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03-20-2012, 09:32 PM   #16
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QuoteOriginally posted by joshfishkins Quote
Thanks. I was more interested in the macro function though, and that's A LOT more usually, although the SIGMA has it from 200-300 (I think).
Not sure if somebody mentioned it, but the sigma is not a true macro. The definition of true macro is vague, for some people it means close-up, for some people it means a magnification of 1:1 or better (e.g. 2:1). 1:1 means that a subject of e.g. 1 cm will also be 1 cm on the sensor. and 2:1 means that the same subject is 2 centimeters on the sensor. The Sigma does, if I remember correctly 1:2.5 and your kit lens (18-55) does 1:3. So you do not gain much.

See RioRico's article for (cheap) macro options: https://www.pentaxforums.com/forums/pentax-lens-articles/152336-cheap-macro-b...lose-work.html

03-20-2012, 11:32 PM   #17
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Ah yes, macro zooms. The overwhelming majority of zoom lenses labeled 'macro' are not really macro, as 1) they don't reach 1:2 (0.5x) magnification, and 2) they lack edge-to-edge flatfield sharpness. Most are marked 'macro' because it's shorter and sexier than 'close-focus'.

The only *true* macro zooms I know of are the two(?) editions of the Schneider Betavaron enlarger zoom; mine is the last, identified as Betavaron 3,5...11/0.08 where 3,5...11 is the magnification range when used on a specific extension. For a slow fixed-focus midrange zoom, it's a beast. It's just 50-125mm f/4-5.6 (unmarked) and weighs 810g, mostly huge chunks of glass, brutally sharp throughout its range. It bears no resemblance to any 'macro-zoom' you've ever seen. And it's not labeled 'macro'.

Consumer-grade 'macro-zooms' needn't be lousy. By adding extension, they can even extend to real macro territory. They still lack the sharpness of real macro (and enlarger) lenses. But for shooting centered non-flat close subjects and not caring about image edges, they're just fine.
03-21-2012, 02:41 AM   #18
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Well, sorry I just had to....

I know that this is not a place for lens review nor this "Macro" is the best macro (yes I know there were some dirt specs and some hair on sensor and/or on rear element), but here is what my "toy" Sigma APO 70-300 f4-5.6 Macro Super was capable of (on pentax K10D).

Exif: f14 1/320s 300mm and I beleive that it was close to its macro limit of 1:2:


03-22-2012, 03:46 PM   #19
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Yes, it is possible to get quasi-macro shots like that with a basic 70-300 zoom. But paired with a Raynox 150, the 50-200 is capable of far better results. Over twice as much magnification, and better image quality to boot.

03-23-2012, 05:18 AM   #20
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A coincidence. Here's a very similar shot with Quantaray 28-90 Macro.

Name:  Flower -Macro-.jpg
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Size:  331.0 KB
03-23-2012, 06:31 AM   #21
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it is a shame the shots from hman and stansilav cant be compared due to the shot from stansilav being focused onlyu at the lower left of the frame.hman really nailed the focus
03-23-2012, 06:57 AM   #22
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Well here is (hopefully) somewhatt better focused photo. Both photos posted here (as all my other photos) are SOOC unless I explicitly mention otherwise.


03-23-2012, 07:54 AM   #23
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QuoteOriginally posted by stanislav Quote
Well here is (hopefully) somewhatt better focused photo. Both photos posted here (as all my other photos) are SOOC unless I explicitly mention otherwise.
great for comparison between lenses. interesting

03-23-2012, 08:29 AM   #24
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I don't always nail the focus, but when I do and it's acknowledged, I drink Dos Equis! Thanks!
03-23-2012, 08:47 AM   #25
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QuoteOriginally posted by hman Quote
I don't always nail the focus, but when I do and it's acknowledged, I drink Dos Equis! Thanks!
"I do take photographs. And when I do,... I use Pentax. Keep shooting my friends."

Sorry couldn't resist:-)
03-23-2012, 10:11 AM   #26
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Excellent!!
03-23-2012, 04:38 PM   #27
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This is an interesting discussion and concur with others that adding glass to the front is more successful than adding to the back.

My hibiscus example:



I added my Sony VCL-HG0758 to the ST 85 1.9 which had a 18mm macro ring attached to the back to give me macro focusing range. Only two lenses in my collection have 58mm front thread and the 85mm being most logical choice for this thread.

The image taken at 1/80 sec and about f2.8 to try and get a bit of dof -still very thin though with focus at front edge of stamen.
(Disclaimer/self-serving plug - this Sony optic and its tele twin are for sale in market place)

Last edited by Arjay Bee; 03-23-2012 at 05:05 PM.
03-23-2012, 04:56 PM   #28
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Now for comparison here is the same flower and same angle of view taken under same conditions - both Super Takumars (early lens coatings), camera hand held, and over cast sky with no wind on same card but using the Macro Takumar 50 preset - note the colour cast difference which can be fixed and the huge depth of field difference which can't be fixed in post processing:



Both images are un processed - just resized for the thread.

For portability and ease of use I like the dedicated macro (which also allowed me to get in really close amongst the stamen but only at these greater magnifications did dof start to thin down). For return for dollar dedicated lenses will always beat the clip on solutions whether looking at macro end or tele end and going for old glass will keep divorce threats down.
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