Re: Macro Extension Tubes
[EMAIL PROTECTED] (Village Idiot) wrote: >Wow. Thank you for the information Mark, it helps a lot. I am definitely >going to get myself of extension tubes now. > >Thanks again for the help and the enablement, When Mark Cassino talks about macro, people listen! (As well they should) -- Mark Roberts Photography and writing www.robertstech.com
Re: Macro Extension Tubes
Wow. Thank you for the information Mark, it helps a lot. I am definitely going to get myself of extension tubes now. Thanks again for the help and the enablement, Derek > I use extension tubes all the time - a few basics: > > 1. A lens's focal length is that distance at which that lens will focus at > infinity. Multiple element lenses complicate this a bit, but in the most > simple terms a 100mm lens, for example, will focus at infinity 100mm from > the film plane. That's why it is called a 100mm lens. :-) > > 2. As you move the lens further from this point, you move the plane of focus > closer. A lot of lenses focus by just moving the a bit further out from the > film. This moves the lens off infinity focus, and lets you focus closer. > > 3. The point at which the extension of the lens equals the lens's focal > length results in a magnification of 1:1 - i.e. the image on the film is the > same size as the object itself. So - with a theoretically simple 100mm, that > is focused at infinity when it is 100mm from the film, if you add 100mm of > extension, the lens will now focus very close, and the image on the film > will be the same size as the object photographed. > > 4. When you focus closer, you magnify the image. Understanding the optical > effects of magnification is they key to understanding macro and close up > photography. Everything else is just derivative from the impact of > magnification. > > 5. Every lens has aberrations and distortions. When you add extension and > magnify the image, those aberrations and distortions are also magnified. In > theory, macro lenses have been designed to overcome these problems. I have > yet to see a situation where a non-macro lens matched a macro lens in > performance at high magnification (greater than 1:1). That said, some > lenses - like the Pentax 50mm f1.7 M, A, F, or FA, (all the same optical > formula) do work very well with extension. > > 6. There's no problem using tubes with Digital SLRs. I use Vivitar tubes > that have the full contacts, and with A or later lenses I loose only > autofocus. I also use tubes and bellows for snowcrystal photos - lots of > tubes. In that case I rely on the TTL flash to control the exposure. Pentax > does not make tubes with contacts needed for auto exposure / aperture > control, but third parties do. The thing with tubes - you can buy just plain > tubes with no contacts and no mechanical connector to stop down the lens, > you can get them with just the mechanical connectors to control the aperture > but no electronic contacts, or you can get them with both mechanical and > electronic contacts. The latter will result in an A or better lens working > fine with a digital SLR, except that you will have to manually focus. > > 7. A less noted use of tubes is to allow you focus more closely with > telephotos, where the minimum focusing distance may not be close enough. > > I'd see buying a set of extension tubes as a good first step into macro / > close up photography. You can always use them later, even if you buy a > dedicated macro lens. But a _good_ macro is worlds better than a regular > lens on tubes, especially as you move away from the center of the image. I > have used an M 200 f4 on tubes, and an A* 200 f4 macro without tubes. Guess > what? The $1000 macro outperforms the $75 regular lens! Similarly, a $200 > 100mm macro will outperform a zoom or even a regular 100mm lens on tubes. > > If you have only zoom lenses, I'd recommend getting close up filters for > macro work - but there again, good ones are not cheap. > > HTH - > > - MCC > > - - - - - - - - - - - - - - - - - - - - > Mark Cassino Photography > Kalamazoo, MI > www.markcassino.com > - - - - - - - - - - - - - - - - - - - - > - Original Message - > From: "Village Idiot" <[EMAIL PROTECTED]> > To: > Sent: Tuesday, April 05, 2005 1:39 PM > Subject: Macro Extension Tubes > > > >I have questions about macro extension tubes. Does anyone use extension > >tubes? On what on what lenses do you usually use them? What is the > >difference between using extension tubes and using a macro lens? Also, why > >do extension tubes not work on DSLRs? > > > > I have always been curious about extension tubes and was thinking of > > purchasing some (maybe on eekbay). I thought I might try them out on > > flowers and bugs. > > > > Thanks in advance for your help, > > > > Derek > > > > > W
Re: Macro Extension Tubes
