LED safelight switch on question

[Dani]

I got this LED light today and to my surprise it has a 2 second switch on delay and the switch off has a delay too. There's no difference if I use the dimmer or connect it straight to the power adapter. I was hoping it'd be instant on/off like the S11 bulbs I was asking about here https://www.photrio.com/forum/threads/superbrightleds-s11-bulb-question.187272/ but it's actually annoying when using with the timer.

Anybody using this with a timer? Same experience?
Thank you!

 

[koraks]

Anybody using this with a timer?

'this' being...that anonymous strip in the center of your photo? What kind of product is it? Is it specifically intended for darkroom/photo use? Have you tried contacting the manufacturer?
Sorry, no. But any generic (red) led strip with a cheap switching power supply will turn on more or less instantly and turn off fairly quickly as well unless the power supply is oversized dramatically. You might need to apply additional filtering with e.g. rubylith film to make it safe though.

 

[Dani]

You’re right! I should have put more info. The light bar is marketed for darkroom use by certain vendor, the wavelength is 632nm https://www.superbrightleds.com/mor...s/linear-led-light-bar-fixture-100-lmft/3277/

The issue is the power supply. I’m using a different one and now there a barely noticeable delay. Still there but not as bad. I contacted the place but their tech customer support was somewhat lacking in knowledge.
Thank you for the reply

 

[koraks]

The issue is the power supply.

Yeah, makes sense. Good that you've been able to find the problem.

The led bar itself looks pretty neat, but be sure to test thoroughly that it doesn't fog the paper. Those 620nm leds often have secondary emission peaks in the green part of the spectrum that wreak havoc on paper. I didn't see the mention of these being intended specifically for darkroom use and I would be surprised to have found it in the applications list; virtually no manufacturer at all lists this kind of thing, except for dedicated photography stores. Prices are usually significantly higher as well.

 

[Dani]

I'm wondering if there's a better power adapter that would give me immediate switch on when using a timer but for now it'll work.
The link I posted is for the website where the vendor that sells it for darkroom use gets them from (dedicated photography store). I'll make sure to test it fully.

 

[koraks]

I'm wondering if there's a better power adapter that would give me immediate switch on when using a timer but for now it'll work.

Looks like any generic 12V power supply should do; fortunately, these are cheap enough to test a few until you find one that suits your needs. If it's only this one led strip, it can be a fairly small unit. In fact I'd recommend not to oversize it. Get one that will go up to 1A or so, or perhaps 1.5A. It will still be plenty big enough for a single one of those strips. Probably a fairly simple 'wall-wart' type would do fine.

 

[Dani]

That one that I first got was 12v 0.4A 12W, the one that is giving me better results is 1.5A, I was thinking of getting a 2A but I think I'll just use my 1.5A. Thank you!