Beginner 70-300 vs 18-200 zoom? magnification?

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mee how

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Michal
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Hi
Could you please explain what difference is between 70-300 and 18-200 lens in a sense of zoom or magnification.
Lets assume both lens are focused at 200mm.
Optical Zoom difference is 4.3x to 11x.
Would either image be actually 'larger' or sharper.
Help me understand please.
 
mee how said:
Hi
Could you please explain what difference is between 70-300 and 18-200 lens in a sense of zoom or magnification.
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18 is very wide, good for landscape photography. 70 would be more useful for portrait. The 300 mm lens will have better telephoto capabilities.
Lets assume both lens are focused at 200mm.
Would either image be actually 'larger' or sharper.
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In theory both lenses set to 200 should produce similar results in terms of zoom and image size. The 18-200mm lens, as it's at it's limit may be less sharp as it's on it's limit, or show fringing towards the edges of the image (this is what to look out for), but this depends on the quality of the optics in the lens. I have a Tamron 18-270 and a Canon 70-200 f4 L and the opposite is true as the L series lens has far superior optics. The lens with the 18-200mm capability would likely suffer at it's limit because of it's wide range, usually there's a compromise.
Optical Zoom difference is 4.3x to 11x.
Help me understand please.
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I wouldn't get hung up on the optical zoom factor, while what you say is correct, using optical zoom = maximum focal length / minimum focal length equation, this makes it look like the 18-200 has the greater zoom, in reality the 300mm lens will have the best reach. If you needed one of these for nature photography, the 70-300 zoom would be the best choice, even though it's only 4.3x.

I hope this helps.
 
Any lens, or zoom lens set to 200mm is a 200mm lens...the FL has nothing to do with larger or sharper. If the photographic subject is say 20M away either lens of the two lenses you mention set to 200mm will fill the frame equally (on the same camera).

Can I suggest you explain what it is you are expecting of your choice of lens and why you have asked this question?

Edit ~ slow posting and @Egg1000 has covered it more comprehensively......but my question still stands!
 
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mee how said:
Could you please explain what difference is between 70-300 and 18-200 lens in a sense of zoom or magnification.
Lets assume both lens are focused at 200mm.

Would either image be actually 'larger' or sharper.
Click to expand...

Extended to their longest length the image from the 70-300 will be larger than the image from the 18-200.

Sharper will depend on a lot of things, not least the specific models of lens being compared, so there is no definite answer to that.
 
I have both in the Nikon brand .. 18-200 is ok as a general walkabout lens for holidays .. dont expect great distance in zoom though ... the 70-300 is not good for holidays as its too heavy and the 70mm distance is too long for around town photos .. its not a bad beginners lens for nature though .. I have taken some great shots from the cliffs in Wales .. the 70-300 seems slightly sharper at 200 as well .. I think it has better quality glass than the 18-200 .. what are you intending to use them for?
 
The intended purpose is face recognition at a distance.
I was able to work successfully with 70-300 at up to 75 meters.
Struggling at 100 meters.
I was wondering if 18-200 will allow me to reach further.
Now, I see that it is not as simple as the supermarkets 25x zoom or 50x zoom when it is obvious the 50x zoom will have 2x the reach!
I understand now that the 11x "zoom" of 18-200 is not 2.5x as powerful as 4.3x "zoom" of 70-300.
Follow up question:
What lens will double the reach of 70-300 so I could work face recognition at 150 meters?
There are some "2x zoom" attachments available.
Do they actually work?
 
Forget "zoom range", it is Focal Length that you need!

If 300mm is too short then you need 400mm, 500mm or 600mm......but these have consequently higher prices.

There are some cameras e.g. Panasonic FZ1000 (if I have recalled the make & model correctly?) that has max zoom of 1200mm. NB such cameras use a very small sensor so other factors come into play. But suffice to say the zoom range in small format camera is huge.

HTH

Edit ~ sorry the FX1000 has max 400mm and the FZ200 has max 600mm......there is such a bridge camera that has the 1200mm. When/if I can re identify it I will update this post.
 