I use extension tubes all the time - a few basics: 1. A lens's focal length is that distance at which that lens will focus at infinity. Multiple element lenses complicate this a bit, but in the most simple terms a 100mm lens, for example, will focus at infinity 100mm from the film plane. That's why it is called a 100mm lens. :-) 2. As you move the lens further from this point, you move the plane of focus closer. A lot of lenses focus by just moving the a bit further out from the film. This moves the lens off infinity focus, and lets you focus closer. 3. The point at which the extension of the lens equals the lens's focal length results in a magnification of 1:1 - i.e. the image on the film is the same size as the object itself. So - with a theoretically simple 100mm, that is focused at infinity when it is 100mm from the film, if you add 100mm of extension, the lens will now focus very close, and the image on the film will be the same size as the object photographed. 4. When you focus closer, you magnify the image. Understanding the optical effects of magnification is they key to understanding macro and close up photography. Everything else is just derivative from the impact of magnification. 5. Every lens has aberrations and distortions. When you add extension and magnify the image, those aberrations and distortions are also magnified. In theory, macro lenses have been designed to overcome these problems. I have yet to see a situation where a non-macro lens matched a macro lens in performance at high magnification (greater than 1:1). That said, some lenses - like the Pentax 50mm f1.7 M, A, F, or FA, (all the same optical formula) do work very well with extension. 6. There's no problem using tubes with Digital SLRs. I use Vivitar tubes that have the full contacts, and with A or later lenses I loose only autofocus. I also use tubes and bellows for snowcrystal photos - lots of tubes. In that case I rely on the TTL flash to control the exposure. Pentax does not make tubes with contacts needed for auto exposure / aperture control, but third parties do. The thing with tubes - you can buy just plain tubes with no contacts and no mechanical connector to stop down the lens, you can get them with just the mechanical connectors to control the aperture but no electronic contacts, or you can get them with both mechanical and electronic contacts. The latter will result in an A or better lens working fine with a digital SLR, except that you will have to manually focus. 7. A less noted use of tubes is to allow you focus more closely with telephotos, where the minimum focusing distance may not be close enough. I'd see buying a set of extension tubes as a good first step into macro / close up photography. You can always use them later, even if you buy a dedicated macro lens. But a _good_ macro is worlds better than a regular lens on tubes, especially as you move away from the center of the image. I have used an M 200 f4 on tubes, and an A* 200 f4 macro without tubes. Guess what? The $1000 macro outperforms the $75 regular lens! Similarly, a $200 100mm macro will outperform a zoom or even a regular 100mm lens on tubes. If you have only zoom lenses, I'd recommend getting close up filters for macro work - but there again, good ones are not cheap. HTH - - MCC - - - - - - - - - - - - - - - - - - - - Mark Cassino Photography Kalamazoo, MI www.markcassino.com - - - - - - - - - - - - - - - - - - - - - Original Message - From: "Village Idiot" <[EMAIL PROTECTED]> To: Sent: Tuesday, April 05, 2005 1:39 PM Subject: Macro Extension Tubes I have questions about macro extension tubes. Does anyone use extension tubes? On what on what lenses do you usually use them? What is the difference between using extension tubes and using a macro lens? Also, why do extension tubes not work on DSLRs? I have always been curious about extension tubes and was thinking of purchasing some (maybe on eekbay). I thought I might try them out on flowers and bugs. Thanks in advance for your help, Derek
Re: Macro Extension Tubes
Joseph Tainter wrote on 4/5/2005, 3:22 PM: > "I have the Vivitar AF set which supports ALL functions necessary for > automatic aperture control and autofocus just like the "A" lenses." > > Christian, could you clarify which Vivitar set you have, and how one > finds them? The only Pentax AF extension tubes I am aware of are the > Kenko Teleplus extenders in 12 and 25 mm. lengths. I have to apologize for my treatment of photographic gear. I have no idea what model the vivitar tubes are... :-( All I know is that they have all the little contact thingies to support AF and metering. And, judging by the way these things are, I wouldn't be surprised if they were just re-branded Kenko tubes pr vice-versa... and looking at some eekbay stuff... the Kenko tubes do look just like my Vivitars. > Oh...weren't there some Vivitar tubes that also contained glass? Do you > have these? No. By definition, extension tubes should have no glass. There is a vivitar 2x Macro converter that is basically a helicoid extension tube grafted to a 2x TC. -- Christian [EMAIL PROTECTED]
RE: Macro Extension Tubes
