Putting aside the right choice of parameters and your skills of photographier On pourra toujours faire de très bonnes photos à 1/60 et 6400 ISO mais alors elles ne seront pas meilleures que sur un A7III de 24Mpixĭonc avant d’investir dans un A7RIV, vérifiez votre parc optique qui aura sans doute besoin d’une sérieuse mise à jour, pour beaucoup rester sur le A7III ou A7RIII sera un meilleur choix 1.2 The lenses / Les Optiques La plupart des objectifs ont assez de pouvoir de résolution pour la densité de pixels d’un capteur plein format de 24Mpix mais le A7RIV avec son extraordinaire densité de pixels toute littéralement la plupart des objectifs et très peu arrivent à révéler le plein potentiel de ce capteur de 61Mpixĭe plus on atteindra le niveau de détail maximum que dans des situations idéales par ex min 1/250s à mainlevée et ISO <800 On résume souvent cela à la notion de piqué de l’objectif qui atteint son maximum à des ouvertures de F5.6-F8 pour la plupart des optiques Plus le pouvoir de résolution est élevé, plus on pourra voir de détail sur l’image finale jusqu’à atteindre le nombre de Mpix du capteur Le pouvoir de résolution d’une optique est mesurée par sa capacité de différentier deux lignes ou points d’un objet. Le Sony A7RIV avec ses 61Mpix ne vous donnera pas de meilleur résultat que les 42Mpix du A7RIII ou les 24Mpix du A7III si vos optiques ne peuvent résoudre une telle densité de pixel So before buying/upgrading to an A7RIV check the lenses you have or should buy, for many people a A7IV, A7III or A7RIII could be a better optionġ.1 Obtenir la quintessence du capteur de 61Mpix You can still take great photos at 1/60sec and 6400 ISO but this won’t be better than on a 24 Mpix camera Most lens have enough resolving power for the density of a 24Mpix full frame sensor but the A7RIV with is crazy high pixel density is torturing the lenses and there are very few that can reveal the full potential of the sensorĪlso this full potential will only be achieved in ideal conditions with speed of min 1/250 handled and low ISO < 800 ISO This is summarized in the “Sharpness of the lens” with in general reach its max at Aperture around F5.6-F8 for any lens The greater the resolving power, the more details will be visible on your final image up to the number of Mpix of you sensor The resolving power of a lens is measured by its ability to differentiate two lines or points in an object. The Sony A7RIV with its 61Mpix will not give you better results than the 42Mpix of the A7RIII or the 33Mpix of the A7IV or the 24Mpix of the A7III if your lenses can not resolve such a high pixel density Technically, the Tamron is a G-type lens and thus does not feature an aperture ring.1 Introduction 1.1 Getting the most of the sensor of the A7RIV However, take this as an optimistic statement as usual. Full-time manual focusing (FTM) is supported.Īnother new feature is the optical image stabilizer - or "VC" = Vibration Compensation according to Tamron naming conventions - with a claimed efficiency of up to 4 f-stops. This is at least partially achieved by implementing a rather short focus path, which makes life a little harder in manual focusing mode. Autofocus operations are very fast at conventional distances. The Tamron lens features a virtually silent USD (Ultrasonice Drive) similar to Nikon's AF-S technology. The front lens does not rotate, so using a polarizer is no problem.Īs all macro lenses with F-mount the Tamron reports the effective aperture to the camera, which drops from f/2.8 down lower values with decreasing focus distance. A barrel-shaped lens hood is also part of the package. Just like most macro lenses, it has a focus limiter so you can select the focus range to reduce AF hunting e.g. The broad rubberized focus ring operates smoothly and without play. There are two major mechanical improvements compared to the old Tamron SP AF 90mm f/2.8 Di macro - the new lens is weather-sealed and it keeps a constant physical length throughout its focus range. Technically this is fine, of course - it just feels somewhat less reassuring than the Sigma AF 105mm f/2.8 OS macro or the Nikon AF-S 105mm f/2.8 VR. This is mostly because of the extensive use of plastics in the construction. The build quality of the Tamron lens is very good but it stays slightly short of what we have seen on the Nikon and Sigma side. so let's see how the lens performs on our FX test camera. It is a member of the "SP" or "Super Performance" lineup thus designed to deliver professional quality results. However, the new Tamron AF SP 90mm f/2.8 Di VC USD macro is supposed to change the game once more. Lately they fell somewhat behind due to more modern designs from other manufacturers. Tamron has a long history of providing affordable and high quality macro lenses for ambitious users. Review by Klaus Schroiff and Markus Stamm, published April 2015
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |