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The current digital S.L.R. cameras can mostly use with lenses for film S.L.R. cameras systems as well and this is wonderful for us to make the most use of conventional lenses in this digital age. However, sometimes lenses designed exclusive for film cameras are not compatible with digital S.L.R. cameras. Especially when old types lenses are used with digital S.L.R. cameras, flare and ghost appear remarkably compared to using with film cameras. In case of digital S.L.R. camera, since flatness image sensor is much higher than film beyond comparison, internal reflection causes flare and ghost easily.
In this case, sine it is rather hard to find flare and we need to be careful about it. Strong flare creates blurred image, so it is easy to see, but slight flare makes us unaware due to its low contrast and a bit out of focus.
However, it is fine if you enjoy this kind of disadvantage of old lenses as its advantage. If you prefer sharper image and enough contrast by using digital cameras, I recommend you to obtain new lens. 18-50mmF3.5-5.6 DC and 55-200mmF4-5.6 DC, exclusive lenses for digital cameras, are my most recommendable.
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| Camera: |
SIGMA SD10 |
| Shutter Speed: |
1/30s |
| Apature Value: |
F5.6 |
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| Camera: |
SIGMA SD10 |
| Shutter Speed: |
1/640s |
| Apature Value: |
F5.6 |
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| Click the picture to see the larger images. |
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Since this lens is especially for digital S.L.R. camera with APS-C sized image sensor, it is cannot be used with digital S.L.R. camera with full sized image sensor, or film S.L.R. cameras. Instead of that, its lightweight and compact body are the best features. Mostly, the longest focal point of wide-angle zoom for film cameras is until 35mm. Therefore, if using with digital S.L.R. cameras, the focal point range becomes narrow and this makes us difficult to use. However, the longest focal point of this lens is 50mm and we don't have any difficulty in this aspect. These features are big advantages for the exclusive lenses for digital cameras. In addition, filter size is quite large such as O77mm in case of wide-angle zoom using for both film cameras and digital cameras, but filter size of this lens is O58mm and this helps us to save the cost for filters.
Actually, once I tried this lens, I was surprised by its high-quality image. Its stable focus and high contrast make clear image even its affordable price. The high image quality appears because the necessary action for ghost and flare has been taken completely. Because of its rather small image circle compared to the lenses usable with both film and digital S.L.R. cameras, I was wondering if the corners becomes rather dark at largest aperture; however, no significant light fall-off in the corners and I do not need to worry about it.
The shortest object distance (25cm) throughout the entire zoom range make us more convenient to use and useful when I shoot flowers on a large scale because of its maximum photography magnification of 1:3.5 in focal length 50mm. Since this lens is not macro lens, we cannot take close-up pictures such as flower pistils only. However, it is possible to take even small flowers in fully image plane and I did not have any stress at the closest distance shooting. This lens is well satisfaction in its usage, affordable cost, and high quality of image.
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| Camera: |
SIGMA SD10 |
| Shutter Speed: |
1/60s |
| Apature Value: |
F5.6 |
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| Camera: |
SIGMA SD10 |
| Shutter Speed: |
1/125s |
| Apature Value: |
F5.6 |
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| Click the picture to see the larger images. |
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This lens is also designed exclusively for digital S.L.R. cameras with APS-C sized image sensor as well as 18-50mm F3.5-5.6 DC. Its lightweight and compact body doesn't make us feel as if it was a telephoto zoom lens and especially its overall length is just like a standard zoom lens, which is incredible and good for bringing for hiking or overseas trip.
Nowadays, many camera manufacturing companies launch exclusive lens for digital S.L.R. cameras, but most of them are wide-angle lenses or standard zoom lenses. Probably, 55-200mm F4-5.6 CD is the first telephoto zoom lens exclusive for digital S.L.R. cameras. The performance of digital S.L.R. cameras has been improving so much and under this circumstance, many consumers concentrate on only digital S.L.R. camera. For these people, lenses usable for both film and digital S.L.R. cameras are jut big for nothing and telephoto zoom lens exclusive for digital S.L.R cameras with compact body is more attractive.
Although the angle of field is slightly different depending on the size of image sensor in digital S.L.R. cameras, the focal at tele-end is equivalent 300mm or 340mm in 35mm film format. It is enough for most of situation.
Image results with high contrast and sharpen image are well satisfactory. Telephoto lens is mostly used at the largest aperture because of its shooting condition. In most of the telephoto lens shooting, the open aperture is used; therefore, optical performance in open aperture is important. This lens provides sharp image even with open aperture. You will benefit from this.
As you can see in the sample pictures, the blur is not bad. Generally, high sharpness lens tends to have double lines, but this lens makes natural blur in rough background. Not only sharp focus but also blur is important image factor for telephoto zoom lens.
People using lens of large diameter may anxious about the brightness F5.6 at 200mm focal length. Digital S.L.R. camera has more practical use than reversal film camera in ISO200 to 400. Under the normal shooting condition, I feel open aperture is enough practically. This convenient telephoto zoom lens can be used in various occasion such as portrait or snap shot. |
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