Is this a case of "Pentax Stupid Model Number" confusion? VI: The *ist is a FILM camera. The *ist-D and *ist-DS are DSLRs. The DSLRs will use most any accessory ever made for Pentax cameras. The *ist uses very few, that's why I no longer own one. Don > -Original Message- > From: Graywolf [mailto:[EMAIL PROTECTED] > Sent: Tuesday, April 05, 2005 3:48 PM > To: pentax-discuss@pdml.net > Subject: Re: Macro Extension Tubes > > > The *ist has no manual mode. The ext tube have not program mode. > Hence incompatable. > > graywolf > http://www.graywolfphoto.com > "Idiot Proof" <==> "Expert Proof" > --- > > > Village Idiot wrote: > > Thanks for your help Godfrey. > > > > > >>What do you mean, "extension tubes not work on DSLRs"? Of course they > >>work on DSLRs. > > > > > > I miss read the Pentax Japan website. It actually reads "This > accessory is not compatible with the *ist". > > > > > http://www.pentax.co.jp/english/products/filmcamera/accessory/inde > x35_closeup.html > > > > Which begs the question, why are most tubes incompatible with the *ist? > > > > Thanks again for your help. > > > > Derek > > > > > > > > > >>On Apr 5, 2005, at 10:39 AM, Village Idiot wrote: > >> > >> > >>>I have questions about macro extension tubes. Does anyone use > >>>extension tubes? On what on what lenses do you usually use them? > >>>What is the difference between using extension tubes and using a macro > >>>lens? Also, why do extension tubes not work on DSLRs? > >> > >>I use them, usually with a 50-135mm lens. I have the Pentax Automatic > >>set, which supports the lens' autodiaphragm operation but does not > >>transfer "A" exposure settings nor support auto focus. It essentially > >>makes any A, F, FA, DA or D-FA lens into an M lens. This is not > >>particularly convenient if the lens you're using doesn't have an > >>aperture ring, but the lenses I use with mine all have aperture rings. > >> > >>Using an extension tube is virtually the same as using a macro lens, > >>except that the latter usually support A mode and auto focus with the > >>current series macro lenses like the FA and D-FA models. Of course, > >>with an extension tube, the distances you can focus too are limited by > >>the lens' focusing helicoid in conjunction with the amount of tube > >>extension you've fitted. Dedicated macro lenses usually run from > >>infinity to 1:2 or 1:1 magnification steplessly. > >> > >>What do you mean, "extension tubes not work on DSLRs"? Of course they > >>work on DSLRs. > >> > >> > >>>I have always been curious about extension tubes and was thinking of > >>>purchasing some (maybe on eekbay). I thought I might try them out on > >>>flowers and bugs. > >> > >>I obtained a brand new set from an Ebay vendor for $75 or so. > >> > >>Pick up a copy of John Shaw's "Close Ups in Nature" for a good > >>introduction to macro work before spending money on extension tubes or > >>any other gizmos. > >> > >>Godfrey > >> > > > > > > > > > > > -- > No virus found in this outgoing message. > Checked by AVG Anti-Virus. > Version: 7.0.308 / Virus Database: 266.9.3 - Release Date: 4/5/2005 >
Re: Macro Extension Tubes
The *ist has no manual mode. The ext tube have not program mode. Hence incompatable. graywolf http://www.graywolfphoto.com "Idiot Proof" <==> "Expert Proof" --- Village Idiot wrote: Thanks for your help Godfrey. What do you mean, "extension tubes not work on DSLRs"? Of course they work on DSLRs. I miss read the Pentax Japan website. It actually reads "This accessory is not compatible with the *ist". http://www.pentax.co.jp/english/products/filmcamera/accessory/index35_closeup.html Which begs the question, why are most tubes incompatible with the *ist? Thanks again for your help. Derek On Apr 5, 2005, at 10:39 AM, Village Idiot wrote: I have questions about macro extension tubes. Does anyone use extension tubes? On what on what lenses do you usually use them? What is the difference between using extension tubes and using a macro lens? Also, why do extension tubes not work on DSLRs? I use them, usually with a 50-135mm lens. I have the Pentax Automatic set, which supports the lens' autodiaphragm operation but does not transfer "A" exposure settings nor support auto focus. It essentially makes any A, F, FA, DA or D-FA lens into an M lens. This is not particularly convenient if the lens you're using doesn't have an aperture ring, but the lenses I use with mine all have aperture rings. Using an extension tube is virtually the same as using a macro lens, except that the latter usually support A mode and auto focus with the current series macro lenses like the FA and D-FA models. Of course, with an extension tube, the distances you can focus too are limited by the lens' focusing helicoid in conjunction with the amount of tube extension you've fitted. Dedicated macro lenses usually run from infinity to 1:2 or 1:1 magnification steplessly. What do you mean, "extension tubes not work on DSLRs"? Of course they work on DSLRs. I have always been curious about extension tubes and was thinking of purchasing some (maybe on eekbay). I thought I might try them out on flowers and bugs. I obtained a brand new set from an Ebay vendor for $75 or so. Pick up a copy of John Shaw's "Close Ups in Nature" for a good introduction to macro work before spending money on extension tubes or any other gizmos. Godfrey -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.9.3 - Release Date: 4/5/2005
