[reh321]

There is a lot of chatter on this thread and I don't have the current DFA 100mm 2.8 macro so I cant really speak to it much but it seems like a very fine lens. Besides the slowish focusing what is it that is missing? I certainly wouldn't expect a different magnification but who knows.

Pentax themselves talks about ‘purple fringing’.

[bdery]

Besides the slowish focusing what is it that is missing? I certainly wouldn't expect a different magnification but who knows.

Magnification will be the same 1:1. Improvements on PF handling are where the most gains will occur (based on sample images seen online). Even AF is just speculation. It would be a shame if Pentax didn't improve that, but we have no evidence they did.

[JensE]

For instance the Irix 150mm macro (internal focusing) claims a minimum focusing distance of 34cm at 1:1 magnification, that corresponds about 85mm focal length.

The actual value is approximately 91mm at 1:1 and 156mm at infinity, according to a report from Photokina on pentaxians.de, citing IRIX.

Pentax themselves talks about ‘purple fringing’.

I hope coloring of edges outside the focal plane will be reduced as well (LoCA), which could indeed come along with reduced PF. Unless they do a significant optical redesign, which I doubt, the rather unpleasant foreground rendering of highlights (doughnuts), leading to 'mushy' rather than nicely de-focused foreground at 1:1, will likely not go away. The Irix reders much nicer transitions, but comes with great bulk and thus less agility and space for lighting things. The handling of the DFA100WR is still quite a bit more refined (diameter, weight, hood, scales, compatibility with mounts with the aperture simulator - legacy rings, F1.7x converter) and much more robust against flare. With HD coatings, this could become even better. Both are, btw., about equally bright and contrasty wide open, so manual/racking focus works equally well. But the bulk and weight of the Irix limits my session duration with it.

i only use the wr 100 if it's raining, otherwise the laowa 100 has near zero pf wide open and it goes to 2:1... and the end of the lens doesn't stick out past the barrel, so that's nice. only one wr macro in the ff lineup is a real shame, especially since pentax does so much better at f10 and smaller vs. everyone else.

The Laowa has, to my eyes, the best rendering of the bunch and the 2:1 option is great. A stunning optical design and very affordable. It comes at a price though, handling is a lot less refined the both the Irix and Pentax: Non-locking A-setting, way too steep focus to element movement translation (short throw), largely unusable scales, exposed mechanics without front filter, an exposed glass surface with. Put on the flimsy hood and your working distance is gone. Darker viewfinder - it cannot physically be an f/2.8 lens, more an f/3.5. Less than optimal working distance at 1:1 due to retracted front element. The barrel can serve as a hood, but only in very clean environments otherwise you risk getting dust/dirt into the mechanics. (The DFA100WR's hood serves basically the same purpose of protecting the front elemet and is more or less an extension of the barrel for me.) No WR. Lack of SP-like coatings, the original sealing filter is a dust magnet. Longer and heavier than the DFA100WR, less options to light the scene. A lot more prone to flare.


So even if the comparisons show optical advantages of the others, the refined handling, even in details like the hood bayonet (with unfortunately discontinued flash option), make me reach out to the DFA100WR over the other two quite often. Sticking to its size constraint and overall design rather than coming up with something entirely new will retain a lot of the DFA 100 WR's unique strengths and I'm really looking forward to an even improved version of it.

[wkraus]

The Tokina reminds a lot more of the Pentax F 100/2.8 Macro, the first lens released with this optical formula in 1987. With aperture ring (Nikon version), same type of focus limit switch and a focus scale window as the original Pentax version.
SMC Pentax-F 100mm F2.8 Macro Reviews - F Prime Lenses - Pentax Lens Reviews & Lens Database

I hate to do the smart-arse but the F and FA versions are NOT the same design as the D FA and D FA WR, although they are similar. What happened between them was probably what bdery is trying to explain.

[UncleVanya]

I hate to do the smart-arse but the F and FA versions are NOT the same design as the D FA and D FA WR, although they are similar. What happened between them was probably what bdery is trying to explain.

What is different optically? I’ve heard them stated as the same optical design in the past. Curious.

[thibs]

I hate to do the smart-arse but the F and FA versions are NOT the same design as the D FA and D FA WR, although they are similar. What happened between them was probably what bdery is trying to explain.

Not what had been reported till now.
Would you care to elaborate? Much interested. Thanks.

[JensE]

Not what had been reported till now.
Would you care to elaborate? Much interested. Thanks.

They are extremely similar, judging by the lens diagrams on The K-Mount Page | Information about Pentax technology.

The basic design actually dates back to the Pentax-A 100/2.8, the first in the FREE (fixed rear element extension) 100/2.8 macro series. It has a 7 elements in 7 groups design, a 3-element front group, a cemented fixed doublet rear element and two convex middle elements.
In the F/FA evolution, the rear doublet is now air-spaced and a cemented convex/concave pair is added to the middle group. It now looks like a double-Gauss stacked with a triplet, whereas the heritage from the A-versions tells a somewhat different story.


In the DFA incarnation, the lens diameters become smaller (49mm front thread instead of 58mm), the rear surface seems to have become flat instead of slightly convex and the aperture has moved from behind the front group further back. The spacing in the diagram is fairly different, but that may be due to being shown at different focus distances, although the change in the rear element does indicate that there have been adjustments in the design, other than shrinking the outer diameter. It may involve new materials.


That's just the description of the diagrams. What it exactly means and why is beyond my level on knowledge. Obviously, the DFA versions, while still covering the full film frame, may vignette a bit more than the F/FA versions, acceptable because the digital sensors of the time where APS-C only and probably only near infinity focus.

