[Derridale]

Wow - good info and all rapid responses Thanks

The comparison between the Tamron 90 and the Vivitar 105 is purely one of sharpness and IQ - is one significantly better than the other?.

The reason for wanting a long focal length macro lens is for those water bugs - hence the questions re the Sigma 180, and now the Pentax 200 suggested by Buddha.

[aegisphan]

It's my Pentaxforums time of the day, while my wife and kids are watching American Idols. So I can be quite responsive .

Firstly, if you insist in getting the FA* 200 macro, there is one right now selling at ~$5500 . At that price, I would rather go with the Nikon D300 and the Nikkor 200 macro. Otherwise, the Sigma is your only choice for working distance. I still don't understand why Tamron wouldn't release the 180 in Pentax mount, that would be a killer as well. Another alternative is the Voigtlander 180/4. It's not a macro lens, but it can do 1:4. So if that's all you need, then it's the best option out of all of these.

IQ difference can only be observed at wide open, which I don't think you would use that too often. Stopping down, they're too close to each others. The Vivitar 105 does have weird highlight bokeh at macro distance (I didn't use it for any other purposes). If you really want to upgrade your 100ish macro, the Voigtlander 125 is your true answer: high IQ, great contrast, almost no CA or PF, and very smooth bokeh. Macro and infinity performances are brilliant (some macros do struggle with infinity performance).

[sholtzma]

You can search in this forum for my thread on my new Sigma 180mm. I have begun posting images as I gradually test out the lens. Hope it's helpful....

[Derridale]

Thanks to you both - that's excellent info.

Looks like the Sigma 180 is the only affordable option for the water bug macros.

And the Tammy SP90 will probably stay as my "normal" macro.

But continuing comments would still be appreciated - I'm sure I'm not the only one following this thread and comparing macro lenses.

[Eaglerapids]

Ok, I received my Pentax-A 2x-S teleconverter this evening.
Now I'm not much of a tester but I've taken a few shots of an old Roy Clark album cover.
First up the Vivitar S1 105/2.5 pulled back a bit.
wide open at 2.5


Now, the S1 at 1:1, still wide open.


Now, the S1 at 1:1 still wide open with the converter.


It is tough getting the focal plane parallel and perpendicular at f2.5! And I'm not sure if I actually did The word "love" measures exactly 5/16" from the left edge of the L to the right edge of the E. Razor thin DOF at this magnification and I'm not sure what the magnification would work out to be, maybe one of you guys might know?

So I took another at f5.6.


I'm not going to draw any conclusions here, I'd like to hear what you guys think.

Ok, this is the S1 at 1:1 cropped (the second picture) to the size of the S1 at 1:1 with converter (per aegisphan's suggestion). WB changed back to "as shot".

[aegisphan]

I can clearly see that at f/5.6, it's sharper. I wouldn't worry about the DOF since you shoot straight into a flat subject. So as long as you nail the focus, the result should be quite representative. However, I don't think the test subject would be suitable for a 1:1 test. The spacing between the blue dots is quite spacious (no pun intended).

Between the TC and non TC, I can see that the one without TC is a tad sharper. You should scale down/up one of them to compare. I guess at this distance, corners are not as important.

[Eaglerapids]

Ok, I've had a chance to play with this a bit more and maybe these will be better examples.
Viv S1 105/2,5 f16


Viv S1 105/2.5 f16 with Pentax A-2X-S
These are WB adjusted and I added +25 contrast and +15 clarity to this picture as contrast is lowered a bit using the teleconverter. There is a small loss of detail but all in all I believe I will be able to use this combo when I need more distance between the lens and subject.


I wonder how this would compare to say the Sigma 180 macro.
What I have here now is a 210 f5 or something like that.
I'm pretty happy with this setup.