was for some time that I wanted an objective like this, bright, strong, good quality optics, autofocus with a fast and too beautiful to behold.
I took the occasion of my birthday to spend part of the savings in this objective. After shooting a bit 'shop in Turin, where I found the prices a bit' high, I decided to point to the economy and take it online. I bought it from FotoColombo, ordering him to withdraw the site and by going in person, let me try it and possibly change if something was not right.
With the money saved I could buy an external hard drive, I will use as a backup ...
We come to "review": Use this goal a few weeks ago, but I remain amazed that every time the results can give. Do not forget that it is a universal objective (Sigma is a professional, but it remains a universal goal). Many think that this qualtà zoom is not much, but they are the same people who compare him to the Nikkor 70-200 VR, which costs more than three times as much.
mounting the hood sizes are still growing, and it turns into a super-professional goal! One of the things I like is the fact that turning the ring focus, and the zoom, the lens does not change, and no outside moves. This has the advantage of precluding a bit 'more of the entry of powder into the barrel, and not too unbalanced all-purpose machine (lenses are so thick they are also pretty heavy ...)
Another point for this lens is an attack on a tripod. It has a thread on the foot, allowing you to mount a monopod or tripod for quick, rotating 1 / 4 of a turn the knob locks or unlocks the goal quickly, which can rotate on its axis, allowing you to quickly change from one horizontal to a vertical shooting, and vice versa.
Another use for the tripod ring is to use it as support for using a free hand resting on the palm of your hand the entire system is stable, and the fingers remain free, allowing you to rotate the rings, while supporting the well ' objective.
The minimum focusing distance of one meter allows you to get closer to the subject, compared to the other objectives of the same type. This, coupled with the focal length of 200 mm, allows to have a macro ratio of 1:3.5.
The plastic window on the barrel allows you to always check the distance of focus, while the scale of depth of field to work in hyperfocal (actually no, or at least not in my case: the scale of depth of field is calculated for a full size sensor, so it is accurate only with the D700, D3 and D3x).
The autofocus is very fast and quiet, especially at distances greater than 2-3 meters. The maximum aperture of F2.8 AF sensor also enables a slow, such as the D40, to give unexpected results with the objectives of the kit. The precision autofocus
come back later.
The overall quality is high: it is a razor, but it is quite clear. On my copy I put a UV filter for protection, however, one of the cheapest, I have not had the opportunity to see how much sharpness remains under the "smooth", but I prefer having to apply a little 'over sharpen, which have ruined the front lens.
The sore point, as to the autofocus, the accuracy is. Given the shallow depth of field is achieved by photographing small objects, you immediately notice some problems with the front-focus. To better visualize the problem I stacked some of my favorite cds:) offset from each other by about 2mm. The autofocus is pointed at the CD medium (Dire Straits - Love Over Gold).
is known, even by these small pictures (clicking on it will enlarge) that trusting Autofocus (image below) the plan Focus is about 3mm closer than it should be. By adjusting the focus manually (picture above) everything returns to normal.
This is a bit 'a nuisance, as the manual focus with the D40 is rather difficult, notwithstanding the zoom ring is quite accurate and did not play.
This problem occurs in almost all copies of this objective, and its size is typical coupling-lens camera. It may be that the same lens, mounted on another body, does not give any problem, as it may be that the phenomenon of entities increases.
About the image quality I've done some shots for a notebook with squares: the grid drawn with thin lines offers a glimpse of clarity, as well as the vignetting and distortion.
the order we have:
200 mm - F2.8: Vignetting is apparent, but can be corrected. Closing of a stop is reduced a lot. The sharpness is good. There is a barrel distortion easily correctable.
200 mm - F8: very good sharpness, vignetting disappeared, the distortion remains.
70 mm - F2.8: here is quite soft, little distortion and no vignetting.
(In this case I think the lack of definition is due mostly to the problem of front focus: a 70mm f2.8 depth of field is a few millimeters, an error of focus can make a picture of a object perpendicular to the sensor quite blurred)
These faults (mainly the front-focus) can be seen only under particular conditions, such as shooting close subjects with aperture wide open. In normal is difficult to notice, so that some owners are not even aware.
70 mm - F8: high definition, no distortion and no vignetting.
These faults (mainly the front-focus) can be seen only under particular conditions, such as shooting close subjects with aperture wide open. In normal is difficult to notice, so that some owners are not even aware.
soon, with some pictures on the field!
