Yo! I sometimes tire of re-typing some of the same helpful replies to the same excellent questions. I should write more articles, save my fingers a bit, eh? Here is a draft article on Cheap Macro. I'd like your comments and corrections before I submit it. Do your worst!
UPDATE: This draft is now dead. The official 'live' version is now here [ https://www.pentaxforums.com/forums/pentax-lens-articles/152336-cheap-macro-b...lose-work.html ] and all further comments should go there. Thanks for everyone's help!!
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CHEAP MACRO -- Buying or exploiting a lens for ultraclose work
I see many questions like, "Can you recommend a macro lens for under US$200 (or whatever)?" Well, it all depends on what you mean by 'macro' and 'lens'. :)
'Macro' usually means reaching 1:2 (0.5x) or 1:1 (1x) magnification. Reaching 1:1 isn't hard and needn't be expensive. 'Lens' can be anything from a superduper new multipurpose tool, to something you've salvaged from broken binoculars. The choice may depend on whether flash is needed. On a Pentax P-TTL-only dSLR, using flash can be tricky without an AF or other A-type lens. (Or maybe I'm just a wimp!)
The options:
* MACRO LENSES
* New or used AF macro lens -- not cheap, and you don't really need or want AF for macro work, but good for portrait and short-tele work as well as macro.
* Used A-type MF macro lens -- still not cheap, but you can easily use flash.
* Used non-A-type MF macro lenses, still not cheap (usually) and flash is tricky.
* FLASH-FRIENDLY TRICKS
* Lens extension with aperture control: A-type macro tubes or deglassed TC's.
* Closeup adapters -- very-to-fairly cheap, and you keep auto focus and aperture.
* Teleconverters -- macro-focusing or otherwise, A-type or not.
* EVERYTHING ELSE
* Lens reversal using a cheap mount-reversal adapter.
* Reverse-stacking using a cheap thread-reversal ring.
* Lens extension, totally manual, with cheap macro tubes and/or bellows.
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Some basics: No lens can focus closer than its focal length, and that point is also where you get maximum magnification. Short lenses are for close work. Longer lenses allow (or force!) you to work a bit further off. Macro lenses 60mm or shorter are generally for studio work; those 70mm or longer are more suitable for field work; those 200mm or longer can be a bit clumsy handheld. Fine macro work often requires flash and/or a tripod. Autofocus and fast lenses are NOT your friends when shooting macro. A-type auto aperture is handy, though. And except with close-up adapters, MACRO SHOOTING EATS LIGHT! For every X increase in magnification, you lose X+1 f-stops of light.
- DEFINITIONS:
- Clean Macro: No extra glass between the camera and the subject.
- A-Type: Pentax-A manual lens or extension, with auto-aperture contacts.
- MF: Manual focus -- AF: Autofocus -- all Pentax AF lenses are A-type.
- Flatfield Sharpness: Necessary for flat subjects; optional otherwise.
- Tricky Flash: trial-and-error; P-TTL flash is easier with A-type gear. MACRO LENSES: For 'dedicated' AF or MF macro lenses with auto-aperture control, you gotta pay. Pentax, Tamron, Sigma and others make popular macro lenses -- see the reviews. For 'dedicated' MF macro lenses without auto-aperture control, you still gotta pay. I have three fine manual macro lenses, by Kilfitt and Asahi and Vivitar-Komine... and I rarely use them, preferring to put lenses on CHEAP EXTENSION (see below).
PRO: Easiest to use; flatfield sharpness; for more than just macros.
CON: Fairly to quite expensive.
A-TYPE EXTENSION: With aperture-control extension, you use A-type macro tubes on your AF or A-type camera lens. Such tubes may be hard to find, and not cheap. But A-type teleconverters ARE fairly cheap, and their glass can be easily removed, and you retain aperture automation and thus flash support. These are usually about 25mm thick, so two of them on a 50mm AF lens puts you at 1:1. This is probably the cheapest way to do clean macro with flash.
PRO: Clean and simple; easy flash.
CON: Not quite as easy as macro lenses; eats light; not flatfield sharp.
CLOSE-UP ADAPTERS: Simple uncorrected meniscus +dioptre closeup adapters are cheap and are not great; but corrected adapters can give brilliant results -- see the Raynox Club thread. The fairly inexpensive Raynox DCR-250 reaches 1:1 at about 150mm on a couple lenses I've checked on my K20D. Your mileage may vary! That is, the exact magnification depends on the actual focal length and the focus distance. Adapters don't interfere with AF or auto-aperture; flash is no problem.
PRO: Very to fairly cheap; simple, easy; auto-control if desired.
CON: Imperfect image quality; not flatfield sharp; can be quite acceptable.___________________________________
SIDEBAR: +DIOPTRE CLOSEUPS
I call these 'strap-ons' and they range from cheap uncorrected meniscus screw-ins to the not-too-expensive corrected 2-element adapters from Raynox, and their ilk. Dioptres are additive -- stack +1+2+3 to get +6dpt. For reference, the Raynox DCR-150 is +4.8dpt and the DCR-250 is +8dpt.
