www.photomacrography.net :: View topic - Aperture (f-number) stacking?
www.photomacrography.net Forum Index
An online community dedicated to the practices of photomacrography, close-up and macro photography, and photomicrography.
Photomacrography Front Page Amateurmicrography Front Page
Old Forums/Galleries
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
Aperture (f-number) stacking?

 
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Macro and Micro Technique and Technical Discussions
View previous topic :: View next topic  
Author Message
kit1980



Joined: 18 Aug 2016
Posts: 122
Location: Bellevue, WA, USA

PostPosted: Thu Feb 01, 2018 4:58 pm    Post subject: Aperture (f-number) stacking? Reply with quote

What if instead of changing focus plane, we change the aperture, and then merge the photos with usual focus stacking software? I think this may result in increased depth of focus without introducing diffraction artifacts to the part that is in focus, with "main" part that really in focus to lead the viewer to.

I have this idea for some time, but haven't really tried it. Have anyone tried this? Does it sound it can work?
_________________
Omax microscope with Nikon CF objectives
Olympus OM-D E-M10 Mark II camera
https://www.facebook.com/sdymphotography/
Back to top
View user's profile Send private message
Lou Jost



Joined: 04 Sep 2015
Posts: 2165
Location: Ecuador

PostPosted: Thu Feb 01, 2018 5:18 pm    Post subject: Reply with quote

I also have been thinking about that, but with an eye to using shots at successively larger apertures all in the same stack, using the initial small-aperture shots to fill in the parts that are usually washed out by haloes from edges that are in front of them.
_________________
Lou Jost
www.ecomingafoundation.wordpress.com
www.loujost.com
Back to top
View user's profile Send private message Visit poster's website
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 18790
Location: Richland, Washington State, USA

PostPosted: Thu Feb 01, 2018 5:21 pm    Post subject: Reply with quote

kit's idea should work OK. Taking a few shots with smaller apertures is a well established way of finishing stacks, to make the background less blurred without affecting the in-focus slab.

--Rik
Back to top
View user's profile Send private message Visit poster's website
ChrisR
Site Admin


Joined: 14 Mar 2009
Posts: 7651
Location: Near London, UK

PostPosted: Thu Feb 01, 2018 5:55 pm    Post subject: Reply with quote

Kit - I played around with that some time ago, after finding I got more detail from a smaller aperture, where it was otherwise hidden behind out of focus haze. That was happening in steep sided depressions, where the sides caught the cone of light when using a wider aperture.

Alignment problems arose:
one is that stacking software usually goes through an alignment phase. You have to make sure they're all aligned the same, - or not at all;
even when you do that, closing an aperture often shifts the focus a little, which is confusing;
and detail from a small aperture frame will sometimes appear in a different place from were it is on a sharper, large aperture frame.

The upshot was that I had to exclude almost everything from the small aperture frames. It was only the one at the back end of the subject (as Rik explained) and just parts here and there, when there was a detail obscured by OOF blur which the stacker had left behind.
_________________
Chris R
Back to top
View user's profile Send private message
Dalantech



Joined: 03 Aug 2008
Posts: 401

PostPosted: Fri Feb 02, 2018 1:42 am    Post subject: Reply with quote

rjlittlefield wrote:
kit's idea should work OK. Taking a few shots with smaller apertures is a well established way of finishing stacks, to make the background less blurred without affecting the in-focus slab.

--Rik


I've seen shots there the last frame was taken with the lens stopped down, and it looked really good. Those sharp transitions between what's in and out of focus are distracting, but stopping down the last frame smoothed it out.
_________________
My Gallery
My Blog
Macro Tutorials
Back to top
View user's profile Send private message
ChrisR
Site Admin


Joined: 14 Mar 2009
Posts: 7651
Location: Near London, UK

PostPosted: Fri Feb 02, 2018 3:12 am    Post subject: Reply with quote

Yes, it can be good wherever you aren't doing a complete stack. You need something like 3-4 stops down though, so a lot more light. Then edit out anything from the image which is sharp from in front of that last slice.
_________________
Chris R
Back to top
View user's profile Send private message
Lou Jost



Joined: 04 Sep 2015
Posts: 2165
Location: Ecuador

PostPosted: Fri Feb 02, 2018 4:57 am    Post subject: Reply with quote

Here is where I think it would pay off to stack a series at steadily increasing f-stops, each over the whole range of depth that was desired, rather than tacking on one very different image at the end.

Example- Single shot at f/32, a couple over the whole range of interest at f22, then the whole range at f16, then the whole range at f11, etc, all in the same stack so the slices get draped on properly to a single consistent master image, so that any haze from out-of-focus edges will be rejected or minimized or easily removed in retouching.

I have never tried this though, don't know if it will work.
_________________
Lou Jost
www.ecomingafoundation.wordpress.com
www.loujost.com
Back to top
View user's profile Send private message Visit poster's website
ChrisR
Site Admin


Joined: 14 Mar 2009
Posts: 7651
Location: Near London, UK

PostPosted: Fri Feb 02, 2018 6:51 am    Post subject: Reply with quote

Yes it did work where there were those"deep depressions". I think the only post I did about it was the first- http://www.photomacrography.net/forum/viewtopic.php?t=20238


Some lenses improve contrast a little on stopping down as well, which can male things look better even if there's strictly speaking, less resolution.
_________________
Chris R
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Macro and Micro Technique and Technical Discussions All times are GMT - 7 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group