Question about Macro Photography

[Brian Hirschfeld]

Hi, I have a question about using the Nikon 105mm f/2.8 Macro (latest version) on my Nikon D3s. How can I figure out the length in inches of the in focus part of an image at say f/8, since this lens does't have a focus scale, and figure out where to move the focus ring to for being able to do focus stacking of an object...thanks.

[Dustbak]

This is not an entire answer to your question but having done some focus stacking myself I can assure you that using the focus ring is a sure route to frustration (if great results is what you are after). I can advise to have a look at a macro rail. The Cognisys motorized rail is great for this and even cheaper than the manual one made by RRS.

[Bart_van_der_Wolf]

Hi, I have a question about using the Nikon 105mm f/2.8 Macro (latest version) on my Nikon D3s. How can I figure out the length in inches of the in focus part of an image at say f/8, since this lens does't have a focus scale, and figure out where to move the focus ring to for being able to do focus stacking of an object...thanks.

Hi Brian,

With macro photography one typically uses the magnification factor to calculate the depth of field. For that I use a circle of confusion parameter equal to 1.5x the sensel pitch of my camera for virtually uncompromised focus-stacking with a minimum number of bracketed shots.

For focus-stacking the easiest approach would be to use a focus rail which could then require an almost fixed number of rotations between focus brackets for a given magnification factor (approx. magnification because it changes with each bracket). That approach also works for manual focus lenses. Some stacking software allows to drive the 'focus' (actually the magnification and focus) of AF lenses with fixed increments, but I'm not familiar with the Nikons (Canon shooter myself).

If your camera has Live View and aperture preview then you may actually see how much rotation of the 'focus' ring is approximately required between brackets, but doing this manually becomes very tedious very fast, especially at large magnification factors.

Cheers,
Bart

[theguywitha645d]

I would not worry about doing this mechanically, just use the viewfinder image and shift the focus based on what you see. It will work well--if it works with microscopes, it will work with lenses--and I know it works with lenses because I have done it.

[Michael Erlewine]

I have done lots of focus stacking. Free e-books on this at http://macrostop.com/

I use Nikons (D3x, D3s, D7000) bodies. I have four focus rails, and the best of the lot is the old Minolta that turns up on Ebay fairly often. However, I seldom use rails.

Instead find a macro lens with a long focus throw, 360-degrees or higher. Examples are the Voigtlander 125mm f.2.5 APO lens and the Leica 100mm Elmarit R lens (converted to Nikon mount). The new Nikon 105mm VR has a decent focus throw (270 degrees). Lens with a very short focus throw (90 to 240 degrees) are very hard to use because the tiniest movement of the barrel is often too much. A lens with a long focus throw allows you to turn just a hair and shoot, and then another, etc.

Here I am talking about nature macros that require anything form 12 to 50 layers, and not studio stacking where you may want 150 layers. For studio work, use a rail.

A longish focus throw is just as good as a rail IF you use a sturdy tripod and head. You can see scores of examples at the above mentioned link. The second book listed has specs on over 40 macro and close-up lenses, including their focus throws.

[K.C.]

This is not an entire answer to your question but having done some focus stacking myself I can assure you that using the focus ring is a sure route to frustration (if great results is what you are after). I can advise to have a look at a macro rail. The Cognisys motorized rail is great for this and even cheaper than the manual one made by RRS.

I had never heard of Cognisys so I was interested in checking out their macro rail system. It does look interesting but I am confused as to how you find the $525 Stackshot rail system to be cheaper than the $345 RRS macro rail. Clearly there are significant differences in the systems, one automated, and one not, but that's some fuzzy logic you're using.

Great info in the other posts.

[K.C.]

I have done lots of focus stacking. Free e-books on this at http://macrostop.com/

There is good information in your books but I'm a bit daunted by your total lack of any reference to Canon lenses.

[Bart_van_der_Wolf]

There is good information in your books but I'm a bit daunted by your total lack of any reference to Canon lenses.

Hi,

Well, Michael states that he uses Nikon bodies ...

FWIW, the focus throw (from minimum focus distance at 1:1 to infinity) of the EF-100mm f/2.8L Macro IS USM is approx. 155 degrees, which makes it a fast AF lens, but it's less suited for manual focus stacking without a focus rail. It can be controlled electronically, e.g. by Helicon Remote, if one carries a laptop. There are the first signs of smartphone apps that can also control certain Canon cameras/lenses by using a tablet, which is where the electronic AF is a positive feature.

