[squish1509]

Hi
Just wondering if anyone has any advice on the best macro lens.
I have just received my first dslr camera (Pentax K-X) for christmass and wanted to buy a macro lens.
The two main lenses i have seen is the sigma 105mm and the tamron 90mm and was wondering if anyone has had experience with these lenses or any advice on what to get.
Thanks

[eccs19]

I just recently got the Sigma 105 mm, and so far so good. It's nice and sharp. Can't say anything about the Tamron though. The 105mm will give you a little more working distance, but probably hardly noticeable.

[SpecialK]

There is no "best". All the top-rated macro lenses are good performers. The Tamron seems reasonably priced for an AF dedicated macro lens.

You should visit the macro thread and see what results people can get with cheap alternatives which includes extension tubes and reversing adaptors.

[squish1509]

Hi thanks for the reply the one thing i have never really understood was the focal length to get really close up images do you have to be right next to the object or does the focal length act as a zoom.
Thanks

[Ira]

Hi thanks for the reply the one thing i have never really understood was the focal length to get really close up images do you have to be right next to the object or does the focal length act as a zoom.
Thanks

Well, of course, a 90 or 105 macro will allow you to stay farther away from a butterfly than a 50--where you would scare him (or her) getting to close. (Do butterflies get scared, or are they just anti-social?)

Another advantage to a 90 or 105t over the 50 is for studio tabletop work, where with the 50, you would have to get so close with your camera and tripod that they would get in the way of any lighting equipment. (Casting shadows, bumping into it, etc.)

That being said, I can definitely see the advantages to a 50 in the field. When you're looking for teensy weensy things to shoot, you're usually looking for them real close up, and with the 90 or 105, you would have to step BACK. Some people just prefer working closer to the subject, so the 50 wins for them.

I had the Tamron for use with my past job, and really liked it. I didn't, however, like the clutch mechanism to toggle between manual focus and AF. Although it may be sturdy and reliable, it just doesn't feel like it.

[newarts]

...the one thing i have never really understood was the focal length to get really close up images do you have to be right next to the object or does the focal length act as a zoom.
Thanks

For a particular size image in the viewfinder, the longer the focal length, the greater the distance to the subject. Always.

This works for both close-up (macro) and distant subjects.

In fact, the distance from the lens to the subject - called the "working distance" is directly proportional to the focal length; ie, if you double the focal length, you also double the distance to the subject.

The equation is: working.distance = focal.length(1+subject.width/image.width)

You asked:
" does the focal length act as a zoom." - yes in the sense that the longer the focal length, the longer the distance* .

Dave

*but the distance for a macro image is never "very far". For a 1:1 magnification (image size = subject size) the distance from the subject to the image is always four times the focal length.

[jolepp]

Both the Tamron and Sigma are apparently very fine pieces optically and the difference in FL is not radical so maybe you should look at extra features (focus clutch, limiter), build quality and other 'secondary' factors. There is also the Pentax 100mm as DFA and WR versions, where the latter would offer a unique advantage of its own. Yet another option might be the 70mm Sigma if you feel a shorter focal lenght would be the thing to have (for the lens to double as a portrait one, maybe).

[pacerr]

I'd like to repeat a point I recently made regarding choice of lens focal length:

To my mind, the missing piece of the FL...

Consider the angular perspective and the relative DOF associated with a given FL as well as its apparent crop factor in visualizing the composition allowed (or constrained) by the FL.

A crude explanation is to visualize the difference in POV between a close-up flood lamp compared to a more distant spot light. How, and how much of, the background will be seen beyond the subject and what effect will background separation have on bokeh?

It helps to visualize the extremes in differentiating your choices. Many of the same considerations apply as when choosing a portrait lens.

In a more mechanical sense, consider the working distance relative to light sources, shadows, tripod, etc. How much elbow room do you need?

H2

[nanadoo]

love, love, love the tamron 90.

[squish1509]

Hi Thanks for all the replies one last question is what do you think is a good price for each of these lenses (used).
Thanks

[hcc]

Both the Sigma 105 mm and Tamron 90mm are great lenses. Both were awarded "a Highly recommended" award by www.photozone.de, and that is rare.

I was looking for a macro lens (~100mm) one year ago and I considered both. I chose the Tamron because:

- the Tamron is lighter and smaller than the Sigma and I prefer a lighter lens, and

- I got a good deal (at the time) for the Tamron at A$510.

A new lens is currently priced at US$409 at Adorama that is an excellent deal. In addition, if you use the link provided by Adam [https://www.pentaxforums.com/forums/pentax-beginners-corner-q/128050-where-bu...-upgrade.html], you will support the forum.

As for an used lens, I do not know the market in Oz.

Hope that the comment will help.

[Spodeworld]

I have the Tamron 90mm..and it is really sharp.

[raider]

my wife has the sigma 105 macro and the sigma EN140 ring flash. The combo work very well and the lens is great....but a little slow like all other macro lens...

if the sigma 105 macro HSM is released for the pentax mount, that will be interesting.

[chickenandavocado]

if you have the chance to play with both, i guess it comes down to the "feel" of the lens and cost

optically they are both outstanding, i don't think i would be able to tell the difference in IQ between both

personally i got a good deal on the tamron for A$400 ish brand new around a yr ago so i went with whatever was cheaper at the time (build quality of the tamron 90 is still solid)

[Frogfish]

Both the Tamron and Sigma are apparently very fine pieces optically and the difference in FL is not radical so maybe you should look at extra features (focus clutch, limiter), build quality and other 'secondary' factors. There is also the Pentax 100mm as DFA and WR versions, where the latter would offer a unique advantage of its own. Yet another option might be the 70mm Sigma if you feel a shorter focal lenght would be the thing to have (for the lens to double as a portrait one, maybe).

I think this post ^^^ sums it up perfectly.

I have the Tamron 90 but I'm sure would be equally happy with the Sigma 105 / Pentax 100 WR. The 90 is also a very good portrait lens - all three have gorgeous bokehs. For insect macros I wouldn't consider less than 90mm though.