Volcano tourists near crater spewing lava - GIF

[CharlesWaugh]

It a 'long zoom lens' - as a professional photogrpaher I can tell you they could have been 100 yards away.
A long lens stacks everything up to look almost in a flat plane, this is due to the magnification factor.
Also, with only one 'eye' there is no parallax to tell distance with.

[mklotz]

It a 'long zoom lens' - as a professional photogrpaher I can tell you they could have been 100 yards away.
A long lens stacks everything up to look almost in a flat plane, this is due to the magnification factor.
Also, with only one 'eye' there is no parallax to tell distance with.

I'm familiar with the foreshortening effect of telephotos. However 100 yards is hardly separation enough if a breach allows water to enter the caldera and cause a steam explosion. Also, it's a deathly short headstart if a lahar starts coming their way. Pompeii is five miles from Vesuvius.

I don't know what a safe distance is and I'm fairly sure the folks in the video don't know either. Erring on the conservative side seems a good idea.