Cheers,
Bart

[Dustbak]

I had never heard of Cognisys so I was interested in checking out their macro rail system. It does look interesting but I am confused as to how you find the $525 Stackshot rail system to be cheaper than the $345 RRS macro rail. Clearly there are significant differences in the systems, one automated, and one not, but that's some fuzzy logic you're using.

Great info in the other posts.

You are right. Kind of weird logic. I guess I meant the RRS not being even that much cheaper or the Cognisys that much more expensive. I have the Cognisys. The Cognisys is really nice, sturdy and easy in use. Combined with Helicon focus it is a breeze. Using it with something like a Nikon D700 you can have Helicon focus do all the work for you (set how many slices you want and how far the rail has to move up or down). With the MFDB you set the rail over a certain distance and set the number of slices after pressing the 'go' it will move from its start position to the the end position in the amount of slices you have set.

Really nice and easy with great results.

[Chairman Bill]

<snip text> wonderful photo of bee on flowers

Michael,

having shot a number of bees and hoverflies over the summer, I'm aware of just how difficult it is to get a decent focussed photo, before they fly off. How on earth do you manage to focus-stack an image like that?

[Ellis Vener]

Hi, I have a question about using the Nikon 105mm f/2.8 Macro (latest version) on my Nikon D3s. How can I figure out the length in inches of the in focus part of an image at say f/8, since this lens does't have a focus scale, and figure out where to move the focus ring to for being able to do focus stacking of an object...thanks.

Forget the focusing scales and use a magnified Live View view along with a decent loupe like the Hoodman 3X.
I have tried both focusing with the lens and using a finely geared macro focusing rail, and encountered far fewer problems with the stacked image when using a lens' focusing helical as opposed to the focus by moving the camera technique, but I suppose it really depends on what you are photographing. Most of the work I do is still life and product photography , not mushrooms, flowers and insects. Really Right Stuff took the B150-B rail back with no questions asked as it was in pristine condition and within the 30 day period.

I use Helicon Focus X64 software for focus stacking work.

[Bart_van_der_Wolf]

I have tried both focusing with the lens and using a finely geared macro focusing rail, and encountered far fewer problems with the stacked image when using a lens' focusing helical as opposed to the focus by moving the camera technique, but I suppose it really depends on what you are photographing.

Hi Ellis,

Indeed, it depends on the shooting scenario. I have difficulty imagining having to shoot a hundred focus brackets at 5x magnification (26 micron DOF steps) without a focusing rail of sorts. However, with lower magnification factors, and a lens which offers good features (either long manual focus throw or good tethered focusing), then a rail is not necessary. Live View becomes essential in most of these scenarios.

Cheers,
Bart

[Ellis Vener]

Bart ,

I was thinking of you and your work, which is very different than mine,  when I wrote that.

[K.C.]

Well, Michael states that he uses Nikon bodies ...

Yes I'm aware Michael is a Nikon shooter, but his lens of choice is a Voigtlander. So it just seems odd to not toss the Canon 180 macro into the comparisons when including alternatives to the Nikors. Just my point of view. I appreciate the info he is offering.

Indeed, it depends on the shooting scenario. I have difficulty imagining having to shoot a hundred focus brackets at 5x magnification (26 micron DOF steps)...

What are you shooting at that magnification ?

[Ellis Vener]

I believe Bart is photographing microchip processor size "landscapes".

[Bart_van_der_Wolf]

I was thinking of you and your work, which is very different than mine,  when I wrote that.

Hi Ellis,

I think we agree. There is no single best approach, it all depends on the circumstances. Sometimes a focus rail is better, sometimes the lens 'focusing' capability is better. It's alway good to know that there are alternatives available, even if they may be less convenient at the capture stage or in postprocessing. Sometimes even a (under different scenarios) ridiculously narrow aperture has it's merits, although diffraction reduces the ability to enlarge the image and deconvolution sharpening is almost a must.

Cheers,
Bart

[Bart_van_der_Wolf]

What are you shooting at that magnification ?

Hi K.C.,

I shoot all sorts of stuff, from botanical and insect, to more forensic subjects (see examples).

Cheers,
Bart