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Although the digital SLR was very expensive item for the professional photographers and certain enthusiast in the past, some reasonable priced digital SLR are in the market now. Therefore, many users, not only the conventional film SLR users, but also P&S digital camera users start using digital SLR. Most of such digital SLR has the smaller size image sensors than film. Due to the difficulty in making such large image sensor, the manufacturing cost for the film size image sensor is extremely high and such image sensor may potentially have the image quality problem in the corner with some specific lenses. That is why most of the digital SLR uses the APS size image sensor.
However, the digital SLR with APS size image sensor also has the headache. Even if you use the same focal length lenses, APS size digital SLR provides the narrower angle images compared with 35mm film cameras. Wide angle lens works as standard lens, standard lens works as medium telephoto lens and medium telephoto lens works as telephoto lens. In this case, the headache is in the choice of the wide angle lens. The first digital SLR that I bought was Nikon D1, however, I did not have any Nikon lenses then. Therefore, the only choice for the lens that covers 28mm equivalent angle of view was bulky and expensive 17-35mm class lenses. After that, the digital SLR body price has been gradually decreased, however, there was no reasonable price lens that covers 28mm equivalent angle in the market for a long time and we had to choose such an expensive 17-35mm class lenses.
However, such situation was changed dramatically when Canon introduced 18-55mm dedicated for Canon digital rebel. By adding only 20,000yen to the body price, you can get the standard lens that covers 28mm equivalent angle now. This tide has been strongly accelerated by the introduction of SIGMA 18-50mm F3.5-5.6 DC and 55-200mm F4-5.6 DC. Both lenses are designed dedicated for digital SLR with APS size image sensor. By making the image circle smaller, these lenses implement the compact size, light weight and reasonable price. In addition to that, the optical performance is superb because it'fs designed only for the digital cameras. Several factors specific for the digital imaging are well considered. However, if you also use 35mm film SLR, you have to be careful. Since the image circle is small, you would see the vignetting in the corner. |
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| Camera: |
SIGMA SD10 |
| Shutter Speed: |
1/200s |
| Apature Value: |
F8 |
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| Camera: |
SIGMA SD10 |
| Shutter Speed: |
1/320s |
| Apature Value: |
F8 |
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This lens covers 28-75mm equivalent when used with the digital SLR of APS image sensor. Also the closest distance is 25cm. Since the lens is very compact, the flash light of the built-in flash is not blocked.
The hood is included in the box. It'fs also designed for the digital SLR, the light shielding is very good. Some people say that Sigma is not good when it'fs against the light and may have the ghost in the image. However, this lens proves the superb performance in such situation. I tried it on purpose, but, even under such situation, the ghost was minimum. Honestly speaking, I have never purchased such "cheap lenses", however, I was very impressed by the performance beyond my expectations. The chromatic aberration at the open aperture is small and if you step down the aperture up to F6.7-8, the image quality is virtually no problem. If you take pictures at the closest distance, depending on the digital SLR you use, you might see some light fall off in the corner, but still it'fs not bad. I wish the focus ring and filter ring would not rotate in AF mode, but it'fs acceptable since it'fs standard specification for this class lenses. If you think about the price, you should not be able to complain about it.
I own some camera manufacturer's high speed wide angle lenses. If I use them at the open aperture, the image is not so sharp and I see some chromatic aberration. Therefore, I mostly use such lenses at F4.5 or smaller and do not believe that the lens does not have to be F2.8. Also, in case of film camera, I used ISO100 reversal film. Therefore, I need such high speed lenses. However, in case of digital SLR, since the image quality at ISO400 is good enough for the daily use, the compact and light weighted lenses are quite helpful. Under such context, although SIGMA 18-50mm F3.5-5.6 DC is not high speed lens, the image is very sharp and light weight is good for the outdoor photography. Since the price is very reasonable, you can enhance your lens line up especially for the wide angle just by adding this lens in your library. If you need the wider focal length, you should try SIGMA 12-24mm F4-5.6 EX DG ASPHERICAL HSM. |
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| Camera: |
SIGMA SD10 |
| Shutter Speed: |
1/320s |
| Apature Value: |
F5.0 |
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| Camera: |
SIGMA SD10 |
| Shutter Speed: |
1/60s |
| Apature Value: |
F8 |
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This lens provides the 80-300mm equivalent focal length when used with the digital SLR of APS size image sensor. If you have a enough budget, 28-300mm F3.5-6.3 Macro would be the good choice, too because it covers the wider focal length from the wide to telephoto. Also, it can also be usable with 35mm film SLR. However, if your budget is limited, 55-200mm F4-5.6 would be nice choice. You can buy 2 lenses with the budget of single 28-300mm. For those who has 70-200mm F2.8 class telephoto lens, but would not like to use it for daily use because of the heavy weight, I can recommend this lens. This is the ideal telephoto lens for the casual use.
Since this is not high speed lens (F4-5.6), if you want to get the nice out focused back ground especially in portrait photography, you need to get closer to the subject. However, compared with the P&S digital camera which uses the far smaller imager sensor, you can be creative with the wider range of photo work capabilities. The aperture shape is nicely organized and it creates the beautiful out focus image in the back ground. I shoot Tulip flower and verified such beautiful out focus back ground.
If you intentionally take pictures against the sun, the contrast is slightly decreased with the flare, however, the dedicated hood prevents the significant ghost and flare.
Same as 18-50mm, I'm satisfied with the image quality, however, I do not like the focus ring rotates in AF mode. This limits you where to hold the lens in AF mode. Because I think this type of lens is used in AF mode in most cases, I think the focus ring should be much narrower. However, I do not have any other complaints on this lens. When I consider the price of this lens, the optical performance of this lens is superb.
Other sample photographs
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