John_F Loc: Minneapolis, MN

I have the Sony 30 mm E-mount macro lens and two zooms that range 18 - 55 and 18 - 135. When these zooms are set to 30 mm I don’t get a macro shot. Why be that?

robertjerl Loc: Corona, California

Macro has almost nothing to do with the length of the lens. It is how close it will focus so the image circle thrown on the sensor/film is 1:1 - life size.

imagemeister Loc: mid east Florida

Because they we not designed to do that - having to do with optics and mechanics. Special lens design ($$$) is needed to accompish this !
.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

The zooms will work - as long as you can get them further away from the sensor plane. You can do that with a bellows and/or extension tubes like these:

https://www.bhphotovideo.com/c/product/1048759-REG/vello_ext_sfed_deluxe_extension_tube_for.html

If you want greater than 1:1 magnification, you can even use these with the macro lens to get even closer to the subject. The downsides to using extension tubes are that you will lose some light as you move the lenses further away, and using an autofocus lens that is not designed for macro (or shooting at or near its minimum focus distance) may not provide the best image quality, and being an AF lens the rotation of the focus ring may only be 90°. Macro lenses usually have more "throw" on the ring so that you can fine tune focus easier. The advantages of using the extension tubes with your longer lenses will be increased working distance, which is especially useful when shooting natural, live subjects that might be spooked if you get too close.

Many newer lenses lack separate aperture rings, relying on the camera to set the apertur. In this case you'd need to use auto extension tubes so the camera can adjust the aperture.

Here are a couple of videos that demonstrate the use of tubes with lenses:

https://www.youtube.com/watch?v=ru7cMjrq9nA

https://www.youtube.com/watch?v=BsaP3nwGbsE

f8lee Loc: New Mexico

The actual reason you cannot get that close at the wide angle end of the zoom lens is that the shorter focal lengths afford shorter "working distances" - that is, the space between the lens and the subject.With prime lenses, you will find that wide angle lenses - even on extension tubes - just don't work...at really short focal lengths I imagine their close focus distance is behind the first element of glass.

Steve DeMott Loc: St. Louis, Missouri (Oakville area)

[quote=Gene51].....The advantages of using the extension tubes with your longer lenses will be increased working distance, which is especially useful when shooting natural, live subjects that might be spooked if you get too close.

Maybe I'm wrong, but extension tube will allow you to shorten your focusing distance and your working distance. Say my 50mm lens has a minimum focus distance of .35m. With a 25mm extention tube my focus distance will be less, lets say .28m, plus greater magnification. Doesn't that decrease your working distance?

If I misinterpreted your answer or my understanding of extension tubes please accept my apologies

--Steve

scsdesphotography Loc: Southeastern Michigan

In other words John f, because the minimum focusing distance is greater for your zoom lens than your macro, you have to stand further away at 30mm. While the field of view for both lenses is the same, the subject appears smaller because of your greater distance from it.

John_F Loc: Minneapolis, MN

Ah, there is the key fact getting the lens further from the sensor. Every sequence of spherical surfaces can be mathematically reduced to the lens formula. There are 4 cardinal planes: 2 focal planes and 2 principal planes. Subject distances, s, are measured from the front principal planes and sensor distances, s’, measured from the rear principal plane. s and s’ are related by the focal length in the equation,
1/s + 1/s’ = 1/f and magnification (object size)/(image size) = s/s’ . When the macro 1:1 number is inserted, s = s’ and 2/s (or s’) = 1/f which becomes s = 2f or s’ = 2f. My two zooms are too close to the sensor to do macro effectively, I gather.

Architect1776 Loc: In my mind

2666loco

The closer you get, the worse the macro lenses work. 50-100 mm is a good length for macro. You could also use closeup lenses for $15. A wide angle makes no sense for closeups due to distortion.

JD750 Loc: SoCal

It looks like you figured out the math.

To put it another way, as Imagemister said, the regular zoom lenses are not designed to reproduce 1:1, because they are not macro lenses. When you buy a macro lens what you are buying is close focus. Close enough to provide a 1:1 image. So a 50 mm Macro is not the same as a 50 mm normal lens. Yes same focal length, same field of view, but the macro lens will have a smaller minimum focus distance than the normal lens. There are some other trades too. The macro lenses generally have a finer focusing thread so they are not as fast focusing as a normal lens. Some macro lenses have selectors for focus range which helps with autofocusing.

If you want more information about macro photography there is a Macro section here on UHH:
https://www.uglyhedgehog.com/s-102-1.html

Drbobcameraguy Loc: Eaton Ohio

If you buy a lense reversing ring for about 8 bucks you can reverse the lense you have and get awesome macro shots. The dof is very thin. You must also manually focus and set your camera but it allows you to shoot macro for no money to see if you would like to invest in a macro lense and other equipment