The close-up attachment lens diopter selects the working distance, while the focal length of the host lens determines magnification. Here are focusing distances in inches and metric:
+1 >> 20-38" (500-950mm)
+2 >> 13-20" (330-500mm)
+3 >> 10-13" (250-330mm)
+4 >> 8--10" (205-250mm)
+5 >> 6.5-8" (165-205mm)
+6 >> 6-6.5" (153-165mm)
+8 >> 5" ---- (127mm)
+10 > 4" ---- (102mm)
Simple uncorrected meniscus strap-ons show aberrations, especially at the image edges, that you might not like -- no edge-to-edge flatfield sharpness, nope! But they can be OK for shooting rounded stuff head-on. And a +1dpt strap-on can turn a cheap slow 18-55 kit.lens into a decent portrait lens with thin DOF. These only cost a few bucks per set and are worth playing with, and FUN!
I mentioned adapters made by Raynox. These screw into supplied clip-on mounts that fit lenses from all makers on all cameras, as long as the host lens' front diameter is 52-68mm. The spring-loaded Raynox clip *can* be forced onto a 49mm-diameter lens, but I prefer to use a cheap 49-43mm step-down ring.
Most macro work eats light. Close-up adapters don't, and are good for dimmer shooting situations. Meanwhile, meniscus strap-ons can do other things, and other optical strap-ons and filters exist. Stay tuned for the article on those. [I'll link it here after I write it, soon...]
PS: Member PaleoPete posted his binocular lens macro rig. From his description that its working distance is about 5in, I can guess that the lens is about a +8dpt, like a Raynox DCR-250. Some of you experimenters with extra binocs lying about can try this CHEAP MACRO trick, eh?
___________________________________ TELECONVERTERS: Using teleconverters, you add glass between the lens and the camera. Ordinary TC's increase focal length (and f-stop) while keeping the same working distance, effectively increasing magnification. Macro-focusing TCs let you work closer and with more magnification. TCs magnify whatever problems the host lens may have. All TC's reduce the light reaching the camera. AF TC's are rare and expensive; A-types are less so; both of these are suitable with flash. I have some TCs. I don't use them; that's all I have to say about them.
PRO: Simple.
CON: Not the cleanest; eats light; magnifies lens problems.
LENS REVERSAL: Many macro shooters work with a reversed prime lens -- but reversal just brings you close to your subject. (Working distance is about 45mm with Pentax-type prime lenses.) You still need some extension to gain magnification. A lens with a deep front inset effectively has built-in extension; others may need an added tube. Lens-reversal is cheap, easy, and clean. Just about ANY lens can be reversed. That's how I recycle some non-Pentax lenses that I would otherwise not use. Or I can use a Pentax lens normally, for non-macro work, then flip it around to get real close.
You can reverse a zoom. DA lenses lack aperture rings; they won't do. But any FA or F or MF zoom can be reversed, with a working distance somewhere around 1.3-2x the focal length. Even a lousy zoom, reversed, can give good results. I do this with the A35-80, arguably the worst lens Pentax ever sold. At 35mm I get 1:1 magnification at about 5cm distance; at 80mm I get 1:2 magnification at about 15cm, and it will focus past infinity. A real macro-zoom! NOTE: Lenses labeled as MACRO-ZOOM, ain't macro. They rarely go beyond 1:5 magnification. But MACRO uses less ink than CLOSE-FOCUS so that's how lenses are labeled. Go figure...
PRO: Cheap and easy; flatfield sharpness.
CON: Close working distance; no auto control.
REVERSE-STACKING: You can reverse-stack lenses and can gain great magnification. Mount a longer PRIMARY lens on the camera; then use a male-male thread-reversal ring, then screw a shorter SECONDARY prime on that. (If you're really cheap, just use gaffer's tape to hold the lenses nose-to-nose.) Magnification is the ratio of the Primary:Secondary focal lengths. A 35mm secondary stacked onto a 105mm primary gives 105:35= 3:1 magnification. A 25mm stacked onto a 200mm gives 8:1, which gets into MICRO-photography territory.
The Primary can be a zoom, although I prefer primes. The Secondary should be a manual prime with an aperture ring. Use the Secondary's aperture ring to control exposure, and leave the Primary wide open. Stopping-down the primary can cause vignetting. You want the front objectives to be fairly close together; lenses with deep insets can cause vignetting. Space between the lenses will increase magnification VERY slightly.
Reversing or stacking primes ALWAYS puts you at that same close working distance of about 45mm. That is good for studio work; not so good for the field. Be sure to use a hood with any reversed lens, to reduce flare. HINT: Macro tube sections work well as hoods.
