Macro f2.8 vs prime f1.8

Pinksummer27

Firstly, can you use a macro lens to take a "regular" photo too like a portrait? Secondly, is 1 f stop a huge difference if you shoot moving targets in low light? I'm looking at the sony 30mm macro f2.8 vs 35mm prime f1.8.

MarkR

Pinksummer27 wrote: »

Firstly, can you use a macro lens to take a "regular" photo too like a portrait? Secondly, is 1 f stop a huge difference if you shoot moving targets in low light? I'm looking at the sony 30mm macro f2.8 vs 35mm prime f1.8.

You certainly can use macro lenses as portrait lenses. They are great-- sometimes they are too sharp!

My own experience has been that ultra-fast lenses need to stop down a bit before they start getting acceptably sharp, and that macros wide open just start out sharp and get sharper.

However, if the macro does not have a limiter, you may find that missed focus will cause it to rack across the entire focal range before it finds focus again. Not too bad for portraits, but more "moving targets in low light" you might end up missing some shots.

No experience with the Sony lenses, but I have used a Pentax 35mm macro as a walk-around lens very effectively for a number of years.

Pinksummer27

Thanks. Can you explain what a limiter is? Also what does rack across mean? Much appreciated!

MarkR

Pinksummer27 wrote: »

Thanks. Can you explain what a limiter is? Also what does rack across mean? Much appreciated!

Macro's have a much greater focal range than most other lenses. Therefore it can take longer for them to autofocus if they have to run the entire focal range-- a few inches to infinity. If it can't find focus, it may then hunt or rack back through the entire focal range again. This can be very frustrating.

Some macros have a limiter that you can turn on which, as the name suggests, limits focus to either macro (close focus) range or to normal working distances. This helps speed up the AF by limiting the range the AF is looking at.

Just a quick point too-- at 30mm, you'll probably be frustrated if you are trying to use the lens as a "true" macro. It'll be good as a general walk-around lens because your working distance is however close you can get your lens to your subject. However, at closest focusing distance, you'll be right on top of your subject, which will reduce the amount of light your lens will get. (no good for bugs and critters!)

Pinksummer27

Thanks. What size macro lens is good?

MarkR

Pinksummer27 wrote: »

Thanks. What size macro lens is good?

It depends on what you are photographing! If you are just doing product photos, or walk-around photos any focal length is fine. If you're trying to take pictures of critters (bees, bugs, butterflies) you'll need much greater working distances. I liked my Pentax 100mm for those kinds of shots.

ziggy53

I too prefer focal lengths of 100mm-ish for macro photography. This focal length also translates pretty well for many types of portrait photography (since Pinksummer mentioned that earlier.)

Any true "macro" prime lens close to 100mm and with f2.8, from most manufacturers, should be pleasant to use for macro photography. A lens with faster focus motor technology would be more suited for general portraiture as well.

pathfinder

This is an old thread and kind of rambles about, but it discusses the trade offs in macro lenses, extension tubes, and macro adapter filters.... http://www.dgrin.com/showthread.php?t=25165&highlight=macro+lenses+Pathfinder

paddler4

macros are the only case I know of where the question 'how long is good' can SOMETIMES be answered without knowing the camera you are shooting.

If you are shooting at minimum working distance, the sensor size does not matter. MWD is whatever it is, regardless. The image just fills more of the sensor if the sensor is small. (However, if you are not working at MWD, and instead want to fill the frame, then I think the sensor size does matter because of the smaller field of view of a smaller sensor.) With a crop sensor camera, I usually use a 100mm for bugs, although I have shot plenty with a 60mm. More often than not, I use the 60 for flowers because the shorter working distance is handy on a table.

davev

I've owned a 50mm macro f2.5 for years and hardly ever used it.
I've done a few portraits with it, and they turned out very well.
Just a day or two ago, I hooked it up to my Sony Nex7 via an adaptor.
It works very well on that camera. Although it's manual focus, (cause it's on the Sony)
I think with macros that's the way to go anyways.
The fact that the Sony has a Peeking mode for focusing makes it very easy to use.

Anyway, what was said about the paper thin depth of field is very true.
This is a shot at min focal distance (about 9") of the 52mm cap for that lens.
It was taken wide open at f2.5.



A link to a vid showing Peeking Mode focusing. LINK
The part that is yellow is in focus.
Canon needs to come up with something like this.

So, 50mm f2.5, good for macro, good for portraits, but auto focusing is slow when used as a regular lens.

I mounted my 50mm f1.8 on the sony for a quick shot just to show you the difference.
This is min focal length again, but somehow I did manage to miss the "Canon" on the lens cap.
Both of these shots are the full frame straight from the camera.



Hope this helps.

MarkR

I did some looking around at photozone.de, and quite frankly of the two lenses the OP asked about, the f1.8 compares strongly to the macro in terms of sharpness, vignetting, etc-- and it close focuses to 1:4, which is probably as close as is practical for a lens of that focal length anyway.