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At 200mm the lenses will offer the same field of view. Which would be optically better would depend on the lens design.

Other than that... The 18-200mm looks like it's an APS-C lens whereas the 70-300mm could be either an APS-C or a full frame lens.

Egg1000 said:
18 is very wide, good for landscape photography. 70 would be more useful for portrait. The 300 mm lens will have better telephoto capabilities.
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18mm is wide on FF but this looks to be an APS-C lens which would equate to something like 28mm on FF which isn't all that wide really. Maybe wider than what most people would consider for "normal" lens but not anywhere near as wide as 18mm would look on FF.
 
The problem is that zoom and zoom range aren’t interchangeable terms.

The zoom range you’re talking about doesn’t translate to reach.

When manufacturers or resellers talk about 4x zoom range, they’re not talking about 4x magnification. It’s simply a way of describing the difference between the longest reach and the shortest. So they simply divide the higher figure by the lower one.

So 200 divided by 18 gives you 11.11111111

Whereas 300 divided by 70 gives only gives you 4.28.

Irrespective of that, the 70-300 lens has the biggest zoom. if you want reach you want the highest figure possible.

It’s a weird way to describe lenses as there’s no constant. Hence why you get odd comparisons.

As mentioned above, both lenses set to 200mm on the same camera body should produce images that are the same in terms of size.

The difference will come in the quality (and usually price) of the lens. As a general rule of thumb, the greater the zoom range (i.e. the 11x magnification) the lower quality the image will be. So all other things being equal, at 200mm I suspect the using the lenses you're talking about, the 70-300 would give the sharper image.
 
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From 150m away, to get a full body length person in portrait orientation on a crop sensor camera you'll need a focal length of 1200mm
To get a full body length person in landscape on the same camera you'll need 800mm lens.
You'll also need good technique and an element of good luck, as shooting that distance over tarmac on a warm day may well encounter heat haze.

Fortunately Nikon will sell you an 800mm lens for £ 18,000 RRP.
 
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Re: 1200mm on a bridge camera

It is the Panasonic FZ82
 
The 2x zoom options seem like a good way to increase the reach of a 70-300 mm lens to 140-600mm for far less money than buying a 600mm lens.

But that's because not all things are equal. When you add one of these extenders or teleconverters, you don't just double your focal length, you have to double your f/stop figures as well.

See: https://www.nikonimgsupport.com/ni/NI_article?articleNo=000002347&configured=1&lang=en_US

My old Canon (non L series) lens 70-300mm lens was F4/5.6. Stick a teleconverter on this and use it at an effective 600mm and all of sudden, you lose two full stops so the widest aperture you could use is equivalent to f/11. This causes other problems with diffraction, slower shutter speeds introducing blur, and the end result wouldn't be as sharp as using a dedicated lens.

There is some maths at play here, because the f in your f/stop number is the focal length of the lens and it's all part of a longer equation where the focal length is divided by your f stop to give you the diameter in mm of the opening of your aperture.

So in the case of my lens above 300/5.6 means that the aperture of the lens would open up to 53.5714286 mm. This is a fixed size, maximim opening and doesn't change if you stick a teleconverter on. So in order to make the equation balance, if you double the focal length, you double the f/number. Or to work it out you take the 600 and divide it by the aperture opening. 600/53.5714286 mm to give an f/stop of 11. (It would actually be 11.2, but that doesn't exist).

www.clickandlearnphotography.com

F-Stop Chart Infographic / Cheat Sheet

Many beginner photographers struggle to get to grips with the concept of apertures and f-stops, but we’re here to clear up any lingering confusion! Click here for our handy, easy to understand F-Stop Chart infographic....
www.clickandlearnphotography.com

When I studied photography, I was always told that the cheapest zoom is your legs.

Can you not get closer?
 
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Kell said:
When I studied photography, I was always told that the cheapest zoom is your legs.

Can you not get closer?
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I hope they also told you that changing the camera to subject distance changes the perspective and pictures taken at 20mm and 300mm with the subject the same size in the frame will look very different.
 
woof woof said:
At 200mm the lenses will offer the same field of view. Which would be optically better would depend on the lens design.

