See post #8 to #16 for revised worksheet, and post #22 for a final revision. The final version is available for download at GitHub, link in post #31.
I decided to make a new exposure worksheet and thought that I'd have a look at what others have done. However, it looks like exposure worksheets have never been the subject of a thread and only come up occasionally in passing. I guess that interest, or lack of it, in this thread will demonstrate either that the subject has been overlooked or that it's too simple and obvious to spend time discussing
I've attached my new one and I'm more than open to criticisms and suggestions. I'd also love to see others'. I use a worksheet to avoid exposure errors, but I also like having a record that I can look back on and learn from.
My new one could be printed on a legal size sheet of paper (8.5"x14"), but I plan to use it on an iPhone or iPad. I've filled out the attached copy with an invented example to show how it works. Some comments...
Note that the final exposure is entered at the top of the worksheet, not at the end.
I've used mathematical formulas for bellows compensation (step 1) and reciprocity failure for Ilford films (step 4). Both calculations are extremely simple. For me, the bellows compensation formula is more appealing and faster than the various workarounds based on f-stops. The forum home page article on bellows compensation, from 1998, contains this statement: "[This method] requires no fancy gadgets to purchase nor algebraic formulae to memorize." Twenty-four years later, smartphones and iPads, with high resolution screens and plenty of computing power, are ubiquitous. The formula for bellows compensation involves elementary math that takes a few seconds on a smartphone calculator.
Calculating reciprocity failure directly is faster than using the Reciprocity Timer app, which I find kind of clunky. It's a one-step process, applying an exponent, which Ilford provides, to the time value that exists before taking into account reciprocity failure. There's an xy button on my phone's calculator designed specifically to do this kind of calculation. Ilford has some caveats about the calculation, which of course need to be kept in mind, but the caveats also apply to Reciprocity Timer. If I want to add comments, for example if I choose to deviate from the calculation, the worksheet row will expand if necessary to accommodate added text.
The centre filter and polariser (step 2) are new and I need to get some experience with them before settling on values. There are a couple of filters for black and white that I may add to this step. They would have to go on this lens's rear element, which is something that I need to experiment with. The following thread covers that issue: Using a Neutral Density Filter on a Rear Lens Element.
Regarding step 3 on neutral density filters, I'm aware of the fact that opening an aperture by 7 stops has nothing to do with reality. The idea is to take into account the option of parceling out the 7 stops to a combination of aperture and time. In addition to the 4-stop and 7-stop, I may add a couple of lower value ND filters to this section of the worksheet. Again, this is a rear element issue.
I abandoned the idea of having one worksheet for all of my lenses while making this. I think that I'll wind up with two three versions to cover eleven lenses.
In case anyone is interested in the mechanics, I used Apple Pages to make the worksheet. I could also have used Apple Numbers. It's just a table with two columns.
I plan to try out the worksheet this weekend. I hope to confirm that it isn't too time-consuming to use. It works very well on an iPad, and seems OK on my phone, which has a fairly large screen, in landscape mode. Another option is to use the voice memo app on my phone to record the data and fill in the worksheet at the end of the day.
Curious to learn how others handle this.
REVISED, SEE POST #8
Exposure Worksheet
The text is a bit small, presumably due to a forum upload limitation. However, it can be zoomed in on if desired.
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