[bdery]

What does "deliver a surprisingly dynamic bokeh" mean?

A dynamic bokeh is not desirable. It means it's not creamy, but has features and patterns in it.

Further, the image that follows is of a bird, but it's several sections later in the review.

Thanks for pointing this out, there's an image missing. I'll look into it with Adam.

Thank you for naming the files after the respective lenses! SO much easier to keep them straight that way.

a pleasure! It helped me too

Secondly I really have to agree with the quote above. Re. sample images from the Tamron .... only one macro shot ?! It should be the other way around

I happen to agree. I had the Tamron for testing for less than a week, and many outdoors macro shots turned out less than satisfying under close review (I DID mention it was quite windy :P ) The Pentax is my own lens, so I could dig in my archives to find good macro samples.

Since the purpose of the review is to compare the lenses, I think the most helpful samples are the comparative ones, and you do have quite a few of those. And for general samples of the Tamron, well,. the forums are full of them

I do think, however, that many people (me included) will get these lenses for the dual purpose of a great macro AND a fast short tele, that's why I took pains to discuss this aspect too. There are much less samples to be found of the lenses used as tele.

In any case, thanks for commenting and more so for reading!

[olenl]

I wonder if the really deep lens placement on Tamron is an issue when using lens filters like Reynox DCR150?

Does it really matter how far the Reynox is placed from the front lens element? Does it affect the maximum magnification or quality of the images?

Also, does DCR150 work well with Pentax 100mm WR? I've found some images from Tamron 90 with this addon but not from Pentax 100mm WR...

[olenl]

And by the way, I have seen an older version of Pentax 100mm Macro lens in the local store for about $530 and wondering if I should get it... It has no WR but the optical scheme is probably the same... Is it worth extra $270 to go for WR version instead? That's about what it will cost me here. Are there any good comparisons between the two?

[bdery]

I wonder if the really deep lens placement on Tamron is an issue when using lens filters like Reynox DCR150?

I can't answer that without testing, sadly.

Does it really matter how far the Reynox is placed from the front lens element?

It could, but it depends on how the Raynox is designed, and I have no first-hand knowledge of it.

Also, does DCR150 work well with Pentax 100mm WR?

Same answer

And by the way, I have seen an older version of Pentax 100mm Macro lens in the local store for about $530 and wondering if I should get it... It has no WR but the optical scheme is probably the same... Is it worth extra $270 to go for WR version instead? That's about what it will cost me here. Are there any good comparisons between the two?

The newer, WR version sells for about 600$. You you mean you found a DFA-100 for 350$? I think if the difference is 70$, then the WR and newer design is worth it. If the difference is more important, it becomes a matter of choice. To me a small, WR lens with a metal body is very useful, but many people have shot fantastic images with the older models. I have used a FA50 macro before, and it was fantastic too.

[Anvh]

One of the most desirable attribute of a macro lens is a smooth, creamy background blur. The Tamron lens has nine straight aperture blades, while the Pentax has eight rounded blades. The optical designs of the lenses are also different. Do these differences account to anything noticeable in real life?

The differences, when discernible, are minimal. The following images illustrate a representative example of busy out of focus areas taken with both lenses. Very close inspection shows that the rounded blades do create shapes that are more completely circular, but the nine straight blades come so close it’s almost a draw. The transition from in-focus to out-of-focus is also very smooth in both cases.

Lets bust the myth once and for all now....
The shape of the aperture does not effect the bokeh!

Bokeh is about how the light is distributed in the "blur disk".
The aperture does have an effect on the shape but that isn't bokeh.
It's for the most part the lens design that shapes the bokeh.

A pefect corrected lens gives an even distribution of light on in front and after the focus point.
Then you've lenses that are over or under corrected, these give "nisen" (donut) bokeh fore or after the focus point and on the other side it will give you the soft/smooth bokeh.

If you don't believe me compare the DFA100 normal and WR version, they give the same bokeh while one has rounded blades and the other not.
Bokeh

[Unsinkable II]

Great review. Thanks. I've been pondering which of the two to get. If the price difference were just US$100 then I'd get the Pentax every time. Unfortunately, here in HK the Pentax is more expensive than the US (nearly $700) whereas the Tamron is way cheaper (less than US$350).

[kenafein]

Bokeh is about how the light is distributed in the "blur disk".
The aperture does have an effect on the shape but that isn't bokeh.
It's for the most part the lens design that shapes the bokeh.

Bokeh

The shape is pretty important. 6 blades produces hexagonal shapes in the bokeh for example(which I like sometimes), so maybe that doesn't matter much once the aperture is near a perfect circle.

[jimr-pdx]

A very nice review. Folks that go to the user-review section should note that several Tamron comments relate to the non-Di version; that would only amount to a change in coatings I believe but could influence a decision. The older SP 90/2.8 that I own shows little of the CA that the review copy has, and it's a non-Di copy; after the test I gave it a spin on a bright day just to verify.

[Anvh]

The shape is pretty important. 6 blades produces hexagonal shapes in the bokeh for example(which I like sometimes), so maybe that doesn't matter much once the aperture is near a perfect circle.

Thats the thing, aperture does not shape the bokeh or influence it, it's the lens design that does.
What you're talking about is the shape of the blur disk and you only see that shape with the highlights so it's not that super important and it does not make or brake an image.

Bokeh is about how the light is distrubuted in the blurdisk and that greatly define how the out of focus blur looks.

[Opethian]

Thanks for posting this review. This type of lens isn't exactly something I will be purchasing anytime soon, but I now know which one I'll be getting (the WR).

[bdery]

Lets bust the myth once and for all now....
The shape of the aperture does not effect the bokeh!

Yes it does.

Bokeh is about how the light is distributed in the "blur disk".

Bokeh is a very subjective concept. It generally refers to the "quality" of all the out of focus area. If you want to propose a new definition, we might discuss it

(donut) bokeh

That occurs almost exclusively with mirror lenses.

aperture does not shape the bokeh or influence it, it's the lens design that does.

Well, without wanting to brag, my job title is senior optical designer, and I can confirm that the quality of the out of focus area is influenced by many factors, one of which is the design of the aperture stop.

the shape of the blur disk and you only see that shape with the highlights so it's not that super important and it does not make or brake an image.

That's an opinion, and one that many people will disagree with.

[jimr-pdx]

Thanks for posting this review. This type of lens isn't exactly something I will be purchasing anytime soon, but I now know which one I'll be getting (the WR).

Not to force a macro lens on anyone, but note that these are both excellent portrait and general short-tele lenses. I found a great deal on mine despite my not being a full-time shooter of bugs, flowers or stamps, and it will get plenty of use at the near-infinity end. It's the best lens I have ever owned. Don't let the word 'macro' set your mind and skills on a specific path into the world of tiny things.

[jimr-pdx]

I really enjoyed the review, but for the record I find very little CA in my copy of the Tamron*. I looked online generally and the Tamron is commonly criticized for being fringey, so bdery's copy is not alone. I have tried mine on several torture images that some of my other lenses have failed quite badly; even wide open I have no reason to criticize. So that particular issue with the Tamron 90 may or may not match up with any single copy of the lens.

*Mine is the pre-Di version, which should have no bearing on the results - my understanding is that only the coatings were changed between the two, not the optics.