Tamron A09, a focal length of a large aperture of F2.8 lens is priced at 3289 yuan
Tamron A09 as a film and digital SLR cameras, universal party lenses, but also has a large aperture of F2.8 F/2.8 wide aperture throughout the range of focal lengths have also compact and lightweight, easy to use.
We all know the charm of one of the large aperture lens. Tamron A09 28-75mm lens has a large aperture of F2.8, but also in film and digital SLR cameras, General Motors, with 14 16 lens, focus range 28-75mm standard zoom lens.
Tamron A09 lens diameter of 73mm, length 92mm, weight is about 10g, also claim to be lightweight, it is also very convenient to use.
Is it as sharp as the Nikon 28-70 – no way. As Clear and Brilliant as the Nikon 28-70 No Way. But, at 1/4 the cost, it is a good starter lens. It seemed to hold it’s 2.8 maximum aperture throughout the entire zoom range. It is built a bit cheap …
I implemented Norman Koren’s Imatest computer software to seem at out lens sharpness. Imatest is in most cases a beneficial product which permits that you proven up superior plots with the products result function, which often can be strictly the MTF with the lens multiplied from the MTF with the sensor.
Tamron AF 28-75mm f/2.8 SP XR Di LD Aspherical (IF) Lens for Konica Minolta and Sony Digital SLR Cameras
The predicament with carrying out this sort of checks and publishing the details is the reality that whereas there may be a person choice to keep the best appropriate result you may discover an infinite amount of techniques to have solutions that takes place to be wrong! complete concentrate accuracy is very, instead essential for example. protection may have some effect. selecting the sensor with the digital camera especially parallel for almost any sensor is important too. The focus on and focus on range could probably also have a really small effect.
In obtain to publish details from Imatest, I’d want getting within a situations especially where I could run identical evaluate over a lens a great number of situations and arrive up with especially identical numerical accomplishment and i am not however at that point. i am identifying exactly what i am going to really need to carry out that, so when i’ve a reliable methodology I’ll quite probably get started away in publishing numbers, but best appropriate now i am not quite there.
Note that your isn’t merely a criticism of Imatest, it really is a realization with the axiom GIGO (“garbage in, garbage out”). until you feed the products beneficial data, you aren’t able to anticipate beneficial details to arrive out!
So instead of publish figures i am going to probably latter really need to revise or retract, i am strictly heading to qualitatively describe the accomplishment with the lab tests as well as in portion IV I’ll existing some crops from genuine world images. genuine world pictures also give a a great offer of improved “feel” to the distinctions in between lenses. If a person lens “scores” a 45 and another lens “scores” a 52, that honestly does not reveal to you a complete great offer about how the pictures of genuine world themes will look.
I chose to appraise this lens while using Canon EF28-135/3.5-5.6 IS USM for two reasons. big their promoting price is equal (around $370 to the Tamron, $415 to the Canon) and second, i’ve an EF28-135 IS USM readily available for comparison. it is extremely easy to also argue that contemplating that is most definitely provides the Canon lens a two halt strengths in “hand-holdability”, the affordable lumination usefulness of these two contacts will probably be equal (for static themes anyway). Some individuals will probably want a comparability while using Canon 24-70/2.8L USM, but i actually do not personal one. it really is a $1150 lens, 3x the promoting price with the Tamron, and therefore quite probably not merely a immediate competitor. I also implemented a 50/1.8 for comparison, contemplating that we acquired a person of individuals too!
I do a great amount of tests, running these contacts via all apertures at 28mm, 50mm and 75mm, shooting many quite a few types of evaluate focus on along with that to “real world images” and evaluating pictures for sharpness, contrast, flare, distortion and chromatic aberration. be aware that all evaluate have been completed employing a Canon EOS 20D electronic SLR that has an APS-C sized sensor (ca. 22.5 x 15mm). I unsuccessful to evaluate the complete body usefulness with the lens employing movie or probably a complete body DSLR. center usefulness will probably be anticipated getting the same, but usefulness while using edges of the 36mm substantial body will probably be anticipated getting relatively even worse (lower sharpness and better chromatic aberration) than that witnessed while using edges of the 22.5mm frame.
Technical assessment of performance
At 28mm center sharpness while using Tamron lens was beneficial whatsoever apertures. Sharpness peaked near to f4 to 5.6 at which factor borders shapness was simply a little reduce than center sharpness. huge wide open borders sharpness was straight down a small on center sharpness, as could probably be expected, but stopping straight down to f4 brought it up nicely.
