Shot with extension tube

PedroYoung · Jun 22, 2019

So I shot a series of pics trying to focus on the same chalice mouth using first a single 36mm extension tube, then stacking a 20 mm on top then added the 12mm (so total of 68mm on the final shot. Then tried to crop the first and last shot the same. It was really hard to focus that last shot (lighting was pretty low, mostly blues). Kept the settings the same on all shots (f/7.1 , ISO 200, with aperture priority setting).

First with 36mm

peelx36mm by Peter Young, on Flickr

Then with both 36mm and 20mm

peelx36x20mm by Peter Young, on Flickr

Then with all 3

peelx36x20x12mm by Peter Young, on Flickr

Here is the crop of the first shot

peelx36mmcrop by Peter Young, on Flickr

And the same (sort of) of the last shot

peelx36x20x12mmcrop by Peter Young, on Flickr

And here's what the camera looks like (and how close to the glass I was on the final shot).

Untitled by Peter Young, on Flickr

Mark3 · Jun 22, 2019

It seems like you are getting better depth of field with the ext tubes ...do you find that to be true?

Mark3 · Jun 22, 2019

It seems like you are getting better depth of field with the ext tubes ...do you find that to be true?

Mark3 · Jun 22, 2019

It seems like you are getting better depth of field with the ext tubes ...do you find that to be true?

PedroYoung · Jun 22, 2019

Mark3 said:
It seems like you are getting better depth of field with the ext tubes ...do you find that to be true?

I’m not sure if that’s the reason.

maroun.c · Jun 25, 2019

with stacking tubes and especially with less lighting focusing becomes an issue, I switch to manual focusing most of the time and also use a focusing rail that allows you to move the camera to the front or back to focus. I can also see some distortion/blurr which is caused by not being perfectly perpendicular to the glass and also from camera motion. at those extended magnification ratios the slightest mostion will show on your picture. make sure your tripod is sturdy and use a shutter release to minimize any motion caused by pressing the shutter button as well as mirror lock if your camera offers it to minimize micro motion caused by the mirror opening and closing.

PedroYoung · Jun 25, 2019

maroun.c said:
with stacking tubes and especially with less lighting focusing becomes an issue, I switch to manual focusing most of the time and also use a focusing rail that allows you to move the camera to the front or back to focus. I can also see some distortion/blurr which is caused by not being perfectly perpendicular to the glass and also from camera motion. at those extended magnification ratios the slightest mostion will show on your picture. make sure your tripod is sturdy and use a shutter release to minimize any motion caused by pressing the shutter button as well as mirror lock if your camera offers it to minimize micro motion caused by the mirror opening and closing.

Yeah, in order to get this chalice, which is on the bottom, I have to angle pretty severely which causes some blur. I always use manual focus with preview zoom which allows me to pick a spot, zoom in, then adjust manual focus. I also use a remote trigger for the shutter release. Have not tried a focusing rail (haven't seen one). I'll look into it, thanks for the tip.