new Macro lens

Hi,

has anyone used the new SMC P-FA 100mm F2.8 macro? Or even the smc P-FA 200mm F4.0 ED?

Are the any good? Positives vs negatives etc? How do these compare with the Tamron equivalents?

Matt, I saw in a previous posting that you like the SMC-F 100mm/f2.8, is this the new one or an older version?

Thanks

James

I think its safe to assume that any marque Macro lens, like the Pentax ones, will be superb. I would expect them to out-perform the Tamron or any other independent manufacturer, but in any event they are likely to match the cameras better as well.

The SMC Pentax-F would be an earlier autofocus lens.

James,
As John said, it's an earlier autofocus macro. There are times when chromatic aberration is high (on the *ist-D at least), but it is absolutely razor sharp and a joy to use
I have seen very good results from the Tamrom 90mm macro, but having refined my lens collection over the past couple of years I have ended up with Pentax-only

There are a few differences between the SMC-F and SMC-FA versions and the new version. The new version is more compact and a good bit lighter. It has a lens hood supplied, whereas the F & FA don't require one. Optically I cannot comment, but I suspect the quality will be equal, if not better than the older lenses. Cost-wise - you can pick up the F & FA versions for around £200 second hand which is well worth the investment

Matt

Thanks for that feedback guys.

I'm also interested to know your thoughts on getting a longer lens for macro shots.

I've had a look at the Tamron 90mm. It was nice but to achieve a serious close-up you need to get very close to the subject. I would have thought this would be a problem with insects etc.

Am I better gooing for, say, the 200mm instead?

Finally, how do the 1:1 Macro lenses go with a 2x teleconverter? Is there a noticeable difference in the magnification or is it pretty much the same at that level?

Thanks guys

James

James,

Yes, a 200mm will get you close-ups from a little further away.

And yes, you can use a teleconvertor with the macro. In fact, I have used the Pentax 1.7xAF plus extension tubes on the SMC-F 100mm macro! You actually get closer to the subject, but the magnification is quite astonishing! (Camera shake becoming an increasing problem )

It depends what you want to take. If it's insects and the like, then 180mm or 200mm macro lenses are the thing, but the price isn't nice
If you are taking stills (flowers, objects etc), then the 100mm or even 50mm are great. In all cases you have to get a little creative with the lighting too!

And as a final note - don't forget that the lenses can be used as "normal" lenses too. The 100mm is a fabulous portrait lens, absolutely razor sharp, and the f2.8 is great for very shallow DoF. Actually, it can be a little too sharp, because it shows up every single skin blemish... and not everyone appreciates that

Matt

Absolutely agree with Matt's observations.

If you were copying documents, you might want to use a 50mm macro simply because the tripod would be getting uncomfortably high with a 100mm or longer lens.

It does really depend what you want to photograph.

Depth of field will be similar with all the lenses for a given subject, because although longer lenses will have less DOF you will be using them from further away, so the magnification will be the same.

I'm probably tempting fate mentioning DOF...

at John's comment on DoF

Some people think the 200mm macro is the best lens Pentax ever produced. It is priced accordingly.

I have both the FA 100 f2.8 and the A 100 f4. Both are superb, and I have never noticed the slightest sign of CA on either.

The F lens is thought to be optically the same as the FA.

G

I found an oddball 28mm f/2.8 "macro" lens (actually, close focusing but not true Macro). It has an odd projection where the AF coupler is on the Pentax brand lenses, so I had to file it off, but it is amazingly sharp and distortion-free.

It is a "CPC Auto 28mm Macro CCT" lens, whatever that is. Just goes to show you never know what could turn up. It even has an "A" setting on the apeture ring, so I can use it in all the various metering modes.

Just be careful with non-Pentax brand lenses. Some of the Ricoh mount lenses have extra things sticking out that you'lll need to cut off or file down, or you could get stuck with the lens halfway on the camera and need to slip a raizor between the lens and body to push in the projection. In fact, I'll start a thread on that subject!

I only ever notice the CA on very strong highlights, and I'm probably asking a bit too much of the lens+camera. Otherwise, never (on the F).
Matt

It would be interesting to put the lens on a film camera with very high-res slide film, and examine the slides closely under high magnification. My bet is that you would find CA there too. It's only because it is so easy to subject digital images to critical scrutiny that we notice defects on digital that we wouldn't be aware of on film.

G

Many lenses exhibit CA on digital more than film, as the light is ever so slightly scattered by the film base. Another theory is that the small lenses over the photosites cause it, but I suspect with really sharp film you'd still see it. I don't think it's a digital sensor thing.

The only way I know of to combat this is to shoot RAW, and in Adobe Camera Raw there's a tab that will let you find and correct CA. It involves changing the size of the blue channel or the red channel relative to the other channels. It isn't rocket science, but it comes pretty close!

All you have to know is how to use the sliders to make it work.

My view is that there is not much more (if any) CA on digital than with film, but manufacturers try to persuade us that digitally-optimised lenses are better because that way they sell more lenses.

I'd be very interested to see some real-life side-by-side comparisons of the same lens in the same conditions shooting on to both film and a digital sensor.

Mind you, I think the new lenses are extremely good, but that is more because they are computer-designed than because they are digitally-optimised.

G

In on-going testing a couple of conclusions in a very complex area do seem likely - firstly that prime lenses can be significantly superior on digital and secondly that modern zooms can be much better than older manual focus ones. This is especially true of modern professional quality zooms.

Telecentric design is an interesting development, but as we only use the centre part of the field of view of 35mm format lenses much of the peripheral oblique light isn't used anyway.

I'm not sure why prime lenses should be "significantly superior" on digital. Do you mean digital is superior to film when using a prime lens, or a prime is superior to a zoom?

If the latter, I don't think many people will argue, except that what applies to digital also applies to film. If the former, why?

As for modern zooms, I agree absolutely. There is no doubt that massive computing power has transformed zoom lens design, whilst primes were already too good, in many cases, to permit of further improvement.

G