Images plein formatLes objectifs générant des images au format APS-C sont conçus uniquement pour les appareils numériques. Ils ne peuvent pas être utilisés sur des appareils aux capteurs plus grands que le format APS-C. Ces objectifs ne sont pas non plus adaptés aux appareils argentiques. Sans AF à ultrasonLes objectifs équipés d'un mécanisme de mise au point à ultrason tendent à être plus silencieux et plus rapides que les objectifs à mise au point traditionnelle. No stepping motor AFLenses with stepping motor focusing mechanism are better for contrast based focusing, and are quiter and faster than traditionally focusing lenses. Aucune lentille LD n'est utiliséeLes lentilles LD (faible dispersion) permettent de réduire les aberrations chromatiques. Non stabiliséLa stabilisation d'image permet de réduire le flou causé par le tremblement de la main, particulièrement lorsque la distance focale est importante ou que la luminosité est faible. Suivant la règle de réciprocité, la stabilisation d'image peut améliorer le stop d'un facteur 1 à 3 comparativement à un objectif non stabilisé. Monture métalliqueLes objectifs bon marché sont habituellement équipés d'une monture plastique, tandis que les objectifs plus coûteux, de niveau professionnel, possèdent des montures métalliques. Généralement, les montures métalliques ont une durée de vie plus importante. Il est utile d'en avoir de rechange lorsque l'on change fréquemment d'objectif. Si l'on utilise un appareil photo essentiellement avec un seul objectif, le matériau de la monture n'a pas tant d'importance. Pas de mise au point interneLe barillet des objectifs à mise au point interne ne change pas de longueur durant la mise au point. La lentille frontale est fixeLa lentille frontale fixe ne tourne pas lorsque l'on zoome et/ou que l'on réalise la mise au point. Ceci permet au photographe d'utiliser des pare-soleil en forme de pétales. Les lentilles frontales fixes rendent également beaucoup plus simple l'utilisation de filtres polarisants. Prise en charge des filtres drop-inLes filtres drop-in sont utilisés dans les objectifs pour lesquels, soit la lentille frontale est trop grande, soit le champ de vision ne permet pas l'utilisation de filtres traditionnels à l'avant de l'objectif. Généralement, les télé-objectifs lumineux et les objectifs à très grand angle prennent en charge ce type de filtre. |
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Monture(s) disponible(s) | Canon EF, Nikon F, Pentax K, Sony / Minolta A, Sigma |
Application(s) | Gros plan, Paysage, Effets spéciaux |
Catégorie(s) | Fisheye, Très grand angle à focale fixe |
Multiplicateur | 1× |
Stabilisateur | non |
Distance focale | 15 mm (à focale fixe) |
Construction optique | 7 éléments dans 6 groupes |
Angle de vue |
35 mm: 180° numérique: 98° |
Nombre de lamelles de diaphragme | 7 |
Ouverture maximale | f/2,8 |
Ouverture minimale | f/22 |
Distance minimale de mise au point | 15 cm |
Grossissement | 0,33× |
Taille de filtre | Non disponible |
Dimensions | ∅ 73.5 × 65 mm |
Poids | 370 g |
Notes |
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Vitesse AF | Non disponible |
Son AF | |
Mise au point interne | non |
Zoom interne | Non disponible |
Lentille frontale fixe | oui |
Type de monture | métal |
Étanchéité poussière/humidité | Non disponible |
Filtre drop-in | oui |
AF à ultrason | non |
Stepping motor AF | non |
Cercle image APS-C | non |
Lentille LD (faible dispersion) | non |
Étui rigide | Non disponible |
Étui souple | Non disponible |
Pare-soleil | Non disponible |
Adaptateur pour trépied | Non disponible |
6 mai 2007
Hi, I just wanted to give this lens a fair review. As the other reviewer mentioned, if you use it with an APS-C sensor digital slr, you won't see a whole lot of distortion. It's no different from the Canon brand fisheye on a camera like that. But, if you use it with film, or with a larger sensor size camera, full-frame if possible, it's really quite a beautiful, sharp, and very fish-eyed lens. On a Canon 5D it performed really well for me. I just wanted to say that on the right camera, it's really quite a lens.
