Stone or Petrified Wood?

[xpatUSA]

Inspired by Odd's "Tree disguises as stone, or perhaps the other way around" I'm asking about this:







Found it out on our gravel-surfaced road near Bellville, Texas, but no idea where it was quarried.

It's about 4x6" overall (10x15cm), by the way.

The end view leans me toward 'rock' but any opinion is welcome ...

[Shadowman]

Nice efforts, the third has best texture but the DOF limits the impact.

[JohnRostron]

First, once wood becomes petrified, it would then be a rock! (Petro means rock or stone.)

I do not think it is petrified wood. It looks more like alternating layers of sediment compressed over time. You get these on, for example, on lake bottoms or deltas. You might like to google 'Varves'.

John

[xpatUSA]

Nice efforts, the third has best texture but the DOF limits the impact.

Thanks John, I did try focus-stacking on them all but was in too much of a hurry so ended up picking the "best" of each stack. The stacked end view did not align well during focus stacking and was pretty bad. Might try the rail next time and see if my apps can align those better. Also shoot with a longer lens (Sigma 105mm macro) from a greater distance would help.

[xpatUSA]

First, once wood becomes petrified, it would then be a rock! (Petro means rock or stone.)

LOL

I do not think it is petrified wood. It looks more like alternating layers of sediment compressed over time. You get these on, for example, on lake bottoms or deltas. You might like to google 'Varves'.

John

I tend to agree, especially as much of SE Texas is a alluvial plain. Thanks for the suggestion re: "varves": it does seem to fit the bill!

[Shadowman]

Thanks John, I did try focus-stacking on them all but was in too much of a hurry so ended up picking the "best" of each stack. The stacked end view did not align well during focus stacking and was pretty bad. Might try the rail next time and see if my apps can align those better. Also shoot with a longer lens (Sigma 105mm macro) from a greater distance would help.

John,

Did you use a DOF calculator for the settings used?

[xpatUSA]

John,

Did you use a DOF calculator for the settings used?

Please call me Ted.

Yes, I did:



My own spreadsheet using magnification as input for close-up work.

[Shadowman]

Please call me Ted.

Yes, I did:



My own spreadsheet using magnification as input for close-up work.

Ted,

Thanks for the info and the correction.

[xpatUSA]

Nice efforts, the third has best texture but the DOF limits the impact.

John, I had another go at stacking. Here's the first view stacked. Very much mo' better DOF I think ...



Also I used a 70mm and shot from further away . . . helps to cheat.

[Shadowman]

Ted,

Much better, focal length/distance does make a difference.