Lens Factor (Zoom Ratio) Less Than 3 is preferable

Discussion in 'Nikon' started by anand_chauhan, Sep 2, 2014.

  1. Some one said me that my photography art is being killed by the lens I have. According to him for a lens of 18-140 mm, the lens factor that comes to play is 140/18=7.777 which is too bad. This factor should never be more than 3. For example Tamron 17-50 (<3) is a good lens but Nikon 18-55 mm (>3) is not a good lens whereas canon 24-70 mm is a masterpiece
    Is the information correct?
     
  2. Each lens formula and design has to be judged on its own reason for being and how well the designer and maker have reached that goal.
    Such "lens factor" stories as have been told you are nearly worthless.
    Is it easier to design short range lenses?
    Mostly, but such differences as suggested between the Tamron and the Nikkor are nothing but spurious, and have nothing to do with a mm or so on either end of either lens.
    BTW, welcome to Photo.net
     
  3. I`d say it`s something subjective.

    Generally speaking, the higher the magnifying power of the zoom, the lower performance we *should* expect; but there are good and mediocre lenses, where the good could outperform the mediocre, sometimes despite of their zooming range. Optical complexity and performance are not for free.
    And BTW, many different zoom lenses have a very similar performance in a given range, e.g. from the wide to the medium range, getting gradually lower in performance up to the longer end, despite of its range and quality level.

    But having said this, I wonder if the optical quality of the lens really "kills" your photographer`s art. For sure it may "kill" the sharpness of an image, or contrast, or whatever (compared to certain standards), but... is it really your case?

    There are people around here that make wonders with high compromised lenses like super zooms (say 18-200, that is, more than 11x). I have a pro 3x zoom as well as a 5x zoom... my favorite images doesn`t have nothing to do with any of this lenses (nor with others); in fact I think I prefer the versatility of the 5x zoom, image quality aside.

    Also, think on the images taken by the masters in the past... current technology is far better than that used decades ago; the images taken by, say, Henry Cartier Bresson, are surprisingly low in technical quality (sharpness, exposure, focus) if compared to those taken by any amateur with any current consumer camera. Would you say that Bresson`s "photography art" was killed by the gear he used? :)
     
  4. Welcome to photo.net!
    The quality of a lens is not always directly determined by this ratio.
    But... depending on what you are photographing, someone who really knows what they are doing and has learned how to use their gear to make real photographs will take a great photo with a 2000-dollar lens OR a 200-dollar lens. Some of Galen Rowell's most famous images for instance (google him if you get a moment) were shot with very very cheap lenses.
    Without knowing what you are shooting, it's impossible to say which is best for you, but you can take very good photos with the 18-140 lens if you know how.
     
  5. Anand - the previous version of the Canon 24-70 was nothing like as good as the latest one. It's certainly true that a "superzoom" like the 18-200 is very hard to design with good optical quality, but there are always examples that are both good and bad - for example, the 24-120 f/4 is pretty decent, and the 24-120 f/3.5-5.6 is by all accounts awful. "Good" and "bad" are very subjective as well; I utterly failed to get along with the 135 f/2 or 80-200 I owned.

    Don't expect a superzoom to be any good. Most, but not all, primes are decent; most small-range zooms (14-24, 16-35, 18-35DC, 24-70, 70-200, 200-400) are pretty good, but they're also wide aperture and quite expensive. Later lenses are usually better designs, optically. But the difference from any of these is likely to be less than that of technique, and certainly less important than what you've decided to shoot. I'd not be nearly as scared of an 18-140 as I would of an 18-200 - but I also would expect the 18-35 Sigma or a 70-200 to outperform it. That's the price for having a flexible lens on the camera and not missing a shot while you change lenses.
     
  6. Every lens ever is a compromise in one way or another. Zoomrange is a limiting factor in some ways to make an optimum design, but also a wide aperture causes headaches. Portability also. And so on. Not one single lens gets it all right.
    Simple hard rules as the "no more than 3" one are seldom true. It's about finding the lens that balances your requirements to the most acceptable compromise. Could be a 18-140 f/3.5-5.6, could be a 24-70 f/2.8. It really just depends.
     
  7. Prime lenses have zoom factor of 1 so they must be the best! Well generally they are better than zoom but that is not the rule.
     
  8. Forgive me for being totally irrelevant, but how are your pictures? Do you feel like the lens is ruining them?
     
  9. If the rule were true, then clearly one should prefer the 18-55 to the 18-140. Having tried both, I would be happy to swap my 18-55 for your 18-140. The rule might have a certain sense when all other things are equal, but all other things rarely are.
     
  10. For a long time I felt that in order to make superior images I needed superior, pro style lenses. I had a giant theft, replaced all my stolen lenses with superior, pro lenses. But I also backed up with some 'kit' lenses on the side, and also, a year or so ago, I decided to just shoot for a year with an 18~55 f 3.5-5.6 Nikkor V.R. zoom --- the 'kit' lens that is the 'cheap' lens option they sell with every new Nikon dx format camera to make the price the cheapest with the other focal lengths being optional (usually) at an additional price. (usually) Often this lens sells for $100 or even less refurbished or thereabouts, so one would guess that with its factor and its plastic construction it might produce 'cheap' results.
    I'm going to post one photo taken with this lens and two photos taken with the $200+ (refurb) 55~300 f 4.5~5.6 zoom which also has a factor of six and ask you if you can find any fault with the photos taken. They've all been posted on Photo.net and uniformly received high ratings.
    The first is from the 18~55 f 3.5~5.6 V.R., a man with a beard I stopped literally 'in the street' just to take his photo and never saw again.
    I can only post one photo per response, so I'll note that all photos are copyright John Crosley/Crosley Trust, all rights reserved, no reproduction or other use without express prior written permission from copyright holder.
    The first post (here) is Bearded Man, taken with 18-55 f 3.5-5.6 V.R. which by your friend's advice should not be a very good lens at all. What do you think about this photo? I just stopped this man in the street, said 'I'd like to take your photo, because your face and beard are very interesting to me,' and two minutes later, I had my photos and he left, never to be seen again.
    It's nice to post 'opinions' but better to let you make your own.
    john
    John (Crosley)
    00cnvU-550869584.jpg
     
