Ilford Film reciprocity

Can you make the example on the sheet work, i.e. 10seconds at a factor of 1.31 = 20.4?

On your calculator are you doing this:
10^1.31

It should just work
 
Ok so that worked :s I can only think I was pushing the wrong button the whole time :(. I just want a reliable way to work out exposure for pinhole
 
I got it wrong the first time as well, they probably should have made it a bit clearer in the doc.

Once you know what youre doing though this way is a lot easier than having to carry around little graphs or cobbled together tables of exposure times to lookup. Good luck with the pinholes
 
I created a Numbers spreadsheet a couple of years ago that used the original factor. Hadn't realised they'd updated it for each film. I'll update it with a film selector and the new values. More than happy to share it if you're interested. Probably won't be until Monday.
 
I used the Ilford factor for FP4+ on Pinhole Day and found it worked just fine.
 
raathistle said:
I got it wrong the first time as well, they probably should have made it a bit clearer in the doc.

Once you know what youre doing though this way is a lot easier than having to carry around little graphs or cobbled together tables of exposure times to lookup. Good luck with the pinholes
Click to expand...

this looks clear to me, i cant really see what else they could of done. the equation is written out and what button to press!

"
This uses the equation Tc = Tmp


Where Tm is the metered (indicated) time and Tc is the corrected time. P is a factor calculated following a range of exposure times

Enter into the calculator the metered (indicated) time in seconds.

Press the xy button and enter the factor for the product from the table below and then the = button. "
 
Have you tried using the Pinhole Assist app?
 
niko said:
Press the xy button and enter the factor for the product from the table below and then the = button. "
Click to expand...

Which is fine if your calculator app has an xy button, as lets face it most people aren't going to be taking actual calculators out in the field with them. Mine for example (stock android on a pixel) doesn't have that button, you have to use the ^ button.

RaglanSurf said:
Have you tried using the Pinhole Assist app?
Click to expand...

that looks like a nice App Nick, if only it was available on Android. I'll have to have a look around for an alternative :(
 
raathistle said:
Which is fine if your calculator app has an xy button, as lets face it most people aren't going to be taking actual calculators out in the field with them. Mine for example (stock android on a pixel) doesn't have that button, you have to use the ^ button.
Click to expand...
I've got a Samsung S5 phone and its inbuilt calculator becomes a scientific one when you turn the phone to landscape rather than portrait. I think it might actually say yx rather than xy, but it works just the same.
 
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raathistle said:
Which is fine if your calculator app has an xy button, as lets face it most people aren't going to be taking actual calculators out in the field with them. Mine for example (stock android on a pixel) doesn't have that button, you have to use the ^ button.



that looks like a nice App Nick, if only it was available on Android. I'll have to have a look around for an alternative :(
Click to expand...
yet that is a good point, but I do think the Ilford doc is very clear, I think it's great that they put this imfo out in such thing easy format to Use
 
niko said:
yet that is a good point, but I do think the Ilford doc is very clear, I think it's great that they put this imfo out in such thing easy format to Use
Click to expand...

I agree, it's so much more useful than any of the other methods we used to get :)
 
raathistle said:
that looks like a nice App Nick, if only it was available on Android. I'll have to have a look around for an alternative :(
Click to expand...

Yeah, I really think they're missing a trick with it not being available on Android.
 
Peter B said:
I've got a Samsung S5 phone and its inbuilt calculator becomes a scientific one when you turn the phone to landscape rather than portrait. I think it might actually say yx rather than xy, but it works just the same.
Click to expand...
I never knew about turning the phone landscape to get a scientific calculator, works on mine too. So won't have to resort to my sliderule with the log-log scale on the back.
 
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