Reciprocity & Bellows Extension

[Ian-Barber]

Have I got this the right way round ?

When working with bellows extension, do you add the number of stops to the metered exposure and then calculate the reciprocity.

Example:
Metered exposure = 1 second
Lens: 150mm
Bellows extension: 300mm

Exposure including bellows extension: 4 seconds
True exposure: (what ever 4 seconds is for the film being used)

 

[Keith Haithwaite]

I think this makes it clear Ian.

http://www.timlaytonfineart.com/blo...alculate-bellows-factors-magnification-ratios

 

[Ian-Barber]

Thanks Keith

 

[Ian Grant]

You can make a card scale for your most used lenses, in my case I used a fine black indelible marker to indicate the increased exposure in 1/3 or 1/2 f stops with my 150mm lens.

Ian

 

[martin-f5]

using a android mobile phone you can use inverse

https://apkpure.com/inverso/com.printerattic.inversoapp

have it and like it

 

[David M]

Reciprocity last.

 

[PaulBJE]

I think this makes it clear Ian.

http://www.timlaytonfineart.com/blo...alculate-bellows-factors-magnification-ratios

Thanks for the link Keith. I will find that blog very useful.