Building A Professional Grade Shutter Tester

[ic-racer]

I ordered both of these and, I'm not sure which was which. One was defective and the other is in my light source now. Maybe they are both the same.

 

[ic-racer]

This is the exact sheet I ordered. It is glossy, whereas the instructions ask for a mat finish. I found out "P95" refers to this mat finish. So, if I were to order again I might look for the 2447 with the P95 designation.

 

[ic-racer]

Thank you, do you have an Aliexpress link for LED#4 from post #83? Also, the "diffuser "Silky White" 88x88 6mm thick" seems to be hard to find. Do you have a link for this one, too?

Edit: Finally found a 6mm frosted acrylic sheet. I'm not sure if the quality will do compared to your high quality acrycast sheet: https://aliexpress.com/item/1005002538429057.html?

That one looks too 'clear'.

 

[ic-racer]

 

[ic-racer]

The screws I got were just a little too long, so I put washers under them so they did not push through the front.

 

[FM2]

I could get something with 70% transmission. Both surfaces have a satinated finish though. The git hub discussion mentions 60% transmission. Should be managable via voltage regulation.

Thanks again!

@all Here is the link to the deleted git hub discussion:

srozum/film_camera_tester · Discussions · GitHub

Explore the GitHub Discussions forum for srozum/film_camera_tester. Discuss code, ask questions & collaborate with the developer community.

web.archive.org

 

[ic-racer]

Thanks for the Wayback machine link. Too bad my extensive build thread was not picked up.

One issue people had was the power supply needing to be to high to make up for light loss from the diffusing panel. They thought this might damage the fan.

In my experience with these little fans, they are both inexpensive and ok with higher voltage. One could even put a resistor in line to the fan if one was worried. I don't think any of the other electronics are bothered by 13 volts or even more.

 

[ic-racer]

When my light source was finished, my Sekonic 588 meter read perfectly on all the EV levels (after adjusting the light output voltage at level 12 per instructions) and I declared that as my standard.

 

[FM2]

That's what I'm going with as well. As long as I can regulate the EV output via voltage, slight deveations from the stated 60% transmission value should be ok – and in my case I will probably have to tune it down a bit.

Slowly worries about details come creeping in: Drilling perfect 90° holes for the sensors might be a challenge without a drill stand

 

[ic-racer]

Without a drill press, I drilled from the outside in. Then countersunk the holes from the inside. I made a little jig from the end of the drill to make sure the front side did not get too thin.

 

[FM2]

Looks good, I'll try that. Do you know where to get the SIC553-04/PIC0903SL sensors? I found the TSL237 but the others are hard to find.

Based on your posted pciture, I found these ones:

https://aliexpress.com/item/1005003480690394.html?

I guess you just plucked the sensors off the pcbs. How did you confirm that these are indeed the SIC553-04/PIC0903SL sensors?

 

[ic-racer]

Yes, the sensors just unplug from the sockets.

As I recall, it was easy to figure out if the sensors were operating reverse and I switched to the other firmware without issue.

I actually built my unit twice. First I just put it together to see if it worked. Then I re-did it for sustainability. For example, the first time I soldered the Nano straight to the Shield.
When I re-built it, I attached a socket so I could swap out the Nano easily if I wanted to change firmware.

 

[aconbere]

Hi! Another builder putting together the parts. The BOM lists an LD24AJTA LED driver, with an RCS of 0.091 OHM. There are a ton of these units on AliExpress, most look like this (linked). The description indicates that there is a resistor that can be replaced in order to limit current. It's not clear to me what resistance value the unit ships with.

My question is whether or not folks are purchasing the correct 0.091 ohm replacement and swapping that in.

Thanks!

 

[ic-racer]

Yes, I replaced the resistor on theLED driver board.

 

[aconbere]

@ic-racer After your hunt for appropriate rotary encoder and push buttons which ones did you end up going with? I'm closing in on having all of these parts ordered but there are a few still giving me issues.

 

[ic-racer]

I suspect the rotary encoders on AliExpres work but I went with Bourns brand as I had used them in the past. The only issue is clockwise rotation makes the EV numbers smaller. No big deal since I usually use my left hand on the knob.
Bourns may make one that encodes the other way, but Mouser only carries one version that I could see at the time.

 

[ic-racer]

I also got tactile switches from both AliExpress and Mouser.
I went with the ones from Mouser. I don’t recall the brand, Omiron or NKK. They did have 4 tiny plastic feet on the back that I easily removed with an Xacto knife.

 

[aconbere]

Ugh so many questions - the BOM in the wiki lists parts for a "Light Unit #2 Rev.4" but the pcb assets list only a directory "light_unit_2" which has a BOM file "BOM_PCB LightUnit2 Rev.3.csv" (noting the Rev.3 here) and the parts disagree with the wiki. I'm inclined to believe the Gerbers and BOM but also curious if folks have also noticed this.

 

[ic-racer]

This was asked and answered but not captured by Way back machine. I believe the answer was merely an insignificant change in capacitor values.

 

[aconbere]

@ic-racer Ah, I've been trying to reference the archived Q&A as much as possible but it seems like the last capture in February left a lot of details out

 

[ic-racer]

I read all the posts and answers, but did not write it down, though I still remember most.

 

[FM2]

Ugh so many questions - the BOM in the wiki lists parts for a "Light Unit #2 Rev.4" but the pcb assets list only a directory "light_unit_2" which has a BOM file "BOM_PCB LightUnit2 Rev.3.csv" (noting the Rev.3 here) and the parts disagree with the wiki. I'm inclined to believe the Gerbers and BOM but also curious if folks have also noticed this.

I also went with the "BOM_PCB LightUnit2 Rev.3.csv" file – the wiki does not even state which resistor goes where. Let's hope for the best..

 

[ic-racer]

I also went with the "BOM_PCB LightUnit2 Rev.3.csv" file – the wiki does not even state which resistor goes where. Let's hope for the best.

I used the parts from the BOM file (Rev 3), rather than the WIKI (Rev 4). In that case, resistors locations for R1-R4 printed on the PC board would be:
R1 = 2k
R2 = 2.2k
R3 = 4.7K
R4 = 4.7K

C1 = 220uf
C2 = 470uf

Resistor

 

[ic-racer]

This what I built. You can see the two capacitors (440uf in front and 220uf in back).
You can see the replacement 0.091 ohm resistor on the driver board.
Also shown are the resistors R4 and R3, the same value.

 

[ic-racer]

I bent the legs on this connector to fit into the holes of the PC board. Thicker wires from the power supply should go straight to the LED unit.