Photographic reference scale

Nature Talk
1

Some time ago I wondered if my observations were lacking a scale so I made a small reference inspired in the forensic ones and wanted to share it. The size is small enough to carry in most phone cases (10x5cm). I use it to measure fishes, small insects and under a petri dish for background. You can dowload it here or here ready to print.
What are your thoughts? Do you find it usefull?

https://forum.inaturalist.org/t/fingers-in-photos/30145
https://forum.inaturalist.org/t/encouraging-a-sense-of-scale-in-photos/4147

2

A scale is good. But in some areas it will not be always obvious and this should also include mm., cm, lines or inches.

3

This does look very useful, thanks for sharing! May I also recommend the Life to Scale project? :)

4

After printing, compare to a real ruler to make sure it came out at the correct size.

5

Good job! I think it’s great that you created a custom scale. Is it paper with lamination? In cases like a petri dish, where scale dimensions cannot be inferred from the ruler marks, maybe adding a note stating that grid has 5 mm spacing would be helpful?

6

Thankfully, if the markings are visible on the ruler edge, it’s easy to infer the scale.

If there are 10 divisions (spaces between dark marks) between major marks, it’s a metric/mm ruler 99.9% of the time, whereas if there are 2, 4, 8, 16, 32, etc. divisions it’s imperial/inches.

Still waiting for that 0.1% observer who carries around an imperial machinists ruler that divides inches into 10ths, that would be confusing for sure!