Macro Lenses Vs. Prime Lenses

[decado]

What are the difference between a macro lens and a normal prime lens? For example, what would the difference be between a 50mm macro lens and a 50mm prime lens?

 

[Josh66]

Macro can focus closer. 1:1 usually.

Non-macro lenses usually do around 1:5, or 1:6 - something like that.

At 1:1 the object you are photographing would be life size on the sensor/film.

 

[decado]

Macro can focus closer. 1:1 usually.

Non-macro lenses usually do around 1:5, or 1:6 - something like that.

At 1:1 the object you are photographing would be life size on the sensor/film.

What do you mean by focusing 1:1?

 

[Josh66]

Reproduction ratio.

1:1 means life size. A postage stamp would fill the entire frame (for example).

1:5 would mean that the same postage stamp would be 5 times smaller than life size on the sensor.


Basically, it's how close you can focus. A macro lens can usually focus on something less than a foot in front of it, a non-macro lens can usually only get down to around 3 feet and still focus.

 

[Josh66]

Glad to hear you're using this: I plan to keep it much more aggressively up-to-date than has been the case in the past, but don't hesitate to let me know if you find errors or need clarifications.

What are you talking about?

 

[c.cloudwalker]

Sorry Josh. Although your explanation of a macro is correct, it does not really answer the OP's question since you forget to mention that a 50mm could/can be both macro and prime at the same time.

To the OP, one has nothing to do with the other. A macro is as Josh explained. A prime, also known as a fixed focal lens, is the opposite of a zoom. A zoom covers a focal range, 24 to 85 let's say which, in this case, includes the 50mm focal length. But a 50mm will never be anything but 50mm.

Now, a 50mm prime can be either macro or not.
And same with a zoom. The 24-85 I used as an example can also be either macro or not.

 

[Josh66]

Sorry Josh. Although your explanation of a macro is correct, it does not really answer the OP's question since you forget to mention that a 50mm could/can be both macro and prime at the same time.

I almost mentioned that, but I thought he might have known that based on the wording of his post... Just a bad thread name I guess.

 

[Derrel]

Besides being able to focus closely, short macro lenses (like 35,50,55,60 mm for example) are also often described as being "flat-field", which means that they have a perfectly flat focusing band, and do not suffer from the optical design flaw called "curvature of field". Curvature of field imparts an unusual look to image shot where the curvature is really high or bad; it gives a weird effect, with a sharp center image area, surrounded by a more than normally out of focus, slightly blurred periphery.

On many high-speed lenses, like Canon's 85mm f/1.2L, or Nikon's 35mm f/1.4, just for two specific samples, the center of the frame can be in super-sharp focus, but the focus will not be sharp at the periphery of the image, due to curvature of field. Since short macro lenses are frequently used for copying of documents, stamps, and artwork like paintings, the designers of macro lenses strive to have perfect flatness of field.

What might seem odd to some is that there are some *very* sharp and very costly lenses made by Canon, Nikon, and Zeiss, but which display very high degrees of field curvature, which can be used for creative effects, like on the $1,000 Zeiss 28mm f/2 Distagon reviewed here.

The Online Photographer: Zeiss ZF / ZK Distagon T* 28mm f/2 Review

 

[c.cloudwalker]

and the quishi post is spam

 

[decado]

Sorry Josh. Although your explanation of a macro is correct, it does not really answer the OP's question since you forget to mention that a 50mm could/can be both macro and prime at the same time.

I almost mentioned that, but I thought he might have known that based on the wording of his post... Just a bad thread name I guess.

Ya, I suppose it was bad thread naming.

So, if I get a 50mm f/1.4 will I still be able to use that as a macro lens and just stand back farther or will I have problems getting frame filling shots?

 

[c.cloudwalker]

So, if I get a 50mm f/1.4 will I still be able to use that as a macro lens and just stand back farther or will I have problems getting frame filling shots?

No, you need a macro lens.

 

[Josh66]

No - the 50mm f/1.4 is NOT a macro lens.

You just can't fill the frame with very small objects. It's fine for everything else.
Minimum focus distance for that lens is 1.5 feet, so something like a person's face would fill the frame, but not a penny.

 

[Battou]

The difference is minimum focusing distance and max aperture, I happen to have both a Canon Macro 50mm 3.5 and a Canon 50mm 1.4.

