Posts Tagged ‘Focus’

[Sigma 10-20 EX DC HSM] open to new horizons

First we consider one thing, this light is already true only for the fact that with a little more or a little less than 500 euros, we are with a digital focal length 10mm (equivalent in size to a 135 mm 15), very good. Everything else is more or less.

Having need of a true wide angle after the transition to digital had translated my old 20mm in a 30mm, the solutions (for Nikon) were not many. Between expensive original Nikon 12-24, Sigma in the question and …… more or less empty, I chose the Sigma.

Certainly not the focal bright high (20mm 5.6 instead of 24 4) but less “demanding” from an economic standpoint, we talk about a difference of about 700. Among the ‘other colleague I had not mentioned anything good of Nikon.

The Sigma has a massive appearance, the slightly oversized barrel, the gold trim, the matte black paint with little clear points, the well made and robust a petal hood, give it a professional appearance.
The cap back I ‘ve been replaced with a cap Nikon not used because the’ original is very hard, imprecise and inconvenient to assemble and disassemble, the stopper front lacks in the fact that unlock the side, if we consider unsuitable always mounted hood, it was better to release a central (some may not be all nonsense ‘look at the design stage?).

The auto focus HSM (with engine internal) is extremely quiet and fast, very good. E ‘invece un po’ difficult manually to 10mm (mounted on a D200 with 11 focus points), in this case probably because of the depth and breadth of ‘framed area that makes small, therefore difficult to assess immediately if a fire or perfectly maybe slightly off. It takes a little ‘practice and training, or leave the autofocus that can be corrected manually.

Unfortunately there is not an end in the ring to focus manually so sometimes it happens to try to blur (or to focus on before) and nothing happens because you run the wrong direction (a matter of practice and habit).
L ‘Autofocus works as normal lightly pressing the shutter of the camera, the D200 does not work instead of the default’ auto button via the rear of ‘apparatus (AF-AL), but’ s service will ensure that it is a simple firmware update few minutes (but need assistance.) If they can do without.

Optically, we have a great goal that 10mm is not so “closed”, f 4 is acceptable to a wide angle all the more that Nikon would not have the best and I believe anyone else. Of course then the diaphragm closes inexorably while salt teleconverter to a 5.6 to 20mm. This is not a problem for many applications, it can become a little ‘in low light environments when we need a pair of diaphragms “security” for a better depth of field, so we should work at 8-11. Certain is that the focus could also mount a ‘different and more optical devices such as my old 20 2.8 or a zomm 17-55 2.8 or even a more “human and amateur” 18-70 f 3.5 ( sufficiently bright).

Attention to the sides and on the ground under their feet.
It can happen the first few times not to pay attention to the depth of field up to very peripheral zone and below. Being a wide angle spintissimo what is in focus from ‘infinity to 3 meters …… may not be in focus at 0.30!

Do not confuse this for a lack of definition.

Another precaution to use the flash (especially those built above the viewfinder the room but not only) could (certainly the one embedded) do not cover as wide focal length, and then give annoying although sometimes artistic areas’ shadow.

Sigma also provides a soft case but well made, attachable to a belt.
The Council for a good value for money. Of course a few minor defects but is perhaps more due to focal defects at large thrust faults that the ‘real object.

translated from ciao.it customer review.

[Nikon AF-S 70-300mm ED-IF VR] Wow!

From reviewer

I have a VR 70-300 today and get right on my D700 screwed. Since I knew that the image stabilizer lens that has two modes, in contrast to my 24-120 VR, and that one of them only a partial function, I thought it would be good, “Active” mode ( “active “Now is a nice word and sounds in any case better than” normal “…). I wondered then, of course, that the image stabilizer is not as great works. Like me the instructions but then taught, is “active” part of the function, while “normal” the picture is stable.

Then I made a sheet of 300mm and photographed me is almost the first heart in the pants slipped. So milky and blurred … uuuu?????h. But then I realized that at 300mm each pixel has a relatively small angle to dissolve, and that it might not be such a good idea was, through my window pane UNTRIMMED to photograph … :-)

So windows up, again photographed, top sharp!

Some tests focus on deviations were initially using Meterstab also not promising. Back Focus 5cm … oh jeh. After I then quarter hour had played around, even the AF fine adjustment of the extreme D700 had changed, but then returned to zero was fitted to the Focus suddenly exactly, and also whether the AF from infinity or from the Nahgrenze loslief. I can not say I understand, because bottom line, I’ve changed nothing. My guesses:

1) the lens was delivered by mail and had a temperature slightly above zero degrees; possible that I did so immediately after unpacking operated outside its specification have (cold motors / actuators, closer camps), maybe it was somewhere barely visible mist ?

2) perhaps had the brand new stock arriving only a little bit? Sounds strange, but who knows …

In any case, then my further tests extremely well. The lens has to test images at 300mm very easy pincushion, a little less than the 24-120 VR at 120mm. Surprisingly, I found that at the short end at 70mm NO apparent distortion occurs. Chromatic aberration, or color bleeding on the edge you can see, but only at magnifications above 100% clear, and only when a test image with white lines on black background. In “real” motives should be the color bleeding hardly notice unless you have eagle eyes. It has already been repeated by some people pointed out that only the current technology (> 100% magnification on the PC) is absolutely regular laymen allows lens to detect errors!

