Sigma 105mm Macro?
Posted 21/02/2011 - 10:52
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what is cheap and of excellent quality, if you don't mind manual focus and metering, is the pentax-m 100/4 macro. it doesn't go down to 1:1 macro, but 1:2, which might or might not be an issue for you. i find 1:2 to be perfectly fine, especially on aps-c.
k7, 15/4, 31/1.8, 70/2.4, 200/2.8, Metz 58
Posted 21/02/2011 - 20:01
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Park cameras are now selling the samsung 100mm macro on ebay brand new for £229-what a bargain
Posted 21/02/2011 - 23:43 - Helpful Comment
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marklj wrote:
What is meant by 1:1 and 1:2? Hear the phrase but no idea what it means.
They are expressions used to describe the size of your subject on the camera's sensor.What is meant by 1:1 and 1:2? Hear the phrase but no idea what it means.
For example; if you take a photo of an insect that is 10mm in length and the image of it takes up 10mm of the sensor (or film) then it is 1:1 - "life size" in other words.
If you take the same photo and the insect takes up 5mm of the sensor then the image is 1:2 (half life size).
If you take the same photo and the insect takes up 20mm of the sensor then the image is 2:1 (twice life size).
A true macro lens (such as the current Pentax 35mm, 50mm and 100mm versions) will focus to 1:1, however, marketing departments have decreed over the years that anything allowing you to focus closer than about 1:3 (a third of life size) be labelled as a "macro".
To get the larger-than-life magnifications (2:1 etc) you need additional focussing aids such as extension tubes or bellows. Once you get into magnifications of around 10:1 it ceases to be macro photography and becomes microscopy. If that floats your boat you'd be better off with a microscope and a camera adapter, foregoing camera lenses altogether.
One more thing, the longer the focal length of the macro lens the further away you can be from your subject and still achieve 1:1 magnification. This is why you would tend to use a 100mm macro lens for insects and nervous subject, whereas a 35mm macro lens is better suited to still life subjects such as flowers.
Hope that clears it up a bit.
Joining the Q
Posted 22/02/2011 - 01:35
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I have the great fortune to have both (running a K10D and ME-super) and they art both just about my best lenses. The 105mm is excellent on the ME! The answer is simple to me - if you want macro, get hold of the Sigma. For serious magnifications with the DA* you need extension tubes (or, what I really have my eye on, proper 2-dimensionally adjusting bellows), and, with no manual aperture ring on the Pentax lens, this causes complications.
HAVE YOU CONSIDERED getting reversing rings for a reasonable prime lens you already have (SRB-Griturn is a name that springs to mind for such cleverly-crafted things, but Kood have a huge page advert in most magazines) - you can get great results, and the budget is, clearly, much lower. Better still, get a step-ring that enables you to join one lens to the camera normally, and another in reverse - more control, more magnification. If the former is a zoom lens, more controllable, too. Or find some bellows - on EBay you see these from timeto time, often with the M42 scre mount, but adaptors M42-PK are easily available (although you'd need two, unless you got an M42 lens. These can be excellent quality - Zeiss, naturally, but also Pentax - and go for a song. The bellows give the agjustable magnification. (A bit off topic, but I was trying to be helpful financially )
Now, my question. I have wanted a ring-flash for so long, but simply can't justify £400 on Pentax's offering, or even Metz. Sunpak is not a name I am familiar with (and, for some reason, the image it gives is of cheap'n'cheerful stuff from PRC), but they are selling a GN16, with 4 LEDs for focussing/modelling, that looks perfectly good quality, and is half the Pentax. Should I take the plunge?
HAVE YOU CONSIDERED getting reversing rings for a reasonable prime lens you already have (SRB-Griturn is a name that springs to mind for such cleverly-crafted things, but Kood have a huge page advert in most magazines) - you can get great results, and the budget is, clearly, much lower. Better still, get a step-ring that enables you to join one lens to the camera normally, and another in reverse - more control, more magnification. If the former is a zoom lens, more controllable, too. Or find some bellows - on EBay you see these from timeto time, often with the M42 scre mount, but adaptors M42-PK are easily available (although you'd need two, unless you got an M42 lens. These can be excellent quality - Zeiss, naturally, but also Pentax - and go for a song. The bellows give the agjustable magnification. (A bit off topic, but I was trying to be helpful financially )
Now, my question. I have wanted a ring-flash for so long, but simply can't justify £400 on Pentax's offering, or even Metz. Sunpak is not a name I am familiar with (and, for some reason, the image it gives is of cheap'n'cheerful stuff from PRC), but they are selling a GN16, with 4 LEDs for focussing/modelling, that looks perfectly good quality, and is half the Pentax. Should I take the plunge?
If I sound condescending, it's just my style Much more equipment than know-how, so seeking to catch-up.
[K10, ME-super, lenses, flashes old and new (old - Pentax AF160 AF400FTZ; new Metz 58 AF-1, 48 AF-1, 15 AF ring), tripods, filters, connectors, converters, eye-pieces, rings, SPLENDID old Sekonic meter, bellows, 2-way rack, slide copier and lots of bits and bobs for mysterious things I don't have a clue about ...
[K10, ME-super, lenses, flashes old and new (old - Pentax AF160 AF400FTZ; new Metz 58 AF-1, 48 AF-1, 15 AF ring), tripods, filters, connectors, converters, eye-pieces, rings, SPLENDID old Sekonic meter, bellows, 2-way rack, slide copier and lots of bits and bobs for mysterious things I don't have a clue about ...
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