What is the magnification?

Discussion in 'Photography Beginners' Forum' started by mostlycloudy, Jan 13, 2008.

  1. mostlycloudy

    mostlycloudy TPF Noob!

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    I am looking to purchase my first SLR digital camera but I am very confused.

    I currently own a Fuji S5500 which has a built-in lens that has a 10x optical zoom.

    I understand that with an SLR camera the type of lens you add determines the type of photographs you can take. How do I calculate what magnification a certain lens would take?

    I would like to have at least 10x zoom with my new camera set-up.

    For instance what zoom does a Canon EOS 400D with an 18-55mm (standard) lens give? How about a Nikon D40X with 18-55mm lens?

    I don't want suggestions on what camera to buy just how to determine what the magnification would be with a certain lens. I hope this all makes sense!
     
  2. Mav

    Mav TPF Noob!

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    The magnification is simply the optical zoom ratio. Both the 18-55 kit lenses from Nikon and Canon are 3x optical zoom. (55/18 = 3). A 50-200mm lens would also be "3x".

    Personally I'm not a big fan of the "super zoom" type lenses because they have to make a lot of tradeoffs in image quality to get you the huge optical range as opposed to lenses with lower zoom ratios. What you get is convenience and not having to switch lenses, but at some cost in image quality. If that's what you really want though, Nikon's 18-200VR lens is excellent for what it is. I think Tamron and Sigma both make lenses like that as well.
     
  3. mostlycloudy

    mostlycloudy TPF Noob!

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    Thank-you for the very simple explanation. It is much appreciated and I think understood! :hail:

    I do want to be able to zoom in on a scene if necessary as this is what I am used to with my previous point-and-click cameras. What would you suggest to someone who wants to do this if "super zooms" and not the way to go? Am I misunderstanding how you zoom in on an SLR camera?
     
  4. Sideburns

    Sideburns TPF Noob!

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    Actually, I think you're misunderstanding what exactly the zoom thing means period.

    blahX zoom just means how far the farthest focal length is compared the the closest.

    So you could have a 10-100 or a 1000-10,000, but they'd both be "10x zoom". However, you could pick up martians on the moon with a 10,000mm lens....lol.

    the blahX of the lens doesn't determine the final result or how big the image can get at all. It's just a focal length comparison.

    an 18-55mm lens is actually a decent range...
     
  5. Mav

    Mav TPF Noob!

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    Don't listen to me because I only speak for my own needs and shooting style, and yours could be totally different. :wink:

    The reason I don't care for them is because when I shoot I tend to have a particular style of photo in mind or am shooting something at a particular location all of which will demand a known focal length range. It's no big deal to hook up a $150 55-200mm lens that will perform better than a much more expensive 18-200 super zoom will in that 55-200mm range. Ditto with the cheap $100 18-55 lens, which performs better from 18-55 than their 18-200VR super zoom. Plus I have two bodies, both a D40 and a D80. It's easy enough to have one range on one body, and another on the other. So I wouldn't have to constantly switch lenses anyways.

    If I had a more active lifestyle and was into hiking, biking, climbing, camping, etc, and wanted maximum versatility and minimum size and weight, I definitely wouldn't hesitate to go buy something like a Nikon 18-200VR super-zoom lens in about 2 seconds.

    So it depends on what you're style is, what you shoot, and there's really no right or wrong answer.
     
  6. Sideburns

    Sideburns TPF Noob!

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    actually, I'd beg to differ Mav. The 18-200 Nikon VR lens, is a very highly respected piece of glass, and is really something considering how wide the zoom is.

    If there was a Canon equivalent, I'd have it in a second.
     
  7. mostlycloudy

    mostlycloudy TPF Noob!

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    Perhaps I should re-phrase my question to be how would I replicate the zoom capabilities of a camera such as the Fuji S5500 (see http://tinyurl.com/6wjev for details, I think it is a 37-370mm equivalent lens) with a digital SLR?

    I know the SLR camera will be superior in most aspects (if not all!) but what lenses should I buy to enable me to replicate that type of camera? I don't need to know exact specifics (ie make and model), the xx-yy lens would be good enough for me to begin understanding this subject.

    What I don't understand is why a 10-100 would be better/worse than a 100-10000 lens. Any pointers to a good beginners website would be appreciated!

    As I understand it an 18-55 lens would enable me to zoom in 3x which wouldn't be enough for what I like to do (but probably sufficient for a lot of the things). "18" to me suggests quite a wide angle lens and "55" quite a small telephoto capability, at least in what I have in my mind as to how things work/been told before.

    FWIW - I enjoy walking and taking landscapes. If I see wildlife I enjoy zooming in and getting closer that way rather than walking nearer and disturbing them. I prefer to shoot without a tripod (so stupidly large zooms are out of the question and image stabilization of some sort is preferred). I also enjoy taking photographs of my family indoors running around and playing. I am a complete newcomer to SLR photography and have only ever had a point-and-shoot type camera but am wanting to learn more.

    Most of all, thank-you for all your help and suggestions so far!
     
  8. Helen B

    Helen B TPF Noob!

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    The smaller the format (ie the size of the sensor or film) the easier it is to design good quality zooms with a high zoom ratio. Your S5500 has a fairly small sensor, hence the ability for it to be fitted with a small, light 10x zoom.

    The S5500 has the equivalent of a 37-370 mm lens on a 'full frame' camera, in terms of picture angle. That means that if you were to use a 'full frame' camera like the Canon 5D or Nikon D3 you would have to use a lens capable of zooming to 370 mm to get the same 'reach' as your S5500.