The lens is approximately 700g also very easy for its focal length range, which is more likely to shake badly, but for less critical inhibitions sure the lens is even more to use. I had before even considering buying the Sigma 150-500 to take, but about two pounds in one lens for my taste is already hard on the border of self-punishment, YMMV.

The image stabilizer is especially useful when a tele like this is remarkable when you consider how bad the picture for a long focal length without VR can tremble.

I wish to highlight even further the low price in relation to the outstanding performance to justify 5 stars. Who needs high precision (and also with the naked eye can see, or, in practical operation can meet), which will probably be a pro lens like the 70-200,2.8 access. For depth you need in any event no open aperture 2.8, unless you’d like ants optional. Maybe 2.8 will help a bit even when auto focus, who knows.

Now I have but a small fly in the ointment: the close focus of 1.5 m hurt something. Perhaps I would indeed low distortion at 70mm like to use for head portraits. Does not stop. But the Canon 500D Nahlinse is indeed a good buy, to a tele in a macro to convert. You need only a suitable adapter ring from 77mm to 67mm lens.

But overall I’m after my first tests, I also have taught that the greatest error image sits behind the camera with the 70-300 on my D700 themselves fully satisfied and do not feel its potential to have given away. If still horse feet occur, are published here.

Addendum: the positive imaging performance unbelassen (the experiment with Canon Nahlinse was also very good), but I find it easy unangenehn that the lens when extended to 300mm hisses luftpumpenm??ig something (which is probably more often occurs in telephoto zoom), and somehow quite hohl sounds like an empty Coladose. Is not really bad, but I think there is content but the relationship with the selling price on. Just so no one in my review of disappointment falls prey …

translated from amazon.de customer review.

[Sigma 10-20 EX DC HSM] An absolute dream to use

[Sigma 10-20 EX DC HSM] An absolute dream to use

By L. Otto (Surrey, England)

When I bought this lens, my mate said to me “this is one of those lenses that surprise you. You start using it and you wonder how you ever got by without it…” How true this is…I’ll briefly go through a few of the technical details on this lens as well as a few experience related finds.

Build quality:
This lens belongs to Sigmas ‘EX’ line of lenses, which are their flagship standard, optically and physically they are very well made and this lens is no exception. It is very compact, and quite heavy, giving it a tank-like build, you could probably drop this lens quite a few times and not have a problem. When zooming, the barrel extends by maybe 1cm, and the autofocus is really silent, manual focus isn’t really used because most things tend to be in focus at 10mm anyway.

Optical Quality:
Very good. Very sharp, especially when stopped down to f/8 or so. There is sometimes a bit too much flare when there is a direct light source to the lens, but CA is well controlled and details are very sharp. One important thing I’ll just point out is that this lens is NOT fisheye, and in fact lines are kept very straight all the way to the outer edges where they begin to curve, so this is a suitable lens for architecture and images can be post processed to look perfect. Colour rendition is brilliant too, and skies are always wonderfully deep. It does take some practise to get the exposure right because you get so much into the frame the sky/land balance can be tricky sometimes.

Extras: You get a Sigma EX pouch for the lens, which is durable and good quality, and you get a lens hood which in my opinion is absolutely useless. It’s only to protect from light at the extremest angles, which isn’t a lot of the time for me…

[Nikon 18-200mm] Shortcomings in the materials and manual focus

By or masturbation

In short, “no lens”. Normal person, I buy a book, you can shoot the most.

About a month ago, is using this lens every day at work. D200 camera. Buy a D200 before, D70 of Tamron Co., Ltd. was used as the 18-200. Tamron Co., Ltd. and is not locked, you can zoom the lens of SERI?SHI during the move. This lens is not locked, so Tamron Co., Ltd. is SERI?SHIMASEN.

I will have the exterior of the plastic lens. In particular, near the mounting portion with VR on and off switch, but I think it’s lighter, and when bumped, and I worry that the lack?MAZU. This is just a texture.

The beauty of the lens of the built-in ultrasonic motors, AF after total focus, and you may be able to tweak it manually, since the end of the focus ring, a little difficult to operate, and feel.

If the thumb and index finger with a ring at the zoom, focus ring is the ring finger or middle finger to operate in these two books are not sensitive about the thumb and index finger (as it may issue personal), the focus they’re fine-tuning, may significantly shift the focus. Focus on the movement of the manual focus ring, the “slow pace” of the two-stage switch?RE, I use the manual focus is enabled. However, “AF not only shooting at” people, these are not a problem.

The VR’s features, or want to see the natural light and cool, the situation is hard to use flash, you can clearly feel the effect, “can not go back to the lens of” I feel.

