b818022k9f1W&gatewayAdapt=glo2usa&_randl_shipto=US

ic-racer · Apr 30, 2023

rcksdty said:
Also the Cree LED I got from aliexpress have been working ok.

https://www.aliexpress.us/item/3256802737871439.html?spm=a2g0o.order_list.order_list_main.147.39b818022k9f1W&gatewayAdapt=glo2usa&_randl_shipto=US

This is my experience so far:

LED #1: "Epileds" faulty on arrival, got refund (below)

LED #2 "Epileds" stopped working after about an hour (below):

LED #3 Real Cree XHP70.2 did not match the firmware settings. Too bright at EV16 and a little too dim at EV5 (below):

LED #4 Currently installed. Seems to be working OK but again, does not match the picture of the one from Github (below):

The reason for the concern over the "correct" LED is that color temp really matters. I have no idea the color temp of the recommended LED or the one I have.

ic-racer · Apr 30, 2023

albada said:
Correct fake? The idea that you must find the correct fake would be amusing if it weren't evidence of all the dishonesty out there.

I don't have a hot plate, so I used a piece of scrap aluminum on the stove:

View attachment 337263

After the paste melted into solder, I'd rub the back of the star over the wet sponge to cool it. This approach works with stars, but I'd be reluctant to try it with a circuit board.

Nice. My wife won't let me in the kitchen to do stuff like that so I did mine on the gas BBQ out side.

ic-racer · May 1, 2023

I will try to borrow a DSLR and use that to measure the light temp of my LED.

In the GitHub WIKI for this project it lists the color temp as "2800K and 5000K" and recommends the device setting of EV12 as the calibration point. I would suspect it to then read about 2800K at EV5 and 5000K at EV 16 or 17.
Presumably it would be close to 4700 at the EV12 calibration point if the device follows the information presented in the graph below:

ic-racer · May 1, 2023

I measured my LED with the DSLR and it is more like 2500k to 2800k. I don't know where he comes up with the 5000k, maybe a misprint.

ic-racer · May 1, 2023

Building "Sensor #1."

rcksdty · May 2, 2023

how did you locate the holes for sensor 1?

rcksdty · May 2, 2023

what size foam did you use

ic-racer · May 2, 2023

rcksdty said:
how did you locate the holes for sensor 1?

I did not show these because there is an error in my pictures. If you put the smooth side of the PC board on the front of the sensor plate (like my picture below), the holes will be on the wrong diagonal. You either have to turn the PC board over so the components lie against the face (and it is a little wobbly) or drill from back to front. Since I don't have a tiny drill press, I needed to drill from front to back to ensure the holes are the correct spacing. It is a given that without a drill press, the holes will not go straight through.
Yes, I only noticed my mistake after drilling the first 3, so I wound up with 5 holes, but no big deal for the extra holes. I can get a new piece made if needed.

ic-racer · May 2, 2023

You can see the holes in the wrong location here.
For gluing, I taped it, then glued the two center locations, and removed the tape before gluing the perimeter. So the glue would not seep under the tape and make a mess.

ic-racer · May 2, 2023

rcksdty said:
what size foam did you use

Mine measured 4.25mm.

ic-racer · May 2, 2023

M2.5 tap for the screws.

ic-racer · May 2, 2023

ic-racer · May 3, 2023

ic-racer · May 3, 2023

Sensor #6 for AE and EE exposure testing:

ic-racer · May 3, 2023

It is pretty much finished. Just waiting on my cable strain reliefs for the connectors and the buttons. Next is to make the "Sensor #3" for leaf shutters.

rcksdty · May 3, 2023

if you need switch covers for the switches I have those ...extras. Also if you need stuf 3d printed let me know. contact me @ rcksdty@gmail.com

ic-racer · May 3, 2023

rcksdty said:
if you need switch covers for the switches I have those ...extras. Also if you need stuf 3d printed let me know. contact me @ rcksdty@gmail.com

I only ordered some black ones but they won't be here until the end of the month from China. Do you have some colorful ones?

rcksdty · May 3, 2023

ic-racer said:
I only ordered some black ones but they won't be here until the end of the month from China. Do you have some colorful ones?

Building A Professional Grade Shutter Tester

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