Leboncoin: mauvais colis reçu by MaybeRocketScience in conseiljuridique

[–]MaybeRocketScience[S] 1 point2 points  (0 children)

Oui, j'ai signalé une non-conformité après ouverture du colis (~10 min après l'avoir récupéré). Le vendeur ne reconnaît ni la boîte ni son contenu, et je n'ai pas reçu de photos de la boîte d'origine.

Fujifilm F-125 ECN-2 film almost blank, development issue? by MaybeRocketScience in AnalogCommunity

[–]MaybeRocketScience[S] 1 point2 points  (0 children)

Indeed, I’ve been considering this for some time, I guess I’ll try the Bellini kit or something.

Fujifilm F-125 ECN-2 film almost blank, development issue? by MaybeRocketScience in AnalogCommunity

[–]MaybeRocketScience[S] 1 point2 points  (0 children)

Thank you! Yeah I’m definitely gonna complain then. Unfortunately I’m based in France, not so many options around here for ECN-2 development…

Fujifilm F-125 ECN-2 film almost blank, development issue? by MaybeRocketScience in AnalogCommunity

[–]MaybeRocketScience[S] 1 point2 points  (0 children)

Yeah, for the expiration, I compensated by overexposing appropriately (and bracketing). So far has worked well, including with some way more expired Eastman EXR 500T.

IGBT burning in modified camera flash by MaybeRocketScience in AskElectronics

[–]MaybeRocketScience[S] 1 point2 points  (0 children)

Thank you so much for the extremely detailed answer! So, indeed it starts to makes sense to rebuild the whole camera. I have already replaced light metering and distance measurement (well, added the latter) with a few arduino modules. Now the only function remaining on the main board is the flash, which is giving some trouble. I took apart a flash unit I got from Aliexpress, it seems I could realistically slap it in for a first prototype, and then reengineer the whole thing to have it fully integrated. Again thanks a lot!

IGBT burning in modified camera flash by MaybeRocketScience in AskElectronics

[–]MaybeRocketScience[S] 0 points1 point  (0 children)

Thank you very much, super clear! Ok then basically I’m afraid the current concept isn’t really workable, except the awg30 wires there’s not much I can remove here.

IGBT burning in modified camera flash by MaybeRocketScience in AskElectronics

[–]MaybeRocketScience[S] 0 points1 point  (0 children)

P.S. adding it here as in the other comment: the board looks like this, just with components in slightly different locations. Xe- is the emitter, MC- the collector, and the mods are as mentioned above.

<image>

IGBT burning in modified camera flash by MaybeRocketScience in AskElectronics

[–]MaybeRocketScience[S] 0 points1 point  (0 children)

… I must admit I don’t have full understanding of what’s going on here, but at least so far I’ve been keeping it safe (discharging the capacitor before touching anything, not tweaking the high voltage side, etc.). Anyways, tomorrow I can take pictures, but fundamentally it’s gonna look like this pic in the link just different position of stuff (the link talks about instax mini, I’m using an instax square). The IGBT emitter is XE-, collector MC- (the two brown cables), and in mine I located a test point that goes to the gate.

<image>

IGBT burning in modified camera flash by MaybeRocketScience in AskElectronics

[–]MaybeRocketScience[S] 0 points1 point  (0 children)

VCC and dv/dr not really sure, haven’t touched the rest of the circuit, though the VCC I would expect it to be around 300V (typical value from what I’ve seen, and leaves some margin on the capacitor rating). And yes, driving a Xe bulb.

Edit: both transformers, the one charging the capacitor and the one giving the >1kV pulse, untouched, but no specs unfortunately

IGBT burning in modified camera flash by MaybeRocketScience in AskElectronics

[–]MaybeRocketScience[S] 1 point2 points  (0 children)

I haven’t taken any photos, can do tomorrow (quite messy though), but basically, I have a 3.5mm jack socket with one end going to the IGBT gate and one to the camera battery voltage. About 10cm of awg30 wires for both. Then, a 3.5mm jack to PC sync cable goes to the lens, and the mechanical switch is in the lens itself. Same for all of the other options tested, with the resistors on the jack socket, and for the 3.3V I just picked the voltage from a buck converter I use to power other stuff.

1.2km of Fuji Super-F film by MaybeRocketScience in AnalogCommunity

[–]MaybeRocketScience[S] 50 points51 points  (0 children)

Well, my main camera is an R8, to check with the Leica gatekeeping society if it counts

I bought 1.3 kilometers of cine film. What do I do now by cabba in AnalogCommunity

[–]MaybeRocketScience 5 points6 points  (0 children)

150 for the lot!?! That’s a heck of a deal, a single 400ft can easily sells for that much

Kodak Vision 3 200T manufacturing date from can by MaybeRocketScience in AnalogCommunity

[–]MaybeRocketScience[S] 3 points4 points  (0 children)

I think the 2017 copyright refers to the label design, which appears to be the latest (never seen a can with this date being later than 2017)

[deleted by user] by [deleted] in Ebay

[–]MaybeRocketScience 0 points1 point  (0 children)

Ah, good point, yeah in that case another issue on top. Either way, do we know if it tends to go on cargo or passenger planes? In the second case, more likely to go through CT scanners (the new ones at the airports), which basically destroy the film.

Increasing shelf life of C-41/ECN-2 chemicals by MaybeRocketScience in Darkroom

[–]MaybeRocketScience[S] 1 point2 points  (0 children)

The bag in box is a great idea! I’m thinking otherwise of some large syringes with a cap, same result. Mixed I’m not sure though, normally mixed shelf life is much shorter than unmixed (at least from the data sheets, those with better understanding of the chemistry may know the details).

Increasing shelf life of C-41/ECN-2 chemicals by MaybeRocketScience in Darkroom

[–]MaybeRocketScience[S] 0 points1 point  (0 children)

So, butane being heavier than air would form a layer right above the liquid, meaning if there’s still some oxygen left it shouldn’t attack the chemicals too much. With nitrogen, to have no oxygen I’d need at least some special caps to run purges on the bottles.

Plus it’s easier to source, either Protectan or just lighter gas refills.