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Color and Contrast: I was expecting good color and contrast from this lens as there is very few optical surfaces in the path of entering light (its made of 5 elements in 4 groups). I made a comparison with the 70-210/4 "beercan" in this area. As many people agree, the beercan is known to have outstanding color and very good contrast. I'm comparing this little plastic thing against nearly the top-tier in terms of color and contrast.

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Manual Focusing: the focusing ring looks very friendly, but with the first touch, you realise the problem. The friction is so high that it affects manual focusing. You have to apply a small amount of force before the ring decides to turn. Then it suddenly makes a jump before you can stop pushing. This is really frustrating but there is a solution; holding the ring tighter than usual allows precise manual focusing, but you have to remember this one. Also you can move the camera for fine adjustments in focus.

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Even further, this is the longest cheap prime available. You can't get a 135mm or longer lens with a price close to this. This alone makes the Cosina 100/3.5 worthy of getting a review. The big question is, can it really deliver true macro experience, or do you always get what you pay for?

Der erste Wert gibt die Brennweite, also den Zoom in mm an. Bei diesem Objektiv kann die Brennweite zwischen 18 und 55 mm eingestellt werden.

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Es gibt für unterschiedliche Zwecke eine ganze Reihe an Objektiven. Um das Thema so simpel wie möglich zu halten, werden kurz die gängigsten Objektive angesprochen, sowie deren Einsatzgebiete genannt.

* At all aperture settings, the aperture blades doesn't make up a symmetrical shape. It's rather like an oval (but not circular) I haven't seen egg shaped highlights so far, but i guess it may happen.

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Bokeh: nothing much to say here, OOF rays are rendered without ugly scattering effects.. the bokeh looks pretty "simple". (may be this is also about the not complicated optical design) While i didn't provide comparison shots, beercan's bokeh is no where as good as this one, and still its referred as a 'bokeh' lens. Overall, excellent performance from the cosina.

Focusing is done by extension, which means the optical assembly moves forward and backward inside the lens barrel for focusing. Since this is a macro lens, the focus mechanism has a long throw and lens extends to twice of its length when focused to closest distance. Telescoping parts of the lens wobble, but not much as one would expect. The real problem about build quality will be covered in the focusing part.

Mit dem Makroobjektiv können sehr feine und kleine Details, wie beispielsweise Insekten 1:1 abgebildet werden. Auch für die Porträtfotografie oder verschiedene Tieraufnahmen kann ein Makroobjektiv interessant werden. Hier können die Brennweiten stark variieren.

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Aberrations: no distorion, no noticable vignetting, no CA, but lots of purple fringing around shiny spots... this is the only optical fault of the lens so far it seems.

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And here comes the sharpness comparison shots. all converted from RAW, no sharpening or noise reduction. At the end you'll see comparison shots from the Beercan. The test target:

Das Normalobjektiv ist wie der Name schon sagt ein Standardobjektiv, welches häufig beim Kauf einer Spiegelreflexkamera enthalten ist. Meistens betragen die Festbrennweiten um die 50 mm und eignen sich beispielsweise für die Porträtfotografie.

Note: This lens is being sold with different labels on it. For your convenience, here is a list of brands that sell the cosina 100/3.5: Pentax (discontinued), Vivitar, Phoenix, Promaster, Soligor and voightlander. Before we get into sample shots, i'll do some verbal evaluation of the lens.

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* while the maximum aperture of 100/3.5 is supposed to be F3.5, 5D registers it as F3.2. Aperture can be set to F3.2 without exposure problems. I further investigated this by using the same exposure time in M mode with F3.2 and F3.5, there were no differences in histograms. That means the lens can't actually go up to F3.2. I don't think choosing this setting would cause big problems as 3.2 and 3.5 is pretty close.

Das Weitwinkelobjektiv erfasst durch eine größere Brennweite von ca. 28 bis 35 mm ein größeres Umfeld als das Normalobjektiv. Das Weitwinkelobjektiv eignet sich perfekt, um beeindruckende Landschaften zu fotografieren.

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many people have reported the 100/3.5 to be badly built. This is only partly true. The exterior parts of the lens is made of plastic, a kind of plastic that we aren't used to see with lenses. However the lens barrel and other parts feel strong and can take some pressure.

SubjektivBedeutung

Wenn Du ein Objektiv kaufst, muss es nicht zwangsläufig der gleiche Hersteller Deiner Kamera sein. Wichtig zu erwähnen ist, dass der Anschluss der Objektive variieren kann. Hier sollte man sich vor dem Kauf über die Kompatibilität informieren. Häufig kann auch ein Adapter Abhilfe schaffen.

you were wrong, image 1 is taken with Cosina 100/3.5 macro which visibly beats the beercan in terms of color, and equals in terms of contrast. Unexpectedly big achievement indeed. I know color is something relative, but which one do you think looks more plesant? my less scientific experiences also tell colors are pretty good with the cosina.

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* provided rear cap doesn't open the aperture, i don't know if storing the lens with closed aperture for long time may cause problems.

The plastic fantastic is pretty small, just about the same size with the 18-70 kit lens. but this doesn't explain the fact that its the lightest lens i have ever held. Its almost lighter than 28/2.8 which is much smaller. But thats a good thing since the lens seems to be more than strong enough to hold itself in one piece.

Teleobjektive verfügen meistens über eine hohe Brennweite, damit aus einer größeren Entfernung sehr genaue Bilder aufgenommen werden können. Dadurch wird der Blickwinkel auf das Motiv stark verringert. Ein Teleobjektiv eignet sich z.B. gut für Sportaufnahmen und hat eine Brennweite von ca. 70-200mm.

Auto Focus: To go from infinity to closest distance (which happens to be at 1:2 magnifaction) the whole optical assembly of the lens has to move 5 centimeters, which is a pretty long way and HUGE friction caused by internal mechanics doesn't help either. Drop in the fact that AF drive system has a fast gear ratio, i think you can guess the sound of massive torque of the AF motor working against the friction to move whole optical assembly.

Das Objektiv ist sozusagen das Auge der Kamera. Die Funktion eines Objektives dient der Einstellung von Blendenöffnung und Zoom. Je nach Objektiv können verschiedene Blickwinkel eingenommen werden. Diese können sehr eng, aber nah am Motiv sein, aber auch sehr weit und weiter entfernt sein.

Je nach Situation kommen unterschiedliche Objektive zum Einsatz. Abhängig vom jeweiligen Zweck der Aufnahmen wird das eine, oder ein anderes Objektiv verwendet. Für den Anfang reicht jedoch das Normalobjektiv, damit erste Erfahrungen beim Fotografieren gesammelt werden können. Je nach Bedarf kann mit der Zeit da Equipment aufgestockt werden.

The good thing is, lens elements doesn't change their positions at all, they are simply fixed within the telescoping barrel, which means the wobbling and growling of focusing mechanism has no impact on optical quality.

Since this lens can focus down to only 1:2, the manufacturer includes a close-up filter for free. With the filter, the lens can focus down to 1:1 magnifaction, and there seems to be no change in optical quality as the filter is specifically designed ("matched") for this lens.