PRO: Easy to achieve great magnification; flatfield sharpness.
CON: Close working distance; no auto control; eats light.
CHEAP EXTENSION: I love simple cheap extension (tubes and/or bellows). You can put a prime or a zoom on extension for close and macro work; I prefer primes. An Industar-50/3.5 on 50mm of cheap M42 tubes with a safe cheap flanged M42-PK adapter puts you at 1:1 for a pittance. For not much more, is my favorite: cheap bellows and tubes mounting cheap enlarger lenses, copy lenses, other lenses without focusing mechanisms of their own -- non-camera lenses. You can shove just about any optical material into a bellows!
Many many types of tubes and bellows exist; I can't discuss them all here. I prefer cheap simple ones, and not only for macro work. Both PK and M42 tube sections can be used as adapters for weird lenses -- just glue a tube section to the lens body. Tube sets are dirt cheap, often well under US$10 shipped for 50mm of extension in 3 modular sections. I have about 6 sets of each and I need more. M42 bellows are cheap, PK bellows are a bit more. Bellows for other mounts can often be easily adapted to PK -- just replace the mount hardware with a cheap flanged M42-PK adapter.
PRO: Cheap; clean; flexible usage.
CON: No auto control; eats light.___________________________________
SIDEBAR: ENLARGER LENSES ETC
I love cheap enlarger lenses! EL's have edge-to-edge flatfield sharpness; they need hoods to avoid flare; they are FUN! A small bellows, some cheap macro tubes, and a handful of EL's will take you far. They also give me a great feeling of freedom. I'm not limited by whatever lens designers thought was A Good Idea.
On my K20D or K1000 I use a 50mm EL for close studio work; 75mm for slightly further macro work, and portraits; 90-110mm for portraits, and short-tele and moderate macro work; and 140-200mm for even more distance. I buy such EL's for under US$10 usually, sometimes four for a dime, maybe as much as US$20 for a Leitz or Nikkor. Premium brands can get expensive but the cheap guys work well too.
EL's have aperture rings, often with the numbers printed upside-down. Other lenses non-camera lenses can be put on extension: projector, copy, xray, process, other specialty glass. These typically DON'T have aperture rings. They can be used wide-open, or you can improvise baffles or Waterhouse stops for greater sharpness. Reversing an EL or other non-camera lens may increase sharpness also. EL and other non-camera lenses usually aren't designed for flare resistance, so be sure to use a hood.
Many European and some Japanese EL's have a 39mm thread, the same as M39 and L39 /LTM (Leica thread-mount) lenses. Some Japanese EL's have a 42mm thread, same as M42. Many USA EL's have inch-based or various non-standard threads. Some non-camera lenses have NO threads and must be taped or otherwise secured into adapters. Cheap adapter: a one-buck plastic body cap with a hole cut in it!
PRO: Cheap; EL's have flatfield sharpness.
CON: EL's rapidly become addictive!!
___________________________________ My recommendations: If you have the money and want a sharp versatile lens, get a new AF macro. (I'd love to crawl in the mud with a DFA 100/2.8 WR!) If you're real cheap and fairly lazy, get a set of meniscus close-up adapters; if not quite so cheap, get a Raynox. If you don't mind working real close, try lens reversal and stacking. If you want cheap clean basic macro, get a set of macro tubes or de-glass an A-type TC. If you want to experiment cheaply, get bellows and tubes and enlarger lenses. If 10x isn't enough magnification, get a microscope!
And there you have it -- the basics of Cheap Macro. I didn't say much about 'dedicated' camera macro lenses nor AF TC's because they ain't cheap! REAL cheapskates don't even buy macro tubes -- they get PVC pipe from hardware stores, and improvise. Online searches will reveal macro setups made from Pringles potato-chip cans. How cheap can YOU go? And I'm not discussing technique because enough is enough. I'll let the macro pros tell us how they do what they do, eh?
BIBLIOGRAPHY (actual books!)
FIELD PHOTOGRAPHY by Alfred Blaker (Freeman) ***
CLOSEUPS IN NATURE by John Shaw (AmPhoto)
CLOSE-UP PHOTOGRAPHY by William J. Owens (Petersen)
CLOSE-UP AND MACRO PHOTOGRAPHY by Adrian Davies (Focal)
UNDERSTANDING CLOSE-UP PHOTOGRAPHY by Bryan Peterson (AmPhoto)
Thanks to members jolepp, yeatzee, jatrax, abacus07, pacerr, GeneV, PaleoPete for suggestions. The fixes are in! The discussion thread for the draft version of this is here [ https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/152178-draft-a...eap-macro.html ] in case you want to read the comments.
UPDATE: This draft is now dead. The official 'live' version is now here [ https://www.pentaxforums.com/forums/pentax-lens-articles/152336-cheap-macro-b...lose-work.html ] and all further comments should go there. Thanks for everyone's help!! |
