The answer is simple and fairly non-technical: The one that suits you best! Let me explain this statement before you label it as an example of circular logic .

I have a fairly large selection of lenses ranging from a prime of about age 40 to an up-to-date one costing more than a good DSLR body.  Among these, I have a lowly 28-70mm f/4 zoom which cost almost nothing because it came on a film SLR I bought. Now, after some months, it almost never leaves the DSLR body it is on. There were instances when I thought that I should mount one of the others for a specific date or event. This jealous piece of glass did not let the others move in! Some of the rivals were primes; I needed a zoom!  One of the rivals was a zoom but it was “heavy”. Another zoom failed to win because it was just too big and “exuberant”.

My best lens is small, light, has a constant aperture, sufficiently sharp and respectful to the colors… In short, it is versatile… I am not so foolish as to label my other lenses as crap; all I am saying is that I find myself using this one the most. It is my best lens.

Now that you know what was MY best lens, you may as well try labelling one of yours as such. This must be very easy; you do not have to shoot brick walls or inclined targets. You just have to listen to the voice coming from your, well, heart… The method is guaranteed to succeed. Apparently, the only limitation is that you will never know for sure whether another one sitting on the shelf of a camera house might become your best, if you buy it… (”The grass is greener on the other side of the fence”). Trying by shooting within the market may not be enough and you have to spend some time with the candidate to evaluate it fully. Good luck!

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En iyi objektif, sizin için en kullanışlı olanıdır.  Objektifin fiyatı, keskinliği ile ilgili okuduklarınız, o objektif ile çekilmiş fotoğraflara hayranlığınız pek önemli değildir. En iyi objektif, diğerlerinin arasından sıyrılan, fotoğraf çekmeye giderken çantanızda değil, makinenizin üstünde olandır… Pahalı da olabilir ucuz da; “prime” da olabilir “zoom” da… Ne yazık ki, bir süre kullanmadan, bir objektifin “sizin” objektifiniz olup olmadığına karar vermeniz mümkün değildir.  Belki ödünç almayı düşünebilirsiniz

Objectives for SLRs from all brands are reviewed, compared, sold and (well, yes!) used by us. The users, raters and so on range from newbies to authorative voices like professionals or world-renowned photographers.  The prices range from a few dollars for second hand ones to ten thousand dollar or more for some exotique ones (see, for example this 256kg one:http://www.dpreview.com/news/0610/06100101zeiss1700f4.asp). For a serious amateur (aspiring or not to become a pro) the price of the lens is obviously very important. Perhaps, it would be fair to say that the price/performance ratio is in fact the most decisive factor determining a buying decision. During the exercise of “thinking about buying” photographers consult friends and resources like those can be found in sites like www.photozone.de. The information is aboundant and consist not only of impressions but also of numbers of various sorts. Among these (the largest f value, resolution, flare resistance, build quality etc.) the MTF values also get some attention. We also see comments on “sharpness at the center” and “sharpness (sometimes resolution) at the corners. Many lenses are critiqued for their lack of enough sharpness at the corners. This is, in my belief, is the most useless bit information about a lens made for  photographical purposes. Corner sharpness IS very important for lenses used in the photocopiers; not in digital SLR cameras to which my comments apply.  Of course, I would prefer a lens with a better resolution&contrast at the corners to another one that lacks it WHEN all the other features (including the price) are equal. Otherwise, this is a non-issue. Most photographers compose shots with the subject situated somewhere away from the corners. This is not surprising since if you put your “subject” at a corner, you have to “fill” the frame with “something else”. It must be a rare event indeed if such a photo is called a success.

Special note for those who consider buying a full frame (24×36mm) lens for a digital SLR with a smaller sensor: The corner sharpness values affect the MTF values and scores given to those lenses (see, for example: www.photodo.com) and a poor performance at&around the corners of a 24×36mm film frame decreases those values. Please remember that your sensor will not record those areas and the provided info is either irrelevant or misleading “for you”.

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Satın alma kararını etkileyebilecek diğer pek çok özellik arasında, “bir objektifin kenarlarda pek net olmadığı” bilgisi en az önemli olanıdır. Özellikle de söz konusu objektif, filmli makinalar için üretilmişse… Çünkü, hemen hiç kimse fotoğrafındaki en önemli öğeyi “kenara” koymaz. Bu yüzden, MTF skoru gibi bilgiler veren sitelere bakarken, kenar keskinliği az olduğu için skoru düşen objektifleri kötü kabul etmemek gerekir.  Varsın, öyle olsun!