  11. Here is the second image, taken with a 55-300 'kit' zoom, a lens with a factor of '6' at nearly 240 mm extension, hand held at a very low shutter speed. Refugees from Ukrainian Russian war. Posted ('New' folder) Does the 'factor' cause a problem with this lens? Personally at 800x blowup in Photoshop I can tell if EACH of the individuals whose nails show needs a manicure. How much sharper do you need to be?
    john
    John (Crosley)
    00cnvY-550869684.jpg
     
  12. Here is the third photo, a man behind Kyiv, Ukraine's protester barricades, the barricades that helped bring down Ukraine's last leader and precipitated the current war with Russia. This photo, (c) 2014,was taken at a relatively short extension, ISO 2,500 after sundown in summer, hand held, with V.R. on, one of a series of about six taken as a rapid-fire series. I was so far from the man he did not know his photo had been taken, but close enough to fill the frame. I never spoke to him and don't think he realized his photo had been taken, only that I was 'interested' in taking a photo but took it so fast I just walked away within two or three seconds, and so did he when he saw I was not coming to meet him.
    john
    John (Crosley)
    00cnvb-550869784.jpg
     
  13. Erratum above.
    The lens is a 55-300 mm not a 50-300 mm.
    I apologize for the error.
    john
    John (Crosley)
     
  14. Spearhead

    Spearhead Moderator

    the previous version of the Canon 24-70 was nothing like as good as the latest one.​

    What's wrong with it? I have an entire stock library of photos taken with that lens, some of which have been turned into life-size advertisements. One is the most published photo of kickboxing ever. Others have been the cover photos of magazines, including a large format tabloid. Lots of inside stories too. Maybe you can give some examples of where you didn't get good results with that lens.
     
  15. ShunCheung

    ShunCheung Administrator

    This factor should never be more than 3. For example Tamron 17-50 (<3) is a good lens but Nikon 18-55 mm (>3) is not a good lens whereas canon 24-70 mm is a masterpiece
    Is the information correct?​
    Absolutely not.
    For example, the new (introduced last year, 2013) Nikon 80-400mm/f4.5-5.6 AF-S VR is wonderful. At 400mm/f5.6, its optical quality is close to that from the very best Nikon super teles such as the 500mm/f4 and 600mm/f4. Needless to say, that is a 5X zoom, which I reviewed last year: http://www.photo.net/reviews/nikon-80-400G/
    And more pixel-level samples from other people than just me: http://www.photo.net/nikon-camera-forum/00bnh5
    However, even though that is a 5X zoom, its entire range from 80 to 400mm is telephoto. That kind of 5X zoom can be a lot better than another 5X or even less-than-5X zoom that goes from wide to tele. E.g. the current 24-120mm/f4 AF-S VR, which is not bad but at 24mm, its edge performance is not great.
    Concerning the 18-55mm DX, its main issues are construction quality and slowness. At one point I had two of them on loan from Nikon simultaneously. I tried to use it indoors and AF was hunting like crazy on those consumer DSLRs. And if you drop it, even in carpet, the elements become misaligned fairly easily. Those are issues you cannot just see from images.
     
  16. Good gear inpires. Mediocre gear challenges.

    Really nice images John - inspiring AND challenging. :)
     
  17. the previous version of the Canon 24-70 was nothing like as good as the latest one.​
    What's wrong with it? I have an entire stock library of photos taken with that lens, some of which have been turned into life-size advertisements. One is the most published photo of kickboxing ever. Others have been the cover photos of magazines, including a large format tabloid. Lots of inside stories too. Maybe you can give some examples of where you didn't get good results with that lens.​
    Hi Jeff. I'm not saying that the mk1 24-70, or any of Nikon's 28-70 variants, are bad lenses. Just that Nikon made a step forward with the 24-70 f/2.8 AF-S, and Canon made another step forward with their 24-70 f/2.8 USM II. All have served well as pro lenses and take extremely good pictures, but if we're going to call the Canon 24-70 a "masterpiece", that suggests a significant advance over the alternatives. The USM II really is very good, according to tests and the sample images I've seen. The Nikkor equivalent has some minor issues if you pixel peep, which - for the cost - is one reason I don't own it. Images shot with 35mm film have made it onto magazine covers, and I've seen plenty of soft images turned into double page spreads (often landscapes shot at f/22...) - but if we're talking about lens differences, I'm purely talking about technical distinctions at the extremes of lens performance. The previous Canon really doesn't seem to be as good as the latest Nikkor or, especially, the current Canon, especially at wider apertures. That's not the same thing as bad. Just as the mk1 70-200 f/2.8 VR isn't a "bad lens", but I wouldn't touch it with a barge pole because it has a particular weakness in the corners at 200mm, and I care about that.

    I assure you that if I didn't get good results with the older 24-70 it would be far more likely to be my fault than the lens's - but technology does move on, and "good" can become "better". DxO and photozone are less than glowing about the older 24-70 USM, for what it's worth.
     
  18. Prime v. Zoom: The eternal debate. Nikon 50-300 ED anyone?
     

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