Imagine proiectată în mărime naturalăObiectivele care creează imagini proiectate APS-C sunt dezvoltate pentru aparatele de fotografiat digitale. Ele nu pot fi folosite cu aparate care au senzor de imagine mai mare ca şi formatul APS-C. Aceste obiective nu sunt compatibile cu aparatele de fotografiat pe bază de film. AF neultrasonicObiectivele cu mecanism de focalizare ultrasonică tind să fie mai silenţioase şi mai rapide decât cele cu focalizare tradiţională. No stepping motor AFLenses with stepping motor focusing mechanism are better for contrast based focusing, and are quiter and faster than traditionally focusing lenses. Fără lentilă cu dispersie joasăLentilele cu dispersie joasă ajută la reducerea aberaţiei cromatice. Fără stabilizator de imagineStabilizarea imaginii ajută la reducerea neclarităţii cauzată de tremurul mâinii, în special la distanţă focală mare sau în situaţii de iluminaţie slabă. Stabilizarea imaginii poate avea un avantaj de la 1 la 3 trepte în comparaţie cu obiectivele nestabilizate, bazate pe regula reciprocă. Montură metalicaObiectivele ieftine de obicei sunt echipate cu montură din plastic, iar cele mai scumpe, obiective profesionale, cu montură din metal. În general monturele din metal sunt mai durabile, şi sunt mai rezistente la desele schimbări de obiective. Când un aparat de fotografiat este folosit îndeosebi cu un obiectiv, materialul monturii nu este aşa de important. Fără focalizare internăPe durata focalizării lentilele cu focalizare internă nu-şi schimbă mărimea. Lentilă frontală nu se roteşteLentilă frontală fixă nu se roteşte în timpul focusării şi/sau a zoom-ului. Aceasta permite fotografului folosirea parasolarului sub formă de petală. Lentilă frontală fixă uşurează folosirea filtrului de polarizare. Cu retro filtruRetro filtrele sunt utilizate la obiective cu lentile frontale cu diametru mare, sau la obiective superangulare, astfel nu se pot folosi filtre frontale. Retro filtrele se folosesc la obiective ultra superangulare sau la teleobiective cu distanţe focale marî. |
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Monturi disponibile | Canon EF, Nikon F, Pentax K, Sony / Minolta A, Sigma |
Aplicaţii | Close-up , Peisaj, Efecte speciale |
Categorii | Ochi de peşte, Ultra superangular |
Multiplicator | 1× |
Stabilizator | nu |
Distanţa focală | 15 mm (fix) |
Contrucţia obiectivuluj | 7 elemente în 6 grupe |
Unghi de deschidere |
35mm: 180° digital: 98° |
Număr de lamele ale diafragmei | 7 |
Apertura maximă | f/2,8 |
Apertura minimă | f/22 |
Cea mai mică distanţă de focalizare marcată | 15 cm |
Mărire | 0,33× |
Mărime filtru | Datele nu sunt disponibile |
Mărime | ∅ 73.5 × 65 mm |
Greutate | 370 g |
Comentarii |
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Viteză AF | Datele nu sunt disponibile |
Sunet AF | |
Focalizare internă | nu |
Zoom intern | Datele nu sunt disponibile |
Lentilă frontală fixă | da |
Tip montură | metal |
Rezistenţă la umiditate şi praf | Datele nu sunt disponibile |
Retro filtru | da |
AF ultrasonic | nu |
Stepping motor AF | nu |
Imagine ciculară proiectată de mărime APS-C | nu |
Lentilă cu dispersie redusă | nu |
Toc obiectiv | Datele nu sunt disponibile |
Husă obiectiv | Datele nu sunt disponibile |
Parasolar | Datele nu sunt disponibile |
Adaptor trepied | Datele nu sunt disponibile |
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 iulie 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 aprilie 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 august 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...