Practicing the craft: Stone sculptor

[JBW]

This is a 28 shot stack with 28 individually set focal points (hope that's the right terminology) Not wishing to add in possible errors caused by subject movement I shot stones. I did adjust the focal points manually and used the wireless shutter release. I don't think I moved the camera when making adjustments.

Natural light and stacking in Fiji. Shutter speed of 0.1s with an F/7.1. My usual Tamron 90mm lens.

[NorthernFocus]

Hey, Brian. Considering the technique that you describe I'd expect the entire subject to be tack sharp. However there appear to be some soft spots in the area indicated by the red circle. Particularly at the top and bottom of my circle. Since the image is stacked you must have missed focus on a couple of frames?

[JBW]

Hey, Brian. Considering the technique that you describe I'd expect the entire subject to be tack sharp. However there appear to be some soft spots in the area indicated by the red circle. Particularly at the top and bottom of my circle. Since the image is stacked you must have missed focus on a couple of frames?

Me? Miss focus? Weather permitting I'll try again tomorrow.

[NorthernFocus]

Me? Miss focus? ...

I know it's a shocking thought. And with my tired old eyes I was loathe to mention it. But the soft spot stayed put as my gaze wandered around the image so it seemed real. I suppose the rocks will wait around for another take...

[Stagecoach]

A good subject for practicing with Brian

Some observations, comments and things to consider;

It appears from the caterpillar and this stack that your stacking software is working well so your main aim now is to perfect your procedure. That means confidently determining your required near and farthest focus planes (points is ok) and then deciding your procedure to divide and adjust this into the number of divisions you want equally.

This may mean 'marking' your focus barrel in some way (tape?) at the two extremes (which we would normally just go past), or noting distance scale readings. Then comes the tricky part, how do you divide this angular distance into say 25 divisions?

On my lens the rotating focus barrel has long straight longitudinal serrations and a white spot on the non-rotating part adjacent to these and it's simply a matter of counting the number of serrations (ridges) moved each time.

Good luck

[JBW]

A good subject for practicing with Brian

Some observations, comments and things to consider;

It appears from the caterpillar and this stack that your stacking software is working well so your main aim now is to perfect your procedure. That means confidently determining your required near and farthest focus planes (points is ok) and then deciding your procedure to divide and adjust this into the number of divisions you want equally.

This may mean 'marking' your focus barrel in some way (tape?) at the two extremes (which we would normally just go past), or noting distance scale readings. Then comes the tricky part, how do you divide this angular distance into say 25 divisions?

On my lens the rotating focus barrel has long straight longitudinal serrations and a white spot on the non-rotating part adjacent to these and it's simply a matter of counting the number of serrations (ridges) moved each time.

Good luck

I did mention the need to get into the tech side... big big sigh. I just took a look and there are no barrel markings and the distance scale is set up for portrait distances. But there will be a way.

[Stagecoach]

I did mention the need to get into the tech side... big big sigh

Brian, there is no need to get 'techy' about this

Whilst there is loads written along with clever calculators available online that work out with respect to DoF how many 'slices' and their spacing you need for a certain depth range at a certain aperture my own experience suggests these are not essential.

I'm pretty confident that if I was to do more focus stacking and record/compare a number of results I would come up with the info that with my lens using the serrations method it would give me 'something like';

a) at f/11 use 1/2 serration intervals

b) at f/22 use 1 serration intervals


If you have no lens barrel serrations or its markers are too far apart simply draw some lines spaced equally at say 4 mm apart on a length of masking tape and wrap it around the focus barrel. See how it goes and modify accordingly.

Edited with more realistic figures found in my notes..............

[Stagecoach]

I just took a look and there are no barrel markings and the distance scale is set up for portrait distances. But there will be a way.

I may be wrong Brian but a quick search showed this as the 272E model. If so, the serrations I mentioned are almost identical to what's on my Nikon 105. Standing/sitting behind the camera I just align what I have shown with the white arrow to the white spot.

[xpatUSA]

I may be wrong Brian but a quick search showed this as the 272E model. If so, the serrations I mentioned are almost identical to what's on my Nikon 105. Standing/sitting behind the camera I just align what I have shown with the white arrow to the white spot.

So are these serrations considered linear as regards distance of the focal plane from the sensor?

I ask because the marks on my Sigma (sorry) lenses are decidedly non-linear.

[Stagecoach]

So are these serrations considered linear as regards distance of the focal plane from the sensor?

No Ted. But, for the purposes of focus stacking have served me well.

I know exactly where you are coming from and I could have sold you an adaptor should you require the accuracy of a logarithmic scale had you been the unfortunate owner of Nikon or Tamron lens

I ask because the marks on my Sigma (sorry) lenses are decidedly non-linear.

Now that is useful Ted, I would like to see pic.

[ajohnw]

Brian are you just using Fiji aka ImageJ with plugins to stack or another application as well? I've only seen it used with enfuse to do the actual stacking.

Are there any detail on the web on doing it entirely with Fiji - if you are?

John
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[JBW]

Brian are you just using Fiji aka ImageJ with plugins to stack or another application as well? I've only seen it used with enfuse to do the actual stacking.

Are there any detail on the web on doing it entirely with Fiji - if you are?

John
-

asking if I am just stacking in Fiji is like asking is this just a single malt But the answer is yes I am. And here's a link to lots of information on how to do it.

[ajohnw]

People might find this link more informative if they are interested Brian

https://www.google.co.uk/search?clie...k1.mNpPty7mpQo

I've had imageJ about for a long long time and last time I looked the focus stacking plugin usually but not always worked. Fiji seems to be a beta rewrite or spin off of imageJ so wondered if it came ready for focus stacking which is why I asked.

ImageJ itself still seems to still be hosted on a .gov site as it always has been.

https://imagej.nih.gov/ij/


Having it around for a long long time hasn't done me much good. It's intended for use by extremely capable image processing people of a different type to the usual photo person.

Doh - no idea how that became underlined.
John
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[xpatUSA]

No Ted. But, for the purposes of focus stacking have served me well.

I know exactly where you are coming from and I could have sold you an adaptor should you require the accuracy of a logarithmic scale had you been the unfortunate owner of Nikon or Tamron lens

Excellent!

Now that is useful Ted, I would like to see pic.

Here is the well-respected 70mm f/2.8 DG model:



Pardon the shaky hands



Needs two pics because of it's 240 degrees travel - a delight to a manual-focusing troglodyte.

[JBW]

People might find this link more informative if they are interested Brian

https://www.google.co.uk/search?clie...k1.mNpPty7mpQo

I've had imageJ about for a long long time and last time I looked the focus stacking plugin usually but not always worked. Fiji seems to be a beta rewrite or spin off of imageJ so wondered if it came ready for focus stacking which is why I asked.

ImageJ itself still seems to still be hosted on a .gov site as it always has been.

https://imagej.nih.gov/ij/


Having it around for a long long time hasn't done me much good. It's intended for use by extremely capable image processing people of a different type to the usual photo person.

Doh - no idea how that became underlined.
John
-

Fiji is ImageJ on steroids with all the bells and whistles already installed. Unless I'm mistaken it is hosted on a government site because it was developed with government funding.

It was certainly developed for people involved in scientific research. Most of Fiji is way beyond my ken but I do enjoy those bits and pieces that fit my needs.