5 juillet 2007
This is an excellent lens that does exactly what it's supposed to do. Optically, it's also excellent. You need to think seriously about whether you know what you're doing or anything about photography if you buy this for a Canon digital camera that's less than full frame.
You should probably stick to point and shoots until you understand lens conversion factors. If you don't understand digital crop factors and can't read basic specs, you either need to hold your money or find a dealer that you can trust to explain it to you. But the manufacturer shouldn't be accused of making a bad product because you don't understand the specs.
A previous user gives a poor rating because he either didn't read or understand the lens specifications. The rating was retain while most of the review was deleted because it simply didn't make sense. If you tried to use a 8x10 wide angle lens on a digital slr camera, you'd end up with a super telephoto because you're only using a portion of the image circle. Someone who calls this lens worthless because he bought first and thought later is blaming Sigma for his lack of attention to the laws of optics and of physics.
When you buy lenses for digital cameras, you have to take your brains out of your boots. This is a fisheye lens that's excellent on digital cameras, You get the full fisheye effect on a full frame digital camera --- OR at full 35 mm. You don't get the same effect on most DSLRS. When Panasonic Lumix claims 28mm lens width in its new line, it's not serious, but is referring to the apparent focal length when compared to 35mm film.
The lens can be used on cameras like the 20D or 30D which have a 1.6x crop factor. The news high speed top End EOS 1D Mark III will also have a crop factor of 1.3 while the 1ds and 5D are both full frame and will take full advantage of the 180 degree (on the diagonal) that this lens and other fisheyes offer. This lens is very good close to the optical quality of the Canon fisheye -- I've used both. But the game here is the intentional distortion on full frame. A standard wide-angle of this focal length does not cover 180, but something around 112 degrees -- on full frame.
If you want an equivalent of the 16-35 used a 5D on your 30d, you need to buy the 10-22. Both are rectilinear, corrected for distortion. Even the high end 1D doesn't get flll benefit of the fisheye due to crop factor. There are optical gimmicks if you want the effect, but that's not appropriate here.
The build quality of this lens is very good, not quite up to the level of the top drawer (and expensive) L lenses, but it is equal to Canon lenses for about the same price. It's difficult to use filters on this lens-- it isn't designed for them and filters would be makeshift -- and that big front element is vulnerable as with all of the real fisheyes. There are a couple of quirks that take a little getting used to in the controls for a regular Canon user.But I find it a little tricky going back to Leicas after too much time away -- and their controls vary with product. The images are high quality and a reasonably skilled photographer can produce excellent work with this lens without relyin entirely on fisheye cliches.
Users of digital cameras with crop factors should consider the shortest focal length fisheye lenses, approx 8 millimenters which also producs a 180 degree image, but in a circle. While I don't get the circular image on the 20D that I do the 5D it does give a lot of the distortion and on the diagonal approaches 180 with the rectagular image. I haven't measure it and don't have a reason.
The Sigma in a custom mount might produce interesting circular images on medium format film or digital sensors, but that would involve a careful matching of the mount to focal plane location. It is usually a waste of money to buy high end full frame lenses in shorter focal lengths for smaller digital sensors. You're paying for a lot of glass designed to cover a larger frame.
22 avril 2007
If you are trying to use this product with a dslr like I was, dont expect to see distortion. For the price go with an 8mm fish.
12 août 2007
This lens is really incredible... The quality has always been great with Sigma and this lens is as great as Sigma's reputation...
If you plan to use this lens with a Digital Camera, do not forget that there is a x1.2 coefficient (this lens is a 15mm but used on a Digital Camera, it turns into a 18 or 20mm). If you want the effect of a fisheye (180degrees), consider buying a shorter lens (8mm).
The 15mm fisheye from Sigma is a great super wide angle if used on a digital camera...