# Focus Stacking – lens choice for landscape photography



## bod (May 29, 2017)

I have been inspired to start using focus stacking in landscape photography after reading an informative article by Lloyd Chambers on the Zeiss site lenspire.com – http://lenspire.zeiss.com/en/depth-field-challenges-bypass-limits-focus-stacking-near-far-macro-landscape/ 
The article gives some advice on the choice of lenses for focus stacking. 
One aspect that is discussed is the extent to which a lens exhibits focal length change with changing focus distance. It is stated that:
“_Lenses that minimize changes in focal length and distortion with focusing are strongly preferred (zoom lenses are prone to both types of changes, particularly at close range)_.”
“_Many macro lenses change focal length with changes in focus, some greatly. A change in focal length when focusing changes the image size (magnification), which makes for more of a mismatch for the stacking software to correct_.”

I have the very good ZE 50 f/2 makro planar classic lens and am trying to evaluate how suitable it is for focus stacking. I expect that macro lenses can exhibit more focal length change with focus position when they are focussed closer at macro level magnifications. I expect also that for lenses of a given focal length there will be differences in the amount they focus breath depending on the exact details of their lens designs. My question then is if the ZE 50 f/2 is compared with a non-macro 50 prime but at the same focus distances are there any other reasons why the macro should not perform similarly as regards focal length shift with focus change?

I would be grateful for any advice on this question or in general what lenses you use for focus stacking in landscape photography.


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## pwp (May 29, 2017)

Sounds like you're onto it regards lens choice.
You'll also need this (or similar)
https://www.bhphotovideo.com/bnh/controller/home?O=&sku=1124144&gclid=CPn1_pad1soCFQ18vQoduRkMlQ&is=REG&A=details&Q=

-pw


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## Mt Spokane Photography (May 29, 2017)

Ideally, a bellows unit works best, there are some lenses that work better than others too. Many use macro rails, and they work if you are not extremely particular.

Here is a article that evaluates the macro rails. There are some good older ones that cost much less.

Michael Erlewine also mentions the best Macro lenses for focus stacking, and the best techniques and software. It provides better alternatives for some of the popular methods of stacking.

https://lensvid.com/gear/choosing-the-best-focusing-rail-for-macro-photography/


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## geekpower (May 30, 2017)

do you really need macro rails for landscape work? i read OP as saying he wanted to stack shots at say, 3', 20', and infinity, not 1/16" apart.


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## Mt Spokane Photography (May 30, 2017)

geekpower said:


> do you really need macro rails for landscape work? i read OP as saying he wanted to stack shots at say, 3', 20', and infinity, not 1/16" apart.



The principle is the same. To avoid changing the size of the image as you move focus, you need a lens that does not do this, or a rail. You obviously do not need a bellows.


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## Valvebounce (May 30, 2017)

Hi Mt Spokane. 
Thanks for answering this, but I'm curious as to whether a 2 1/2inch movement would be sufficient to account for focus breathing on a landscape shot even with one of the better lenses recommended? 
What length of movement might be required if 2 1/2" is not enough? 

Cheers, Graham. 



Mt Spokane Photography said:


> geekpower said:
> 
> 
> > do you really need macro rails for landscape work? i read OP as saying he wanted to stack shots at say, 3', 20', and infinity, not 1/16" apart.
> ...


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## BeenThere (May 30, 2017)

As a camera body feature, should Canon offer Automatic focus stacking multi-shot mode. User picks near and far points, and the number of frames, then camera auto adjust focus between the two selected points and shoots all in between frames automatically. Nice to have feature for landscape, and maybe macro shooters.

Or, bracket focus, where user's focus point is bracketed a user selected distance automatically.


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## sanj (May 30, 2017)

Thx for posting.


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## Mt Spokane Photography (May 30, 2017)

Valvebounce said:


> Hi Mt Spokane.
> Thanks for answering this, but I'm curious as to whether a 2 1/2inch movement would be sufficient to account for focus breathing on a landscape shot even with one of the better lenses recommended?
> What length of movement might be required if 2 1/2" is not enough?
> 
> ...



Graham, I do not stack landscape, so I am not sure about a rail. I have a bellows for macro when on a tripod, but mostly, I use my 100L handheld for close focus. 

Landscape images are my weak point, I do not have a good eye for the composition of them. I admire those who do. The license of my stacking software has expired, so I don't do that any more. Not enough use to justify dedicated software as I get older and do less of that sort of thing.

The problem is that a thread like this gets me interested again, then I spend money and time. I have too many things going.


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## bod (May 30, 2017)

Hi pwp and Mount Spokane. Thanks for the posts and advice. I have not yet tried focus stacking for macro or close up work but it is something I plan to try and I will aim to get some macro rails and study the link further.


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## bod (May 31, 2017)

geekpower said:


> do you really need macro rails for landscape work? i read OP as saying he wanted to stack shots at say, 3', 20', and infinity, not 1/16" apart.



You are correct that my interest is in focus stacking in landscape photography and these distance illustrate the range of focus movement. I think in view of the distances involved it is necessary to refocus the lens in order to create a series of stacked images and therefore it is desirable to have a lens which exhibits minimal focus breathing.

I put some distances into the simple lens formula for a 50mm focal length lens as shown in the attached image.




.

This illustrates that the nearer the lens has to focus on the object the greater the lens needs to move to retain the image on the sensor.

In reality a camera lens has multiple elements and: 
“_Because most current lenses use an internal focus system. That means instead of moving the whole lens barrel back and forth to focus, a small group of elements inside the lens are moved. The advantage of this is that the small group of lenses is smaller and lighter than the whole lens, so it can be moved faster with less power to give you faster AF. It's also possible to minimize aberration changes with focus distance by moving elements around. Of course if you move some of the elements around within the lens and leave others in place, you change the optical parameters of the lens. One of those parameters might well be the effective focal length (or angle of view if you prefer). The effect can vary from lens to lens, depending on the design.” Bob Atkins Photography_

Since a macro lens has to focus at much closer distances than a non-macro lens I imagine it is more prone to focal length shift at these close up distances when being used for macro photography. Hence I think the statement in Lloyd Chambers article that “_Many macro lenses change focal length with changes in focus, some greatly_”

But when shooting stacked images for landscape photography a 50 mm macro will be operating at the same focus distances (e.g. 500 m, 7m, 1m) as a 50 mm non-macro lens. So my question now is are there any fundamental reasons here why the two lenses should not perform similarly as regards focal length shift with focus change (focus breathing)?


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## NancyP (Jun 6, 2017)

Why not a tilt-shift lens? It all depends on the subject of course - but unless your landscape is 100% motionless, focus stacking is a PITA. Any wind, combined with water or leaves, can be problematic.


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