Focal length - macro and telephoto?

[grantjames]

Hi!

I'd like to take both macro shots and also be able to zoom in close on far away objects. I thought I needed a macro lens and a telephoto lens, but now I'm. Not quite sure.

Is a lens considered a macro or telephoto lens by the focal distance (the numbers in the lens spec)? Im just really confused.

Any help would be greatly appreciated! Thanks!

 

[tirediron]

The ability to focus closely enough to a subject to produce a 1:1 image on the sensor (In otherwords, 1mm of subject size will be reproduced as 1mm on the sensor) is what constitutes a macro lens. Focal lengths above 50mm are generally considered to be telephoto lenses.

If your budget won't allow you to buy both (macro lenses being specialized and on the more expensive side), you may consider buying a moderate telephoto and a set of extension rings which will allow you to gain that close-focusing ability at a much reduced cost.

 

[Overread35]

You've got 3 terms in there that are getting a little mixed up - not least because of marketing departments abusing the meanings to put a spin on sales


Telephoto - this is a label used to mark any lens with a focal length that is greater than a set value. I forget what the value it (somewhere around 50mm I think) but simply put any lens that has a focal length longer than this value is telephoto.
In general talk telephoto tends to be used moreso on lenses at 100mm or longer and the words "super telephoto" are sometimes used for 300mm or longer lenses (however its also used for any really expensive telephotos).

Macro - this gets abused a lot. The strict meaning is when the lens is capable (at its minimum focusing distance) of reflecting an image on the camera sensor which is the same size as the subject is in real life (1:1). This is "true macro" and is correctly used on almost all the prime (single focal length) lenses on the market. A few (eg the canon 50mm macro) are incorrectly labeled because they can't get to the 1:1 ratio. Furthermore its a term that has come to be used on telephoto zoom lenses to denote that the lens has a closer than average focusing abilty - this is only around half life size at best (with some having significantly poor magnification abilities) and is a significant lesser magnification to the macro lenses.

Zoom - a horrible confusing term that the point and shoot market confuses things with. Simply put zoom refers to the minimum and maximum focal lengths of the lens and the factor by which you have to multiply the minimum to get to the maximim.
So by example:
18-200mm lens would be an 11times zoom - since 18*11 is roughly 200
300mm lens would be a 1 times zoom because it has only one focal length, so nothing to multiply by.

Thus you can see that without knowing the shortest focal length the term "zoom" falls out of use because it does not always mean that the lens is longer than others if you compare just the zoom factors.


In short if you want a longer lens for wildlife or sports you want to look at the focal lengths where the longer the better is the very general approach. Whilst if you want a macro lens you can look at some zoom lenses (eg a sigma 70-300mm APO macro) if subjects the size of flower heads are roughly what you want to shoot - but for true macro you have to stick to the prime lenses.

 

[djacobox372]

It should be noted that there is no standard for the use of the term "macro" on a lens; many 3rd party lenses that claim to be "macro" don't focus at 1:1.

 

[fokker]

IF you're on a budget and looking for an all-in-one macro/telephoto then check out the sigma 70-300 macro lens, it's pretty cheap and if you get a good copy it can produce some acceptable results. Having said that, you pretty much always get what you pay for.

 

[Overread35]

The general use of macro by 3rd party companies (and own brand ones) is to denote true macro capable prime lenses as well as the close focusing zoom lenses. The sigma 70-300mm macro is a clear example of the latter. Its a zoom with macro in the title, but its overall magnification only gets to 1:2 -half life size which makes it an ideal flower portrait lens, but hopeless if you want bee and fly portraits.

 

[grantjames]

Thank you to everyone for their replies. You have all made things a lot clearer for me.

Originally I was under the impression that there were wide angle lenses, macro lenses and telephoto lenses. Wide angle having a focal length similar to 18 - 55mm (like the one that came with my 1000D), and then telephoto lenses being 100mm+.

So by that logic, I thought to focus on tiny close up objects I'd need a "macro" lens, with the focal length being something like 10mm or smaller. Sounds a bit strange now but I think you can tell I was definitely getting my terms mixed up!

So just to clarify, if I buy a telephoto lens, will I take pictures of quite small objects, simply, by standing a distance away from them and then zooming in close?

I don't have anything specific I'd like to photograph yet, but I'm really keen on doing some nature photography.

Thanks again! I really appreciate it!

Edit: Also, would someone mind explaining how extension rings/tubes work? Thanks!

 

[Overread35]

First I'll clarify one thing on macro that I've neglected to specifically point out - within the prime (single focal length) macro lens range all the lenses (barring th odd one like the canon 50mm macro) achieve at their closest focusing point, the same magnification relative to the sensor.
So on that score because the magnification is the same a 60mm macro lens and a 150mm or even 200mm macro lens will -at its closest focusing point - give you the exact same image framing. You won't get any more "zoom" or magnification with one over the other.

The difference is that the physical distance from sensor to subject will be longer on the longer focal length macro lens - plus the longer lenses will give more blurring to the background areas of ashot.

So just to clarify, if I buy a telephoto lens, will I take pictures of quite small objects, simply, by standing a distance away from them and then zooming in close?

Depends on the small
If you're shooting little bluetits or other small birds then yes the longer the focal length the further away you can be to take the shot. However if you mean flies and smaller things then chances are you just won't be able to get the shots with any zoom lens with macro in the name.

 

[grantjames]

Perfect, I think I fully understand now.

I don't plan on taking pictures of things as small as flies, but yes photographing things like flowers and other animals etc. with a shallow depth of field is what I want.

One last question (I already appreciate the help so I don't want to abuse everyone's kindness!) I have looked at the Sigma 70 - 300mm APO lens as suggested above (around £180 - £200), and have noticed there is also a Sigma 70 - 300mm (without the APO in the title): Sigma AF 70-300mm f4-5.6 DG Macro Canon Fit Lens: Amazon.co.uk: Electronics for around £120.

I've found out that the APO one "minimizes colour aberration", but does anyone know if spending the extra £80 is worth it for this feature (bearing in mind I am a hobby photographer and still relatively new to it all).[FONT=Arial, Helvetica, sans-serif]
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[Overread35]

The APO edition is also noticably sharper at the longer end of the lenses range - so yes it is well worth the little bit extra to the price.

Also you might find the following diagram in this thread of interest : Juza Nature Photography Forum • View topic - Working distances for bird photography