    Here's a way of visualising the relationship between the focal length of the lens and picture angle:
    Cut a hole 24 mm x 36 mm (1 inch by 1.5 inches approx) in a piece of paper, and look through the hole.

    The angle of view of a 370 mm lens on full frame is the view you see through the hole when you hold it 370 mm from you eye. The angle of view of a 37 mm lens is the view you see through the hole when you hold it 37 mm from you eye.

    Now make a hole exactly half that size (ie 12 mm x 18 mm). To get the same angle of view as with the 24x36 hole at 370 mm you only need to hold it 156 mm away - half the distance.

    The size of the hole represents the size of the sensor, the distance from your eye represents the focal length of the lens. The 24x36 hole is the size of a full-frame sensor.

    You have quite demanding requirements for a single lens. Maybe your best bet is to go for a so-called 4/3rds camera. They have sensors about half the size of a 'full frame' camera, so you would need about a 150 mm lens to get the same 'reach' as your S5500 at maximum zoom.

    I'll stop there to get your reaction so far. There's plenty more to explain, and you are bound to have questions.

    Best,
    Helen
     
  9. Mav

    Mav TPF Noob!

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    Yes it's definitely a great lens for what it is, and has legions of fans in the Nikon world, and I'm sure Canon land also. :mrgreen: But it's not without its flaws. It's still a very complicated lens and sample variation is huge. Some people went through 2 or 3 before getting a "good one". The zoom creeps out if it's pointing down on some, but not on others. There's a good amount of vignetting. The bokeh is hideous. It has a professional level price, but just doesn't deliver professional level image quality. For the going street price of an 18-200VR at the time, I passed and funded myself a 55-200 and a trio of great prime lenses (35, 50 & 85). My shooting style just doesn't demand a one lens solution, but anybody else could be different.

    A lot of my issues with the 18-200VR can be fixed more or less in DxO software, which has a module for that lens on pretty much every reasonably current Nikon DSLR. But the bokeh is hideous, and nothing will fix that. Since I do a lot of people/baby type photography nowadays, I went with the Nikon 18-135 instead which is 1/3rd the price and has very nice looking bokeh.

    In a former life I was a globe trotting design engineer for some very well known companies. If I was into DSLRs back then and this lens was out, I would have had one in a second also. I was still screwing around with P&S's back then. I'm the type of guy that leaves his electric razor at home when travelling internationally just to save the few ounces of weight, along with a bunch of other little tricks, like leaving the camera charger at home gambling that I wouldn't need it (I didn't, heh he). So a one-lens solution is great for some, and would have been great for me how I used to shoot. :) That's why I say to not listen to me and to consider your own shooting needs, but to also be aware that you're making compromises to get the huge range. Depending on what you shoot, you may or may not care, so decide accordingly. (for travel photography where you usually want a lot in focus, ugly bokeh isn't gonna matter on 99.9% of your photos, so it's a non-issue for that type of photography)
     
  10. mostlycloudy

    mostlycloudy TPF Noob!

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    Thanks for the great explanation. It was very clear and easy to follow.

    I guess my questions now are what is a 4/3rds camera and how does a 18-200 lens such as the type Mav is suggesting fit into the picture?

    I forgot to mention, I don't necessary need a single lens to replace the camera but I wouldn't want to have to carry a whole bag-full around!
     
  11. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

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    Welcome to the forum.

    I think that one piece you are missing is lens quality and speed (size of maximum aperture).

    When they design a lens, especially a zoom lens, they have to make compromises. So, for the most part, if you have a 10X zoom (18-200mm for example)...the performance won't be as good as a 3x zoom (24-70mm for example). Also, a super zoom will usually have a smaller maximum aperture (larger F number). This can be a big disadvantage.
    To go one step further, the best quality lenses are often fixed focal length, often called 'Prime' lenses. They don't zoom at all. (50mm) for example. These lenses don't have to compromise image quality for zooming...so the quality is often very good and they usually have large maximum apertures.

    Part of the reason that photographers use high quality cameras (like DSLR cameras) is because they care about image quality...so it wouldn't make sense to use lenses that highly compromise the image quality.

    There are some exceptions...the 18-200mm Nikon lens, mentioned above, is said to be pretty good for a 'super zoom'...but the general rule is that the smaller the range, the better the quality will be.
     
  12. Helen B

    Helen B TPF Noob!

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    The 18-200 could work for you. Nikon's 'DX' sized sensors are about 2/3rds the size of full frame, so if you consider the angle of view it would be equivalent to a 27 mm to 300 mm zoom on full frame - ie slightly wider than the 37 mm to 370 mm equivalent on your S5500. Going from 37 mm to 27 mm is a useful expansion of the angle of view for indoor work. Maybe it is worth the loss at the other end. The list price at B&H is $680 It is a VR (vibration reduction) lens, and it weighs 1.2 lb. It would be fully functional on a D40 or D40x as well as the pricier and larger Nikon cameras.

    There is an Olympus lens for the 4/3rds system that is 18-180 - ie a 10x zoom. Because of the sensor sizes, this is like a 36-360 on full frame - ie much the same as your S5500. The list price at B&H is $425 for the lens, and it weighs about 1 lb - not much less than the Nikon. I don't know much about the features of 4/3rds cameras.

    Over to you.

    Best,
    Helen
     

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