Time for a new lens!

Discussion in 'Photography Beginners' Forum' started by kw1k, Apr 8, 2007.

  1. kw1k

    kw1k TPF Noob!

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    Hey whatsup , i've got a Sony A100 alpha love the camera:hail: i've had tons of fun with the stock lens. I'm pretty comfortable with the camera i really got the hang of it! however it's time for me to get a nice macro lens for this bad boy, any suggestions? what do you guys think of this one?

    http://www.bhphotovideo.com/bnh/controller/home?A=details&Q=&is=REG&O=productlist&sku=439155

    Could i get something better for the money? or perhaps something cheaper thats going to give me just as good of a final shot? thank you for the help

    -jack:confused:
     
  2. Don Simon

    Don Simon TPF Noob!

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    Hi there, are you sure you linked to the right lens there? That's an 18-200mm zoom, not a macro lens. A macro lens is one designed for close focusing and high magnification, neither of which that zoom will do well.
     
  3. auer1816

    auer1816 TPF Noob!

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    I've got the same 18-200mm zoom, but with the Konica Minolta label. It's a good overall lens and I probably use it 80% of the time. ZaphodB is right that it's not a macro lens, though.

    I picked up a macro for my Maxxum 7D (same lens mount as the Alpha), and I love it. It's a Sigma 105mm.

    http://www.bhphotovideo.com/bnh/con...s&Q=&sku=341920&is=USA&addedTroughType=search

    It's a great macro lens that will give you considerable standoff at 1:1, but it's also usable out to infinity since it's a true macro.
     
  4. Kingpatzer

    Kingpatzer TPF Noob!

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    Yes.

    As a general rule of thumb -- zooms are only good for about 3x the minimum focal length.

    That is, if the smallest focal length is 50mm, the longest you want to go is about 150mm. Beyond that you start getting chromatic aberrations. Physics allows for theoretically unlimited zoom lenses, but the real world makes 3x the practical limit.

    The other point is that the f-stop at the high end of that lens (6.3) is very slow. Unless you're only going to be using this lens in bright sun, you'll find that this lens is going to require a tripod and a subject that's willing to not move. Even at the small end, 3.5 is not particularly fast.

    Could you get something that will do 18-200mm that's better for the money? I have no idea. But I'd never spend that much money on a lens that does nothing particularly well. I think you'll find a lot more value in a lens that is faster and more focused on either the wide-angle side of things, the standard ranges, or the zoom ranges.
     
  5. EOS_JD

    EOS_JD TPF Noob!

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    To amend slightly, generally any zoom lens with a greater than 3x f/l will suffer more with ca and reduced image quality over the whole focal range of that lens. It's not just "beyond" 3x as noted above. The whole range will be affected and you would be better to buy a lens with no more than a 3x zoom - 17-50, 70-200, 24-70 all have around a 3x zoom and are generally considered better quality lenses than the long 18-200s - note I'm not mentioning specific lenses but the Canon/Nikon equivalents in those ranges are top quality lenses.

    To repeat (but slightly differently)

    The fstop at the "long end" (200mm) is f6.3 which is a very small aperture opening. You need a lot of light as King says. Generally only shooting during the day will give enough light for shutter speeds in excess of 1/200th that you'll need to shoot to get sharpish images from this lens. I suspect that at 200mm the lens will be slightly soft anyway but USM in photoshop should be able to sort that.

    At the wider end of the focal range (18mm) I'd say f3.5 is actually pretty fast. The fastest zooms in Canon land are f2.8 so this lens at 18mm is only 2/3rds of a stop slower. This only goes for the wide end. NMove to 20mm and you'll be moving to f4 and out to f6.3.

    With 18mm you do not need fast shutter speeds to get a sharp image so you should be able to shoot at the wide end in many situations. 1/30th should suffice for sharp images at this f/l.

    Variable aperture lenses though are difficult to shoot with and this is where these lenses fall down. You zoom slightly and suddenly your shutter speed drops below that 1/focal length because the aperture needs to change. Buy the fastest zoom you can and try and buyt a lens with a consistent aperture. Don't always go for long range lenses as most of the time you'll find it hard to shoot at the long end with reasonable shutter speeds.

    Something like a 17-50, f2.8, 24-70f2.8 and 70-200f2.8 from Sigma/Tamron are cheaper than their canon equivalents and are pretty decent lenses.

    One lens will not do all I'm afraid so buy well to start with and save spending later!
     
  6. firemedic0135

    firemedic0135 TPF Noob!

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    I recently picked a Tamron 28-105mm F/2.8 off ebay for 240.00 USD and have been very pleased with it.I read (some bad and some good)reviews for the lens after I bought it and none of the negative issues have been present in mine for sure.It focuses pretty closely, about 1.5' from the sensor so zoomed it is amost touching the subject.It isnt 1:1 but it is better than any other lens I have right now and I have started to use the lens almost exclusively for just about all my pics.
    The lens is a giant though.Heavy and wide.Has a 82mm filter ring so no filters for this thing.
     
  7. Kingpatzer

    Kingpatzer TPF Noob!

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    I meant "beyond a 3x zoom, the zoom suffers with ca," as you point out and not that "you can zoom out to 3x but then suffer with ca" I can see however how it could have been read that way, and thanks for making it clear.
     
  8. EOS_JD

    EOS_JD TPF Noob!

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    No worries King. Easy to read things differently and I know it can be hard when you are trying to provide helpful info in an easy to understand way. Some of my posts have been interpreted a couple of ways :D

    Cheers
    Jim
     
  9. kw1k

    kw1k TPF Noob!

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  10. EOS_JD

    EOS_JD TPF Noob!

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    Tamron 28-105mm F/4-5.6 Lens For SONY

    That f4.5-5.6 aperture is still pretty slow. If $120 is your budget you'll not get much better though.

    I'd say look at the 17-50 f2.8
     
  11. Don Simon

    Don Simon TPF Noob!

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    Er... ignoring for a moment the quality or speed of various zooms... that's not a macro lens either. In the original post you said you were looking for a "nice macro lens"... Just to clear things up, is it actually a general-purpose zoom you're looking for and not something that can focus close?
     
  12. xfloggingkylex

    xfloggingkylex TPF Noob!

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    as far as cheap macros, wednesday when the camera sites reopen my friend and I will be purchasing Sigma 70-300mm f/4-5.6 APG DG Macro lenses for our cameras. For 200 dollars I feel it is a great lens with a good range and nice 1:2 reproduction ratio for macro. Surprising quality at the 300mm end, not nearly as soft as some other 70-300 lenses.
     

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