5 x 7 versus 8 x 10 safelights

[BobUK]

I have been happily using a single 5 x 7 inch safelight, with a 15 watt 240v pygmy bulb in my small darkroom for decades.
In an auction box of photography bits and pieces I found an Ilford S902 8 x 10 safelight filter.
Secondhand commercial safelight lanterns seem to command a fair old price these days. Therefore a d.i.y. safe light filter lantern for 8 x 10 will be my next project.

I have two questions.

Can I expect better lighting with the 8 x 10 and the same 15w pygmy bulb?

And what would be the conventional tungsten bulb/bulbs for an eight by ten commercially made unit on the UK 240v 50hz supply? (How many bulbs, and what power.?)

Thank you in advance for any replies.

 

[F4U]

15W is 15W, no matter the size of the box it is in. You may notice a greater field of light but that's about all. As for an 8x10, whether home made or commercially, you'd still need a 15 watt bulb

 

[MattKing]

You might consider whether a red or amber LED bulb would be a good substitute for the full spectrum incandescent bulb that the safelight was designed for.
There may be advantages with respect to level of usable illumination and heat created. There frequently are advantages with respect to electricity used.
Some LED bulbs are particular about orientation - vertical, horizontal or it doesn't matter - and limited ventilation, so it is important to consider those. And of course you would want a bulb that emits the right "shape" of light, in order that any built in reflector in the housing works appropriately.
Is the safelight just for B&W?

 

[Patrick Robert James]

Once you go to LEDs you won't ever go back. I wouldn't waste time on anything else frankly.

 

[jvo]

Once you go to LEDs you won't ever go back. I wouldn't waste time on anything else frankly.

+++++

 

[xkaes]

Whether it's 5x7 or 8x10 or whatever, you can use 7.5w, 15w or 25w depending on how much light you want. Along with different wattages, you can control the illumination coverage by adjusting the distance between the safelight and the paper -- as well as pointing the safelight in different directions to get nice even illumination. White walls & ceiling help, but in any case, you need to run some tests on your papers.