In general, the lens is recommended.

translated from amazon.co.jp customer review

The biggest consumers of energy in digital cameras

Like other portable electronic devices rely on a digital camera batteries to power their electronics and mechanics. Even if the battery technology has improved greatly in recent years are still very limited in their ability to produce energy.
Understand what elements of your digital camera uses more energy can help you understand why you run the battery quickly and keep the battery in the future. In this article, the list of those power hungry components. Other articles explain how you can optimize the use of the preservation of power.
The digital camera is made up of many components. Some of them are like chips, ranging from the camera and perform all automated wonderful. Some of them are mechanical motors that move to achieve the objectives of merger or change the zoom factor. And some of them are like optical lenses and mirror reflex.
All digital cameras eat different amounts of energy components. Some components consume very little energy, while others consume a lot. Digital cameras have intelligent electronics that optimize energy consumption, but for most cases, energy consumption depends on how the photographer uses the camera and its features.
Here is a list of three elements, which consume more energy in a typical digital camera:

Mr. Haparnas writes about technology and digital photography. This article can be published only if the resource box including the backlink is included. Ziv Haparnas is a technology expoert. Find more on photo printing and photography is on printrates.com – a place about digital cameras

Digital camera resolution base, exposure, focus and storage

ResolutionThe amount of detail a camera can capture is called the resolution, and is measured in pixels. The more pixels a camera, the more it can capture images and the larger one can be without becoming blurry or “grain”. High-end consumer cameras can capture more than 12 million pixels. Some professional cameras support over 16 million pixels (megapixels), or 20 million pixels for large format cameras. For comparison, it was felt that the quality of 35mm film is approximately 20 million pixels. FocusJust in the exhibition and the film, a digital camera is to check the amount of light reaching the sensor. The two elements that you need to do this, the openness and speed, are also present on conventional cameras.

Aperture: The size of the opening of the device. The aperture is automatic in most digital cameras, but some allow manual adjustment to give professionals and amateurs more control over the final image.

Shutter speed: The amount of time that light can pass through the opening. Unlike the film, the light sensor in a digital camera can be reset electronically, so digital cameras have a digital shutter rather than a mechanical shutter. These two aspects work together to capture the amount of light needed to make a good image. In terms of photography, they have the exposure of the sensor.

In addition to controlling the amount of light, the device is to adjust the lenses to control how light is focused on the sensor. In general, the lenses on digital cameras are very similar to conventional camera – some digital cameras can also use conventional lenses. Most of the techniques of auto focus.

The focal length, however, a significant difference between the objective of a digital camera and a 35 mm camera. The focal length is the distance between the lens and the sensor surface. Sensors from different manufacturers vary in size but are generally smaller than a piece of 35mm film. In order to project the image onto a small sensor, the focal length is reduced in the same proportion. Focal length also determines the size, or zoom, when you look into the camera. 35 mm camera, a 50 mm lens gives a matter physics. Increasing the focal length increases the magnification, and objects appear closer. The opposite occurs when the focal length decreases. A zoom is a goal that has an adjustable focal length, and digital cameras have optical zoom or digital – some have both. Some cameras also have the ability to focus macros, which means that the camera can take pictures very close to the matter.

Digital cameras are one of four types of objectives:

1) fixed focus, fixed zoom – These are the types of disposable lenses on the cheap film cameras – inexpensive and great for photos, but fairly limited.

2)-Optical Zoom with Auto Focus – Similar to the camera lens on a video, they are “large” and “TV” options and automatic focus. The camera in May or May not support manual focus. Indeed change the focal length of the lens rather than information that affects the sensor.

3)-digital zoom – With digital zoom, the camera takes pixels from the center of the image sensor and interpolation (change) to make a full-sized image. According to the resolution of the image sensor, this approach can create a blurry or grainy. You can manually do the same with the image processing software – just take a picture, cut out the center and enlarge.

4) Replaceable lens systems – These are similar to the replaceable lenses on a 35mm camera. Some digital cameras can use the lens of the camera 35 mm. Most images storage of digital cameras have an LCD screen so you can see your image now. This is one of the great advantages of a digital camera – you get immediate feedback on what you entered.

Of course, the display of images on the camera, would lose its charm if that’s all I could do. If we want to be able to transfer the image to your computer or sent directly to a printer. There are several ways to do so. Although most devices are now able to connect via serial, parallel, SCSI, USB or FireWire, but typically also use some kind of removable storage device. Digital cameras use a series of storage systems. They are reusable, digital film, and they use a card reader or caddy to transfer data to a computer. Many of the fixed or removable flash memory. Digital camera manufacturers often develop their own flash memory devices, including SmartMedia cards, CompactFlash cards and Memory Stick. Other storage devices removable disks, hard drives (external or Microdrive), and write CDs and DVDs. Whatever the type of use and storage, all lots of digital cameras need space for images. Usually store images in one of two formats – TIFF, which is not, and JPEG, which is compressed. Most use the JPEG file format for storing images, and sometimes the quality settings (such as medium or high).

To get the most out of their space, almost all digital cameras use some sort of additional data compression to make the files smaller. A compression routine uses models that are repeated. The image can be reconstructed exactly as it was recorded, reducing the file size does not exceed 50%, much less often. Another irrelevance routine called compression eliminates some of the best sense, taking into account the fact that digital cameras record more information than the human eye can easily detect.

By Brian Lee

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