Understanding macro rails

Just bought that first macro lens? Post here to get helpful feedback and answers to any questions you might have.

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lartamax
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Understanding macro rails

Post by lartamax »

Hi,
I am totally new to macro rails and very limited macro experience. I am using the following,
Canon r6,
Canon rf 100mm f2.8 1.4-1
NISI macro rail.
I have a couple of very basic questions.
Subject will be a wasp.
After focusing on the front of the wasp. Do I refocus every time I move the camera forward on the rail. Or is this un-necessary as the distance will change and overlap.
With a shallow depth of field how do I get even the wasp in full focus. Do I need a separate stack starting on the left of the subject, then down the centre and again down the right of the wasp.
I am using Zerene trial version but have nothing but failures so far. Most likely I am not using short enough increments.

Thanks,

John.

rjlittlefield
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Re: Understanding macro rails

Post by rjlittlefield »

John, welcome back!

Checking your history of postings for context, I see that I last chatted with you in 2016, at a time when you were asking how to get to 2:1 or better.

That's a fair bit of time, but since you now say very limited macro experience, I'll assume that you have not been doing much macro in those 5 years, and sort of take this from scratch.

I suggest to start by reading https://zerenesystems.com/cms/stacker/d ... or_subject . That is on the Zerene Stacker website, titled "Tutorial #2: Using a Macro Lens on a DSLR", the section titled "Method #2 — Focusing by Moving the Camera or Subject".

Addressing your specific questions...
Do I refocus every time I move the camera forward on the rail.
No, do not change focus. Only move the camera.
With a shallow depth of field how do I get even the wasp in full focus.
The whole idea of focus stacking is to combine a lot of pictures that each have shallow depth of field, into a single picture that has a large depth of field.

So, you get the wasp in full focus by going one step at a time for a lot of steps.
Do I need a separate stack starting on the left of the subject, then down the centre and again down the right of the wasp.
No, don't do that. That would be an advanced technique that we call "stack-and-stitch". It is a combination of focus stacking and side-by-side panorama stitching, much more difficult than focus stacking alone, and not appropriate for you at this time.

Instead, you should start by choosing a magnification that is low enough for you to fit the entire wasp inside the camera frame at one time. With your Canon R6 camera, this will probably require something around 1X. Then you will shoot a single stack, using a step size that is small enough for the in-focus portions to overlap from one step to the next.

The required step size can be estimated by using Table 2A at https://zerenesystems.com/cms/stacker/docs/tables/macromicrodof .

At 1X and a setting of f/11, the table suggests a step size of 1.1 mm. This will be about 1 turn of the screw on a NiSi NM-180 rail.

I am using Zerene trial version but have nothing but failures so far. Most likely I am not using short enough increments.
If you have further difficulties, then please post images that show us what you're getting.

Instructions on how to post images can be read at viewtopic.php?f=20&t=41917 .

--Rik

lartamax
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Re: Understanding macro rails

Post by lartamax »

Hi Rik,

Thank you for the breakdown on what is probably an extremely basic method.
Yes I got sidetracked with weddings and the like but now having retired from all that I can get back to styles of photography are more for my own satisfaction.
Thanks again,

John.

rjlittlefield
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Re: Understanding macro rails

Post by rjlittlefield »

You're very welcome. I wrote Zerene Stacker, so I have had a lot of practice answering these sorts of questions.

One thing I forgot to mention: be sure to set your lens on manual focus. Sometimes people forget this detail, and the camera auto-focuses for each movement of the rail. You can probably imagine that this does not produce the desired result.

--Rik

lartamax
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Re: Understanding macro rails

Post by lartamax »

Thanks again Rik,
hopefully get a go at this all tomorrow.

John.

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