[jaieger]

Hey, question on reversing lenses - if I understand it right, do I just buy something like General Brand 49mm TO 52mm Macro Coupler (Male to Male) AM4952 - and then screw in, say, my M50/1.7 to my kit lens or something, and go macroing away? If so, which lens should be the one attached to the body? And I feel like I have more questions but they're not coming to mind at the moment.

[jaieger]

Oh yes - how do people reverse lenses with just a single lens? Is there a different kind of adaptor required for that?

[rkohli]

Hey, question on reversing lenses - if I understand it right, do I just buy something like General Brand 49mm TO 52mm Macro Coupler (Male to Male) AM4952 - and then screw in, say, my M50/1.7 to my kit lens or something, and go macroing away? If so, which lens should be the one attached to the body? And I feel like I have more questions but they're not coming to mind at the moment.

You will need a K-mount to 49mm adapter for your M50/1.7.
Check this thread for more details
https://www.pentaxforums.com/forums/pentax-beginners-corner-q/60618-reverse-mount-adapter.html

Or you could buy an extension tube
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/47964-fa-50mm-...ens-macro.html

All the Best

[newarts]

1) Hey, question on reversing lenses - if I understand it right, do I just buy something like General Brand 49mm TO 52mm Macro Coupler (Male to Male) AM4952 - and then screw in, say, my M50/1.7 to my kit lens or something, and go macroing away? If so, which lens should be the one attached to the body? And I feel like I have more questions but they're not coming to mind at the moment.
...

2) Oh yes - how do people reverse lenses with just a single lens? Is there a different kind of adaptor required for that?

1) yes just buy a 49/52 macro coupler to reverse your 49mm filter lens onto
your 52mm filter lens ... also you might need a way to hold the front lens' aperture open.

2) Yes, there is a different kind of adapter for that.

[pacerr]

. . . question on reversing lenses . . . which lens should be the one attached to the body?

You have two issues here.

- To stack lenses, that is to use two lenses 'beak-to-beak', you'll need an adapter that matches the filter threads of each lens. If you have expendable filters of the correct size you can easily make your own adapter; remove the glass and carefully epoxy the two rings together as appropriate to 'stack' the lenses. The shorter focal length lens goes in front with the aperture set wide open. Stay with moderate focal lengths, i.e., a 35 - 50 in front of a 50 - 135 until you get a feel for the results.

- To reverse a single lens, you'll need an adapter that has filter ring threads on one side and the appropriate lens-to-body mount on the other. (yeah, like that shown below - thanks, Jeff. I was too lazy to shoot one.) These, too, can be a DIY project if you have the expendable parts. The most appropriate use for a reversed lens is when copying flat materials to moderate the curvature of the focal plane at close distances. An inexpensive set of extension rings is a more practicable and versatile solution.

Accurate focusing and Depth of Field issues will be challenging with either method.

Both types of adapters are cheap to buy and readily available but it's fun to experiment. I once epoxied a scavenged lens mount directly to the front of a cheap Sears F2/50 for a dedicated copy set-up and have a drawer full of DIY adapters. But if you're not havin' fun, it's a pointless exercise.

H2

[JeffJS]

Single lens solution..

[jaieger]

Hmm, okay. And also, what's the difference between the 3? Stacking lenses, extension tubes, reversing a lens. Yes, in one you stack lenses, the other you put extension tube(s) between the lens and the camera, etc., but in practice, why would I choose to, say, use extension tubes instead of reversing a lens, or vice versa? Does doing one yield a higher magnification than the other or something?

[bimjo]

1) Stacking lenses- you're using what's already in your bag (plus the adapter ring). You change magnification by changing the reversed lens. Two 50mm lenses gets you 1:1. Requires that the reversed lens have a aperture ring, or a means to hold open the aperture blades to take the shot.

2) Extension tubes- allows differing mag ratios by adding/subtracting rings. Can lose quite a bit of light. Can allow you to use a lens with a long minimum focus distance at closer distances. Can use any lens, though probably will have to manual focus.

3) Reversing a single lens- same issues as with stacking lenses- need an aperture ring for stop down metering or some method to hold aperture blades where you want them. Usually very small working distance compared to other methods.

Stop down metering (or green button) on 1&3, maybe on 2, depending on rings.

All three have their advantages and disadvantages. I have done all three at one time or another. You pays your money and takes your chances. Fortunately we aren't talking a lot of money so you can afford to experiment.

Keep in mind that when you reverse a lens you're exposing what is normally inside the camera to the elements.

[pacerr]

Hmm, okay. And also, what's the difference between the 3? Does doing one yield a higher magnification than the other or something?

The various methods allow for a wide range of magnifications depending on the amount of physical or "optical" extension and the lens focal length available. Unless you're accustomed to "setting up" your compositions based on field of view, depth of field and lens perspective there's little to choose between the methods - often it just depends on what you have available at the time.

As mentioned earlier, reversing a lens is specifically useful when a flat field of focus is necessary in copy work. Consider that a 'normal' lens is focusing on a very close, flat 'sensor' but the in-focus point(s) of a distant scene are on a curved plane at a fixed radius from the lens. Keeping the center and the edges both in focus with a shallow DOF at close range becomes an issue and reversing helps. It's cheap and easy to reverse a lens but it doesn't offer the versatility of extension rings (or bellows). You can easily explore this effect by simply holding a reversed lens to the camera body.

Stacked lenses also limit versatility and become cumbersome and 'nose-heavy' in use. Best used when extreme close-ups are needed with fixed set-ups IME. Again, just hold the second lens in front of the mounted lens to try it. I've made photos in the field by taping lenses together with electrician's tape -- keep it simple.

One option you might explore is the Vivitar or Panagor Variable Macro tele-extenders. Acting much like a "zoom" extension ring, both will give satisfactory results up to about 1:1 ratio with 35-70mm lenses and can be had with auto-exposure functionality. (Pick up a cheap PK-mount variable macro tube and a cheap M42 Sears 50/F2 lens on eBay and epoxy them together (concentrically of course, the M42 fits inside the K-mount) and go have fun.

The Raynox close-up lenses mentioned by Marc (and other multi-element diopter lenses) are also a versatile and economical solutions and easy to keep at hand in the camera bag.

You might find "Close-ups in Nature" by John Shaw and/or "Understanding Close-up Photography" by Bryan Peterson very helpful books. Reviews/previews available on Amazon. Search the net for "macro" or "close-up" plus any of the equipment terms and the articles section in this forum as well.

H2