The Tamron was fairly far better compared to the Canon 28-135 whatsoever apertures straight down to about f11. At scaled-down apertures with each other contacts revealed comparative performance, with probably a slight positive aspects in the direction of the Tamron concerning borders sharpness. this could be very an incredible offer as anticipated owing to the actuality at apertures of f16 and scaled-down diffraction is frequently the restricting aspect on sharpness in the center while using body and can be the identical for all lenses.
At 50mm the Tamron was simply particularly a little sharper then the Canon 50/1.8 prime at identical aperture. The big difference was small as well as in genuine whole world pictures will probably be really hard to detect. at the same time contacts gave maximum usefulness from about f4 to f8. At f11 and more compact apertures the income of diffraction lowered sharpness.
Just for the hell of it, here’s a method reaction perform plot for the Tamron 28-75/2.8L and as well the Canon 50/1.8. The vertical axis are heading to be the spatial quantity (in cycles/mm while using sensor) at which the method MTF is identical to 0.5. As I cautioned above, will not structured as well a beneficial offer faith within complete amounts introduced here. The Canon 28-135 trailed in sharpness. It wasn’t bad but it was a notch down on the Canon prime and Tamron 28-75.
Again the Tamron 28-75 was somewhat sharper than the Canon 28-135 at all apertures. Wide open at f2.8 there was some softness but at f4 things were sharp and performance from f4 to f8 remained pretty constant. Edge sharpness increased as the lens was stopped down and peaked around f8.
In the final section (Part IV) of this review there are some real world shots which show comparative edge and center sharpness of these lenses.
These images represent an extreme flare test since they were taken with the full sun just in the upper left corner of the frame. They are 25% crops from the center of the image. They were all shot at f5.6 without a lens hood (though that wouldn’t make any difference anyway with the sun actually in the frame).
The images above show that it’s pretty clear here that the Tamron SP AF28-75/2.8 displays a lot less flare than the Canon 28-135 IS at 75mm and f5.6. So Tamron’s claims of lower flare in Di lenses isn’t just “adspeak”!
The above shots at 50mm still show the Tamron SP AF28-75/2.8 has lower flare than the Canon 28-135 and also lower flare than the Canon 50/1.8 prime. I’d have guessed the prime would have been better, but I would have been wrong!
At 28mm, the Tamron SP AF28-75/2.8 is still superior, though the Canon 28-135 isn’t quite so far behind this time. All in all the Tamron SP AF28-75/2.8 has very good flare resistance.
It’s pretty clear from the above figure that at 28mm the Tamron lens shows significantly less chromatic aberration than the Canon. The use of LD glass is obviously working here.
At 50mm both the Canon 50/1.8 prime and Tamron 28-75 show very low levels of chromatic aberration. The Canon 28-135 zoom still shows a trace, but it’s certainly better than it was at 28mm.
At 75mm both the Tamron 28-75 and Canon 28-135 show very low levels of chromatic aberration. I can maybe see just a touch more in the Tamron lens, but both would rate as “good”.
Distortion was very low at 75 and 50mm. At 28mm some barrel distortion could be seen as shown below:
The Tamron SP AF28-75/2.8 XR Di LD Aspherical (IF) Macro can focus down to 0.33m, which gives a maximum magnification of 1:3.9 at closest focus and 75mm. As I mentioned earlier, this is really more “close focus” then macro since I don’t think it’s actually fully corrected for close focus use in the way that true macro lenses are. Testing bears out this theory. Below is the full frame shot at maximum magnification:
The usefulness of an f2.8 close focus lens is illustrated in the next pair of images: As you can see, the background is significantly more blurred, and therefore less distracting, in the shot taken at f2.8. This difference in background blur is maximized when shooting at 75mm and at close distances.
Tamron SP AF28-75/2.8 XR Di LD Aspherical (IF) Macro Specifications
|Lens Construction (Groups/Elements)||14/16|
|Angle of View||75 -32|
|Focal Length||28mm to 75mm|
|Diaphragm Blade Number||7|
|Minimum Focus||0.33m (entire zoom range)|
|Macro Mag. Ratio||1:3.9 (at 75mm)|
|Diameter x Length||73mm x 92mm|
|Mount||Canon, Minolta-D, Nikon-D|