The minimum focusing distance on the 50mm 1.4 is about 0.45 meters wile the Macro is about 0.232 meters...of course these are the 50mm lenses I have....some lenses may vary.

 

[Overread]

A few other points to add:

1) Macro lenses not only focus a lot closer than a regular lens, but they also have a much finer control over the focus. The focusing ring which you turn will travel further round, but will focus slower than on a regular lens - that lets you have very precise control over the focus. I should also note that this is true only of the closer focusing distances - once you start focusing on further off subjects the ring will turn at a more normal rate

2) Partly as a product of the above and also because auto focus is not a primary requirement for macro work (most is done in manual focus) the macro lenses tend to have poorer AF than regular lenses. Its still usable, but is often a lot slower than a regular lens. You can use a limiter switch to cut out a section of the focus wheel (all those close distances) but it will still be slower.

3) Macro lenses come in 2 sorts - macro lenses which are primes (single focal length) and macro lenses which are zooms. The prime macro lenses are mostly "true" macro lenses - that is they achive the 1:1 magnification ratio when focused as close as they can to the subject (an exception is the canon 50mm macro which is only a 1:2 macro (half life size) and needs an adaptor to get to full 1:1).
The zoom macro lenses are all not true macro lenses, it is a marketing move to include the macro title and simply means that they have a closer focusing mechanism than most other zoom lenses. Typically the best you will get is 1:2 but even 1:3 and smaller are possible under this title.



Also you ask the question of if you can use a regular 50mm lens as a macro and the answer is infact yes - BUT you need something to reduce its minimum focusing distance - something to let it move closer to the subject and thus cover more of the sensor with the image. This can be done in 2 ways:
1) Extension tubes - these move the lens away from the camera and as a result they reduce the minium focusing distance of the lens - thus letting you focus closer. Typically these tubes come in a range of sizes (quoted in mms) and to get to 1:1 magnifcation you need to add as many mm of tube length as you have mm of focal length - so 50mm of tubes for a 50mm lens, 100mm of tubes for a 100mm lens**
This will come at a cost though, you will lose infinity focus and that means that you will only be able to focus on things up to a few feet away (or less depending on tube length added and the lens used).
The best sort of tubs to get are Kenko AF tubes, since tubes contain no glass at all the kenko off far more for your money since they come in a set of 3 tubes, whilst official canon and nikon tubes will only come as a single tube length and each of those will cost as much as a set of 3 from kenko. There are even ultra cheap tubes ($/£5) on the market, but these do not have any contacts in them and thus your camera will not be able to detect nor control the lens attached - you lose AF (though not a problem as macro focusing is done in manual) but you also lose the abilty to change the aperture on the lens - something that you will need to be able to do for macro.

2) A macro diopter (or filter or lens attachment) - these work the same as the tubes, but operate by a glass element which screws onto the front of the lens (like a filter). There is again a range of these from the ultra cheap (and bad) to the very good - personally I would strongly recomend options like the Raynox range (DCR 250 is a popular choice).

Image quality wise both the tubes and the diopters will cause some image quality loss but in most cases (when using good quality diopters) this will not be a problem and other factors such as user error, lighting, subject movement etc.. will be far more damaging to image quality.


**note this is a rough calculation, the actual numbers are slightly less, but the rule of thumb is close enough for most needs

As a final point on macro lenses - they all achive the same level of magnification - that of 1:1, but if the lens has a focal length of 50mm you will have to be closer to the subject to get to 1:1 than if your lens has a focal length of 100mm. Thus for work with insects it is often recomended that people start with a macro lens of at least 90mm or longer so that they have a longer distance between the subject and the camera (called working distance). It is fully possible to use a shorter focal length lens for this work, but it is more challenging especailly when one is new to working in macro.

As a final point if your interested in a 50mm lens which will do both macro and regular shooting avoid the canon 50mm macro (as said earlier its not a true macro lens) and instead look to options such as the sigma 50mm macro or the canon EFS 60mm macro (note that EFS means that it will not work on a fullframe camera like a 5D, but if your not upgrading to a 5D its certainly not a worry and the EFS 60mm is one of the best EFS lenses).

 

[Battou]

I have some things to add to Overread's post too, Including (but not limited to) some example photos for both a standard 50mm prime used for macro as well as a macro 50mm prime. but considering I am short on time I'll have to get into it later on.