Other than that... The 18-200mm looks like it's an APS-C lens whereas the 70-300mm could be either an APS-C or a full frame lens.



18mm is wide on FF but this looks to be an APS-C lens which would equate to something like 28mm on FF which isn't all that wide really. Maybe wider than what most people would consider for "normal" lens but not anywhere near as wide as 18mm would look on FF.
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Absolutely no mention of camera type or lens fit type by OP.
 
Egg1000 said:
Absolutely no mention of camera type or lens fit type by OP.
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Thanks for reminding me that I spotted that when I posted at 12:34 pm today but just to be sure can you think of a format apart from APS-C that has a 18-200mm lens?
 
woof woof said:
Thanks for reminding me that I spotted that when I posted at 12:34 pm today but just to be sure can you think of a format apart from APS-C that has a 18-200mm lens?
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No, but if a lens is APS-C and the camera is APS-C then 18mm is 18mm. If it's a lens designed for a crop sensor, then the focal length is relative (and 18mm is wide).
 
Egg1000 said:
No, but if a lens is APS-C and the camera is APS-C then 18mm is 18mm. If it's a lens designed for a crop sensor, then the focal length is relative (and 18mm is wide).
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No, it isn't very wide.

If it's an APS-C lens on an APS-C camera it'll give a FF equiv FoV of about 28mm. As I said above. This isn't very wide or even particularly wide. As I said in response to an earlier post. It is wider than a 50mm lens and it's probably about the FoV your smartphone gives but it isn't very wide when compared to.... oh what can we use as a comparison? How about an 18mm lens on a FF camera? If you want a 18mm FF equiv FoV on APS-C you'll be looking for a 12mm lens.

Swapping posts with you on this has been most enlightening but it must end soon so please tell me, what part of this don't you agree with?
 
woof woof said:
If it's an APS-C lens on an APS-C camera it'll give a FF equiv FoV of about 28mm.
what part of this don't you agree with?
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This.
No one mentioned FF equivalent. Canon 18-50mm EF-S kit lens is good for landscapes on 18mm (using an EF-S camera), feel free to disagree.
 
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Egg1000 said:
This.
No one mentioned FF equivalent. Canon 18-50mm EF-S kit lens is good for landscapes on 18mm (using an EF-S camera), feel free to disagree.
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Egg1000 said:
Are you sure you're not getting your wires crossed? The crop sensor factor (and calculations) are only an issue when you're using the same lens on different cameras.
For example, my nifty 50, f1.8 which is EF fit. I appreciate that on a FF camera this is true 50mm. But on a crop sensor camera, it is more like a 70mm.
But that is not the same as my lenses designed for a crop sensor. 50mm with my EF-S lens is not the same as 50mm on the EF. It's wider. If I put an 18mm FF lens on a crop sensor, then yes it would be more like 27mm, but not one designed for the camera. It's not how the crop factor issue works.
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If you look above you'll see that I had two basic points. Firstly that the lenses would give the same FoV (at 200mm and this is all assuming this is on the same camera) and the OP seems to be talking about APS-C as a 18-200mm is mentioned and... Secondly as someone said that 18mm is "very wide" I posted that on APS-C it isn't and that's true. 18mm on APS-C isn't "very wide" even though as you quite correctly say 18mm is 18mm but you have to consider the format which affects the FoV and 18mm on APS-C simply is not "very wide" and anyone thinking it is probably hasn't used a wider angle lens. As another example I have a compact with a 6mm lens and that isn't "very wide" either.

Your opinion about the Canon 18-50mm being good for landscape is your opinion and I'm not expressing any view on that.

And with that I'm out for good this time as these are probably relevant points to the OP and if the OP does come back and sees all this it'll probably put them off posting again.
 
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woof woof said:
I hope they also told you that changing the camera to subject distance changes the perspective and pictures taken at 20mm and 300mm with the subject the same size in the frame will look very different.
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There’s a massive difference between scratching your @rse and taking the skin off.
 
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