[xjjohnno]

I'd love to see a comparison between my $1300 125mm Apo Lanthar and one of those $2500 Apo Lanthars to compare the quality.

[mano]

I currently own both the Sigma 105 and the DA 100 WR (got lucky on ebay...) and, like everybody else here it seems, can recommend them both.
I personally prefer the Pentax' warmer colours and softer bokeh, which is why I will probably sell the Sigma to a friend, but that does not mean the Sigma delivers anything but incredible IQ.

[Laurentiu Cristofor]

Stick to Pentax or Sigma - the Pentax if WR and build are worth the price difference for you. Tamron too if 90mm is fine. Vivitar Series 1 is a notch below these as it has some problems with purple fringing and its price is fairly close to that of a used Sigma - it is also heavier and the huge focus throw means that fast focus adjustments are hard to make - I'd take the Sigma over it any day.

Laur's photo blog: Sigma 105/2.8 EX DG macro
Laur's photo blog: Vivitar Series 1 105/2.5 macro

This is for the old Tamron - I expect the modern one to be even better:

Laur's photo blog: Tamron adaptall-2 SP 52B 90/2.5

[newarts]

New or old, auto or manual focus, Pentax or third party; which 100mm to 105mm macro [1:2 would be sufficient] would have the highest image quality on the k-5 [with resolution prioritized over contrast, distortion, CA, fringing, and color]?

I believe you are asking for information that does not and cannot exist because the question is too broad -even with your attempt to qualify it..

The responses that say "they are all pretty much the same" are easier to defend than identifying a particular lens as being the best regarding an ill-defined feature like image quality.

Finally, be careful what you ask for - a lens with superb resolution may take very bad photos.

I'd put resolution as the over-riding selection criterion only if my goal was a technical one like seeing the smallest possible crack opening in an integrated circuit.

What is your goal?

[civiletti]

Thanks for all the replies. I have a Tamron 90/2.5, which is a good lens, but recently bought a DA70mm and very much like my A50/2.8 for close work. So, I'd like to go to a longer macro, hence the 100-105mm range. I would use the lens at distance as well as close-up. The Voightlander 120mm certainly looks to be a fine lens, though, enough so to expand the range I'm exploring. The Leica [obviously also fine] would be problematic on a K-5, wouldn't it?

As to the priority on resolution - I've never made an image I wish had less detail, and if I did, removing detail is much easier than adding it. With digital editing, I do not see much problem with other parameters. I can tweak distortion, CA, color, etc. Bokeh does not matter much to me. I'm more interested in what is in focus.

I would like to see a direct comparison between the resolution of the A100 and DA100. If anyone has both or a link to said comparison, I would appreciate deeply.

PhotoZone tests suggest the Tokina 100mm is a bit sharper than the Sigma 105mm. Any thoughts on that comparison? Again, thanks, all.

[Laurentiu Cristofor]

Finally, be careful what you ask for - a lens with superb resolution may take very bad photos.

Please sell such junk to me, I'll make sure it gets a home.

[Laurentiu Cristofor]

PhotoZone tests suggest the Tokina 100mm is a bit sharper than the Sigma 105mm. Any thoughts on that comparison? Again, thanks, all.

Note that photozone cannot do macro comparisons - they shoot lenses at normal distance. So any difference there may not be relevant at all for macro work (if that's the main purpose of getting this lens).

Also, small sharpness differences may look important on paper but may be irrelevant in practice and may just be due to sample variation. Unless you see a big difference between the lenses, you shouldn't spend to much time comparing numbers. For example, photozone also shows the Tamron 70-300 as being sharper at 300mm than the DA55-300, which most people here will tell you is the other way around. You have to take their test results with a grain of salt.

Bottom line is that in terms of sharpness, differences between 100mm macro lenses are pretty irrelevant. Look at other features, like price, build, WR to make a decision.

[newarts]

As to the priority on resolution - I've never made an image I wish had less detail, and if I did, removing detail is much easier than adding it. With digital editing, I do not see much problem with other parameters. I can tweak distortion, CA, color, etc. Bokeh does not matter much to me. I'm more interested in what is in focus.

