nice photos taken with Smooth Trans Focus lens
- Thread starter ninelives
- Start date
- Status
ninelives
Senior Member
I found some infos about this STF lens :
In the past, photographers would often put up with needless frustration using other defocusing methods. And, other processes would often produce soft-focus photos that lacked a realistic look. The new Minolta Smooth Trans Focus lens has eliminated the factors that compromise the quality of defocused images. Instead, with the introduction of this innovative new lens, Minolta engineers have provided photographers with a powerful tool to create smooth transitions from focused to defocused areas.
Lens construction includes an apodization filter to realize a natural shift from focused to defocused areas. As a result, the original outline of the subject remains clear, the image is provided with depth, and the subject is visually outstanding. The lens is also designed to minimize unwanted lens aberrations that deteriorate the quality of defocused image areas.
The new Minolta STF 135mm f/2.8 (T4.5) lens contains a 10-blade* circular aperture which also contributes to a smoother rendition of defocused highlights; such as blurred points of sunlight coming through a forest.
In both sharply focused and defocused areas, the Minolta STF 135mm f/2.8 (T4.5) lens offers outstanding imaging performance. The lens minimizes close-focus aberrations using a "floating" focusing system, which offers excellent imaging performance from corner to corner without vignetting.
Considering that a larger aperture is more effective for a defocused image area, Minolta incorporated into the STF 135mm f/2.8 (T4.5) lens, an aperture ring which features manual, stepless adjustment in the T/4.5-T/6.7** range to facilitate fine aperture tuning. A wide focusing ring also offers superior manual focusing control. Finally, the lens has a handsome, stylish appearance that speaks of its quality.
By introducing the new Smooth Trans Focus 135mm f/2.8 (T4.5) lens, Minolta is underscoring its commitment to photography and to serious photographers by developing and offering innovative and attractive, high quality lenses that add value to the Minolta Maxxum camera system.
* 10-blade aperture for manual aperture control, 9-blade aperture for automatic aperture control.
** The effective aperture of a lens taking into account the light lost by absorption or reflection in the lens as well as the f-number.
In the STF 135mm f/2.8 (T4.5), effective aperture is expressed by a T-number since the amount of light is decreased when it is transmitted through the apodization filter.
The incorporation of the apodization filter does not result in a darkening of the image toward the edges, as the absorption of light is evenly distributed throughout the entire image.
taken from : http://www.carsand.com/Min135STF_Press.htm . you can also read more from official website . http://www.minoltaeurope.com/pe/lensesaccessories/135stf.html
and according to Paul in yahoo group, STF lens is for beautiful boken. soft forcus is for soft forcus.
Magnus Wedberg
New Member
Hi all! I am the author of the review, and yes, I should update it with a few things, but I'm a lazy guy.
I just want to emphasize that the STF lens is not a soft focus lens. The main, focused subject is perfectly sharp, while the out-of-focus areas get a "creamy" rendition between sharp and unsharp. The rendition of out-of-focus areas is popularly called "bokeh", and the 135 STF is specifically made to maximize bokeh quality.
Have a look at J Greelys STF comparison between the 135 STF and the "normal" (now discontinued) Minolta 135/2.8:
http://www.munitions.com/jgreely/stf135/
Of specific interest is this comparison,
http://www.munitions.com/jgreely/stf135/s/stf-3.html
(reference picture with "wrong" part in focus)
http://www.munitions.com/jgreely/stf135/s/stf-3a.html
(normal lens) versus
http://www.munitions.com/jgreely/stf135/s/stf-3b.html
(STF lens). Notice that the main subject stays sharp, while the quality of the out-of-focus areas have improved considerably. The old non-STF lens exhibits many characteristics of so-so bokeh; highlights are obviously affected by the non-round shape of the aperture, thin lines are "doubled" (look at the yellow poles in front of the pick-up truck) and out-of-focus objects are still easily distinguishable as their main shapes are fairly unaltered.
A soft focus lens, on the other hand, produces a dreamy effect over the whole frame, and is actually easiest to note on the main subject. The subject stays pretty sharp, but seems to be surrounded by a halo of sorts (or overlayed by an unsharp image, if that fits better). It's hard to describe the effect, but it's easily seen -- search Google for examples. http://www.pixilver.com/tutor_softfocus.html contains a good description of how to acheive this effect with software means on your computer.
All major manufacturers except Nikon (OTOH, they make soft focus filters) make soft focus lenses (I believe Pentax has a 28 soft focus, which is somewhat odd) but only two have current products trying to maximize bokeh; The Nikon 135/2 DC (Defocusing Control) and Minolta, with their 135 STF lens and the 85/1.4 Limited Edition (which does not use STF technology regardless of my faulty assumption on the review page). And, of course, Leica.
Soft focus effects can be used without owning a soft focus lens, while good bokeh cannot be simulated by any other means.
Regards // Magnus
I just want to emphasize that the STF lens is not a soft focus lens. The main, focused subject is perfectly sharp, while the out-of-focus areas get a "creamy" rendition between sharp and unsharp. The rendition of out-of-focus areas is popularly called "bokeh", and the 135 STF is specifically made to maximize bokeh quality.
Have a look at J Greelys STF comparison between the 135 STF and the "normal" (now discontinued) Minolta 135/2.8:
http://www.munitions.com/jgreely/stf135/
Of specific interest is this comparison,
http://www.munitions.com/jgreely/stf135/s/stf-3.html
(reference picture with "wrong" part in focus)
http://www.munitions.com/jgreely/stf135/s/stf-3a.html
(normal lens) versus
http://www.munitions.com/jgreely/stf135/s/stf-3b.html
(STF lens). Notice that the main subject stays sharp, while the quality of the out-of-focus areas have improved considerably. The old non-STF lens exhibits many characteristics of so-so bokeh; highlights are obviously affected by the non-round shape of the aperture, thin lines are "doubled" (look at the yellow poles in front of the pick-up truck) and out-of-focus objects are still easily distinguishable as their main shapes are fairly unaltered.
A soft focus lens, on the other hand, produces a dreamy effect over the whole frame, and is actually easiest to note on the main subject. The subject stays pretty sharp, but seems to be surrounded by a halo of sorts (or overlayed by an unsharp image, if that fits better). It's hard to describe the effect, but it's easily seen -- search Google for examples. http://www.pixilver.com/tutor_softfocus.html contains a good description of how to acheive this effect with software means on your computer.
All major manufacturers except Nikon (OTOH, they make soft focus filters) make soft focus lenses (I believe Pentax has a 28 soft focus, which is somewhat odd) but only two have current products trying to maximize bokeh; The Nikon 135/2 DC (Defocusing Control) and Minolta, with their 135 STF lens and the 85/1.4 Limited Edition (which does not use STF technology regardless of my faulty assumption on the review page). And, of course, Leica.
Soft focus effects can be used without owning a soft focus lens, while good bokeh cannot be simulated by any other means.
Regards // Magnus
Magnus Wedberg
New Member
I missed this post. I have also missed that Nikon have two DC lenses; they are not, however, soft focus lenses.
- Status
