[garys]

I been looking for an FA2.8 Pentax 100 macro because the price would be less expensive then the new one. My question, Has technology gotten that good as to be able to make the new 2.8 macro so small and still have the quality of the older FA2.8? I really need to know something before a buy a macro lens. I also looked at the Sigma 105.

[kittykat46]

The IQ of the D FA 100mm f/2.8 is similar to the old FA 100mm. They did some work to improve it for Digital use, because colour fringing when used on dSLRs is a problem with the old film-era lenses, especially stopped down.

If you often use the macro wide open f/2.8, the Tamron SP 90mm f/2.8 Macro gives much better sharpness wide open. The DFA 100mm f/2.8 is sharpest at about f/12, rather soft at f/2.8

[creampuff]

garys, you're making a wrong assumption that the FA100 macro would be less expensive than the DFA100 macro. By all counts, the FA100mm is the superior lens optically and in build quality. It is however a heavier and bigger lens than the DFA100.

Imo, Pentax compromised too much optically when it decided to design the DFA100 macro to be smaller and lighter than its predecessor. It's not a bad lens per se, especially with the Quick Shift feature, but if you've tried equivalent 100mm macro lenses from Canon, Nikon and Minolta like I have, they all show superior optical performance over the DFA100 macro.

[creampuff]

The IQ of the D FA 100mm f/2.8 is similar to the old FA 100mm. They did some work to improve it for Digital use, because colour fringing when used on dSLRs is a problem with the old film-era lenses, especially stopped down.

If you often use the macro wide open f/2.8, the Tamron SP 90mm f/2.8 Macro gives much better sharpness wide open. The DFA 100mm f/2.8 is sharpest at about f/12, rather soft at f/2.8

I'd have to disagree that the image quality of the DFA 100 is similar to the FA100. The FA100 is definitely better imo.

The Tamron 90mm macro is a popular choice because it is the most affordable compared to other 3rd party makes such as the Sigma or Tokina. It is an old optical design that hasn't changed much when it came out as a MF lens or now as an AF design. Unusually for a macro, is sharper at the wider apertures rather than when stopped down. In AF mode, it tends to hunt when focusing at large magnifications and is probably better used manually.

[frank]

creampuff is correct. Actually on digital, the FA100/2.8 has less colour fringing problem than the DFA version (which is pretty bad wide open to F4 or even F5.6). The FA100 is probably slightly sharper wide open as well. Go for the FA100 macro if you don't mind the weight.

[raider]

In AF mode, it tends to hunt when focusing at large magnifications and is probably better used manually.

Since it is recommended to use the Tamron 90 in manual mode, would it be better (more economical) for us if we just buy a MF macro lens instead of the Tamron 90? Say the Vivitar 90mm, Vivitar 105mm, etc?

[creampuff]

Since it is recommended to use the Tamron 90 in manual mode, would it be better (more economical) for us if we just buy a MF macro lens instead of the Tamron 90? Say the Vivitar 90mm, Vivitar 105mm, etc?

Ah but some people find AF indispensable when not shooting macro subjects. My FA50 and DFA100 often time fail to lock focus simply due to the longer lens extension and inevitable light falloff at larger magnification. At such time AF is of limited use. But when shooting portaits or candids at longer shooting distances, AF is far faster than focusing manually. With AF, one can even shoot without bringing the eye to the viewfinder. I can't do that with a MF lens.

Aside from the Tamron, the lenses you mention are out of production but still command a good premium in terms of price. One thing I personally prefer the colour rendition of the modern lenses.

[raider]

I am interested to get a macro lens purely for macro work (not intending to use it for portraits or candids). In this case, what macro lens would you recommend apart from Tamron 90 or DFA100/2.8?

[Ben_Edict]

Since it is recommended to use the Tamron 90 in manual mode, would it be better (more economical) for us if we just buy a MF macro lens instead of the Tamron 90? Say the Vivitar 90mm, Vivitar 105mm, etc?

