Garden Spider

[derekphil]

This fella has taken up residence outside my study window. Common garden spider, about an inch across with legs extended.
This is focus stacked, 25 images, and I'm quite happy with the result, but I'm still learning the technique, and do not think I'm at the optimum yet.

[Geoff F]

Looks good to me. It is so difficult to get a clear web like that one.

[xpatUSA]

Quite a beast! What prompted the choice of stacking or were you just practicing? No EXIF, so it's hard to guess ...

[Shadowman]

Nice shot.

[DanK]

It's a nice shot, and I don't see artifacts, but 25 images is overkill. Given that you were shooting with the critter parallel to the sensor, there isn't much depth. The only real depth is from the hump of the abdomen and the ends of the legs. It shouldn't require more than a few images to stack this, and with far fewer than 25, you should be able to get into focus the ends of the legs that are now out of focus.

To make this concrete, the following image is a single image, not stacked at all, taken at f/13:



Now, the bottom is flatter, which means less need for stacking, but on the other hand, I was a lot closer, which means a smaller depth of field.

So my bottom line is that you can have a lot more focusing difference between shots and therefore far fewer shots to stack.

[vaez]

well done

[derekphil]

Dan
Thanks. I'm still struggling a bit with this. I have a Fuji XT-2, which has auto focus built in, and I've been using that. I just tried again, two images, one 25 exposures controlled by the camera, and one 5 exposure with me changing the focus between shots. I can see hardly any difference. If anything, I would say the 5 esp (the slightly darker one) is better.
The lens is a Fuji 60 mm macro, and the DoF seems quite shallow. I was about 6 inches from the spider.

[xpatUSA]

The lens is a Fuji 60 mm macro, and the DoF seems quite shallow. I was about 6 inches from the spider.

Pardon me butting in but, assuming say f/5.6, those settings only get you 1mm DOF. Even Dan's f/13 only gets you 2mm. (numbers rounded to nearest mm by my calculator). Shooting at Dan's f/13 and 1 ft would get you 10mm, quite an improvement, eh?

In other words, shooting distance is highly significant in close-up work.

This from about 1-1/2ft:



Depth of ship engraving is about 15mm. Focused on the text "Ship Susan" so the DOF was more than 15mm of course.

[DanK]

The DOF is actually hard to calculate because the effective focal length of macro lenses decreases as you get close to minimum working distance.

I never stack bugs because I am not steady enough--although orb spiders could be an exception, as they stand still for long periods. That's why I shot the spider at f/13. A tiny bit of diffraction is more than offset by the increased DOF.

I stack flowers, and when I do, I typically shoot no narrower than f/7.8 or 8.0 to maximize sharpness. In the case of shallow flowers, I can often get away with 3-8 shots. Moderately deep ones take more; for example, this one is 14:



In rare cases, when a flower is very deep, I will go above 20, and I just found one that is more than 30. However, this too may be more than I needed. I don't want to run the risk of completing a stack and finding that one or two gaps are too large, so I err on the side of too many.

[xpatUSA]

The DOF is actually hard to calculate because the effective focal length of macro lenses decreases as you get close to minimum working distance.

Yes, I have written two calculators for that very reason. My macro one works on magnification. It says about 0.4mm for 60mm at f/5.6 and 1:1 mag. Not sure the OP was at exactly 1:1 though.

[xpatUSA]

The DOF is actually hard to calculate because the effective focal length of macro lenses decreases as you get close to minimum working distance.

By the way, are you sure about that, Dan? My Sigma true macros increase. Also see:

"When focusing close, the effective focal length gets longer ..."

https://www.whatdigitalcamera.com/te...ens-work-60974
.

[DanK]

By the way, are you sure about that, Dan? My Sigma true macros increase. Also see:

"When focusing close, the effective focal length gets longer ..."

https://www.whatdigitalcamera.com/te...ens-work-60974
.

Oops. You're right.