[wkraus]

What is different optically? I’ve heard them stated as the same optical design in the past. Curious.

Not what had been reported till now.
Would you care to elaborate? Much interested. Thanks.

^^^^

JensE has already explained the difference better than I would have been able to.

Edit:

…
In the DFA incarnation, the lens diameters become smaller (49mm front thread instead of 58mm)…

I don’t think that this is the case. The FA version includes a built-in circular lens hood inside the filter thread that is much narrower than 58mm; so the change in filter diameter does not mean that the lens diameter is narrower.

[JensE]

I don’t think that this is the case.

You may be right. I was judging that by the lens diagrams, e.g. the 2nd element in front (convex/concave) looks quite a bit thicker at the edge in the DFA versions. But then spacing to the front element has definitely changed, so that it may actually be the adjusted optical design causing that, rather than the lens being trimmed down.

[UncleVanya]

^^^^

JensE has already explained the difference better than I would have been able to.

Edit:





I don’t think that this is the case. The FA version includes a built-in circular lens hood inside the filter thread that is much narrower than 58mm; so the change in filter diameter does not mean that the lens diameter is narrower.

The front element is highly recessed. The size of that filter thread is much larger in ratio to the glass than the D FA 100 to its filter thread. But it’s possible there are differences.

[lemono]

One interesting thing is that Tokinas version of this lens got an recent update (less than 3 years ago) and now include two Super Low Dispersion lens elements and two Aspherical lens elements. I do not think they have been included on earlier versions Tokinas 100mm macro.
https://tokinalens.com/product/atx_i_100mm_f2_8_ff_macro/

I wonder if it is the same change that will be introduced on the Pentax lens too? And that the actual lens design was made at least 4-5 years ago by Ricoh, but it is not until now that it made sense for Ricoh to start producing it?
I'm no optical designer, but SLD should improve on chromatic aberration, and the aspherical lens elements may be for correcting the use of SLD elements.

It would not be the first time that Tokina released a Ricoh/Pentax design earlier than Ricoh/Pentax.

This is a classic false propaganda of Tokina, which actually reuses the introduction of 1116. As evidence, the later Fe version removed the text of special lens.

https://tokinalens.com/product/atx_i_100mm_f2_8_ff_macro/

https://tokinalens.com/product/atx_i_11_16mm_f2_8_cf/

https://tokinalens.com/product/firin_100mm_f2_8_fe_macro/

You can take a look at the optical performance section. There are surprises

[Fogel70]

This is a classic false propaganda of Tokina, which actually reuses the introduction of 1116. As evidence, the later Fe version removed the text of special lens.

https://tokinalens.com/product/atx_i_100mm_f2_8_ff_macro/

https://tokinalens.com/product/atx_i_11_16mm_f2_8_cf/

https://tokinalens.com/product/firin_100mm_f2_8_fe_macro/

You can take a look at the optical performance section. There are surprises

The FE version is a different lens designed for mirrorless so it is not a later version. As mirrorless usually include correction for CA in software they may not use exact same optical design for the DSLR and mirrorless version of the lens.It may also be that it took much longer to develop the mirrorless lens design as it was a brand new design they did not have previously, so it includes an older lens configuration as the newer design may not have been available when they started.[COLORADO="Silver"]

---------- Post added 10-08-22 at 06:41 ----------

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They are extremely similar, judging by the lens diagrams on The K-Mount Page | Information about Pentax technology.

The basic design actually dates back to the Pentax-A 100/2.8, the first in the FREE (fixed rear element extension) 100/2.8 macro series. It has a 7 elements in 7 groups design, a 3-element front group, a cemented fixed doublet rear element and two convex middle elements.
In the F/FA evolution, the rear doublet is now air-spaced and a cemented convex/concave pair is added to the middle group. It now looks like a double-Gauss stacked with a triplet, whereas the heritage from the A-versions tells a somewhat different story.


In the DFA incarnation, the lens diameters become smaller (49mm front thread instead of 58mm), the rear surface seems to have become flat instead of slightly convex and the aperture has moved from behind the front group further back. The spacing in the diagram is fairly different, but that may be due to being shown at different focus distances, although the change in the rear element does indicate that there have been adjustments in the design, other than shrinking the outer diameter. It may involve new materials.


That's just the description of the diagrams. What it exactly means and why is beyond my level on knowledge. Obviously, the DFA versions, while still covering the full film frame, may vignette a bit more than the F/FA versions, acceptable because the digital sensors of the time where APS-C only and probably only near infinity focus.

The different size of the filters us because the older version of the barrel extended much further out in the front making the lens much longer. When the barrel was made shorter they could use a smaller filter thread. The filter size has nothing to do with the optical formula.
The older design extended so much that there was no need for a lens hood.

The problem with lens diagrams it that they may be too simplified to see all fine details of the design.It is not that you can build a fully working lens from a lens diagram.

[house]

The FE version is a different lens designed for mirrorless so it is not a later version.

But it's just the classic FA100 macro with tube at the end. As so many earch milc lenses. Its not a new design just a new barrel.

[Fogel70]

But it's just the classic FA100 macro with tube at the end. As so many earch milc lenses. Its not a new design just a new barrel.

The mirrorless version use a completely different barrel and use different type of AF, and have focus-by-wire manual focus. So there is a lot that is different between the mirrorless and DSLR version of this lens other than just the lens mounts. I expect it to be more work to design the mirrorless version from "scratch" than to make a new revision of the existing DSLR lens.

[Serkevan]

I expect it to be more work to design the mirrorless version from "scratch" than to make a new revision of the existing DSLR lens.

It depends. Sometimes modifications are much harder than starting from scratch, if there are pre-existing constraints that you have to respect.