Manual focusing is the usual way to go in macro photography, quite independent of the lens brand or technology. I can heartily recommend the Tamron. I choose it over the old FA 100, because of its compactness and lighter weight, combined with a very high IQ.

Ben

[Lowell Goudge]

as others have noted, manual focus for controlling the image is the way to go, therefore don't rule out the pentax SMC-M 100mm F4, alonmg with an extension tube set.

the only drawback is that you don't have P-TTL flash.

[raider]

Using extension tube with the SMC-M 100/f4 would reduce very much the working distance, right?

Would this approach be suitable for taking macros of bugs/insects (live ones) such as butterflies and grasshopper?

[Lowell Goudge]

Using extension tube with the SMC-M 100/f4 would reduce very much the working distance, right?

Would this approach be suitable for taking macros of bugs/insects (live ones) such as butterflies and grasshopper?

Note that working distance is a function of focal length, and only focal length.

any lens, to get to 1:1 is working at a distance of 2x focal length.

to get this with a 100mm macro (SMC-M 100F4) needs 50mm of extension tubes because the lens itself has the first 50mm built into the focusing.

a shorter lens like some of the 50 and now 35 mm macros are having you work much closer.

Note that for any of these lenses, live macro photography is difficult because the subjects move. Butterflies especially.

[raider]

So what lens would you recommend (apart from the Tamron 90 and DFA100/f2.8) that are both economical and yet practical for butterflies macro?

I am aware of the vivitar 90mm, 100mm, judging from the feedback by many users here, but I am interested to know if other brands/models should also be considered.

Back to your ext tube with a M100 F4... One of the issues with ext tubes is loss of light. So an F4 lens needs even more light to get the same shutterspeed when using ext tubes. The longer the ext tube the more the light fall-off. In that case a faster lens of 2.8 could only help. And with bugs it is all about shutterspeed since they are moving.

Now about other lenses to consider. For AF options the two you mention are very good along with the Sigma 105.
I have the MF Vivitar 105 and I really like it. A cult classic that deserves its reputation.

If you are not in a hurry you can watch the forum market place for one of the old manual ones... That what I did, I just used my 50-200 + raynox 250 until I finally found the vivitar for sale. The raynox 250 was about 40 dollars and mounts on just about any of the your old lenses. It is a fun option till the lens you want shows up.

Or you can just get the tamron 90 with the $90 rebate. It is a great lens...

[creampuff]

raider, as I said the DFA100 and Tamron 90mm (Both 1:1) isn't bad per se and for the most part macro lenses in general are well corrected and above average optically. The other alternatives I can think off are the current Sigma 105mm f/2.8 AF macro (1:1) which is very sharp but some people don't like its bokeh. I have the older Sigma 90mm f/2.8 macro (1:2) manual focus lens which is very, very good but quite difficult to find.

Tokina's 100mm macro is very good but sadly not available in Pentax mount. There is of course the excellent Voigtlander Apo Lanthar 125mm (1:1) but now hard to find and costs much more than new. If you are on a very tight budget, the Cosina/Vivitar/Pentax FA100mm f/3.5 (1:2) plastic fantastic is another to consider. Very cheap hard plastic build but delivers great images for the price.

Practically speaking, I'd recommend that you get a lens with at least an A setting (PK-A mount) for the aperture for the very simple reason that macro photography relies a lot on aperture control to manage depth of field. Being able to shoot in aperture priority for shy and fast moving macro subjects like butterflies is a definite advantage.

If you don't need the longer working distance and don't just want to shoot insect macros, then the 50mm macros might fit the bill. The wider FOV and closer working distance makes this focal length well suited for still life, flowers, product and food photography. Again the FA 50mm f/2.8 macro is the one to go for.

I share the comments of Igilligan with regards to getting a macro lens that has a large max aperture. Light fall off is definitely an issue, especially when using extension tubes or bellows. It becomes even more of a challenge to focus manually at larger magnifications and one would likely need supplementary flash illumination to get sufficient DOF or to freeze subject movement.