I apologize for beating on the resolution drum but here's an example of what I'm talking about regarding resolution:


The image on the right has much better resolution than the one on the left. Resolution is the smallest distance that can be resolved and that is usually at a quite low contrast - maybe 10%


All of the above images have the same resolution. And the low contrast ones could have their contrast improved in post processing.

PhotoZone tests suggest the Tokina 100mm is a bit sharper than the Sigma 105mm. Any thoughts on that comparison? Again, thanks, all.

Photozone's tests are pretty loose and as I recall report only mtf50 which is far from a lens' limiting resolution - it is not at all unusual for lenses to have similar mtf50's and different mtf10's.

However a lens' + sensor mtf50 is a pretty good measure of subjective image quality.

It might benefit you to read this article in Lenstip Why the Lenstip reviews differ from others? - Where could the differences stem from? - Lenstip.com

In fact the lenses you are considering (and more candidates) are reviewed by lenstip.com. Of the two you mention Tokina is on top resolution wise (mtf50 at least).

[Laurentiu Cristofor]

I apologize for beating on the resolution drum but here's an example of what I'm talking about regarding resolution:

Yes, sharpness requires resolution and microcontrast. But informally, most people talk about resolution when they mean to say sharpness. When I hear someone asking for high resolution in a lens, it is clear to me they want a sharp lens, not a lens with high resolution and low contrast.

[newarts]

Yes, sharpness requires resolution and microcontrast. But informally, most people talk about resolution when they mean to say sharpness. When I hear someone asking for high resolution in a lens, it is clear to me they want a sharp lens, not a lens with high resolution and low contrast.

I understand that but wasn't sure what this OP meant due to phrasing and extra emphasis on resolution. I expanded on it for general tutorial reasons.

OP may actually have wanted to see small detail - it just wasn't clear.

[civiletti]

Yes, sharpness requires resolution and microcontrast. But informally, most people talk about resolution when they mean to say sharpness. When I hear someone asking for high resolution in a lens, it is clear to me they want a sharp lens, not a lens with high resolution and low contrast.

Contrast and micro-contrast can be effectively increased in post-production. Detail that does not exist in the original is difficult to create.

[DanielT74]

The Leica [obviously also fine] would be problematic on a K-5, wouldn't it?

Leica is very easy to convert using Leitax special 10-whole mount and instructions:

APO-MACRO Elmarit 100/2.8

I am currently hoping to do it on the cheap, just because I already have a Leica-R to Pentax-K mount with 5 holes. If any of the Melbourne members read this and have suggestions (or tools), I'd be very interested!

[civiletti]

Leica is very easy to convert using Leitax special 10-whole mount and instructions:

APO-MACRO Elmarit 100/2.8

I am currently hoping to do it on the cheap, just because I already have a Leica-R to Pentax-K mount with 5 holes. If any of the Melbourne members read this and have suggestions (or tools), I'd be very interested!

Would this conversion preserve auto-iris operation?

[xjjohnno]

Manual iris operation is what you get with the Leica to Pentax conversion. Set aperture, focus, shoot. There may be a need to adjust the exposure.
Daniel, I'd follow their recommendation regarding the 10 hole adapter. Tools, screw drivers small enough for the job and something soft to lift out that inner plate and not scratch anything, perhaps made from an old credit card or similar plastic card.

[Laurentiu Cristofor]

I understand that but wasn't sure what this OP meant due to phrasing and extra emphasis on resolution. I expanded on it for general tutorial reasons.

Got your point now.

Contrast and micro-contrast can be effectively increased in post-production. Detail that does not exist in the original is difficult to create.

So you start from asking for a lens that has "the highest image quality on the k-5" and now you're arguing that you don't even need microcontrast because you can work it out in post-processing?

In practice, if a lens has low micro-contrast, it won't be saved by its incredible resolution. Resolution and microcontrast get affected by the same reasons - aberrations of different kinds, a bad or damaged optical design - you can't mess one aspect without impacting the other one as well.