Re: Macro Extension Tubes
I miss read the Pentax Japan website. It actually reads "This accessory is not compatible with the *ist". http://www.pentax.co.jp/english/products/filmcamera/accessory/ index35_closeup.html Which begs the question, why are most tubes incompatible with the *ist? Possible the *ist doesn't have the capability to meter correctly with them? I'm not familiar with that model Pentax. - Godfrey wrote: Possible the *ist doesn't have the capability to meter correctly with them? I'm not familiar with that model Pentax. - I think Godfrey got it right. The *ist, I believe, lacks the physical aperture simulator. The old ZX-50 was the same. You could use tubes on the *ist, but in manual mode, with metering supplied from some other source. You would need to focus wide open, then stop down to shoot. The D and DS have workarounds for this problem, but not the *ist. Joe
Re: Macro Extension Tubes
On Apr 5, 2005, at 12:34 PM, Village Idiot wrote: What do you mean, "extension tubes not work on DSLRs"? Of course they work on DSLRs. I miss read the Pentax Japan website. It actually reads "This accessory is not compatible with the *ist". http://www.pentax.co.jp/english/products/filmcamera/accessory/ index35_closeup.html Which begs the question, why are most tubes incompatible with the *ist? Possible the *ist doesn't have the capability to meter correctly with them? I'm not familiar with that model Pentax. Godfrey
RE: Macro Extension Tubes
Thanks for you insight Don Derek > Ooo, if JCO were here he'd tell you buddy! ;-) > > Seriously, I used tubes for a long time. > It was inexpensive, with some very good results. > Now that I have some true macro lenses I get some > outstanding results, rather than just very good. > Tubes are a great way to get into "the world of the tiny" > and they have the added benefit (unlike 2x converters) of > not adding any distortion of their own. > > Just be aware of 2 things: > 1. True macro lenses are designed for the purpose and will > generally yield superior results, hence their higher cost. > 2. You will lose some light when "going macro", this is > true of even dedicated macro lenses. > In other words an already slow f/4-5.6 lens can get pretty > dark when extended. Focus is critical at high magnification, > dark = difficult. > > My favorite lens to use with tubes was the M50/1.4, it > did a great job. > > Happy bug hunting! ;-) > > Don > > > -Original Message- > > From: Godfrey DiGiorgi [mailto:[EMAIL PROTECTED] > > Sent: Tuesday, April 05, 2005 12:58 PM > > To: pentax-discuss@pdml.net > > Subject: Re: Macro Extension Tubes > > > > > Using an extension tube is virtually the same as using a macro lens, > > > > Godfrey > > >
Re: Macro Extension Tubes
Thanks for replying Christian! Derek > > > Godfrey DiGiorgi wrote on 4/5/2005, 1:57 PM: > > > On Apr 5, 2005, at 10:39 AM, Village Idiot wrote: > > > > > I have questions about macro extension tubes. Does anyone use > > > extension tubes? On what on what lenses do you usually use them? > > > What is the difference between using extension tubes and using a macro > > > lens? Also, why do extension tubes not work on DSLRs? > > hmmm missed the original post > > Anyway, Macro lenses have built-in extension and focus from very close > to infinity. If you use extension tubes on any lens, you lose infinity > focus. > > The one good thing about tubes is that you really don't need to worry > about what brand you buy. Since there is no glass in them (they are > just hollow tubes) you don't need to worry about them affecting image > quality the same way a lens does (just make sure they are light-tight!). > > I use them a lot on my ist D. I have the Vivitar AF set which supports > ALL functions necessary for automatic aperture control and autofocus > just like the "A" lenses. I've used them on my 300/4 Sigma Macro to get > just a little closer. I've used them on a vivitar 105mm macro for more > than life-size images and I've used them with a 50mm both regular and > reverse mounted. > > -- > Christian > [EMAIL PROTECTED] >
Re: Macro Extension Tubes
Thanks for your help Godfrey. > What do you mean, "extension tubes not work on DSLRs"? Of course they > work on DSLRs. I miss read the Pentax Japan website. It actually reads "This accessory is not compatible with the *ist". http://www.pentax.co.jp/english/products/filmcamera/accessory/index35_closeup.html Which begs the question, why are most tubes incompatible with the *ist? Thanks again for your help. Derek > On Apr 5, 2005, at 10:39 AM, Village Idiot wrote: > > > I have questions about macro extension tubes. Does anyone use > > extension tubes? On what on what lenses do you usually use them? > > What is the difference between using extension tubes and using a macro > > lens? Also, why do extension tubes not work on DSLRs? > > I use them, usually with a 50-135mm lens. I have the Pentax Automatic > set, which supports the lens' autodiaphragm operation but does not > transfer "A" exposure settings nor support auto focus. It essentially > makes any A, F, FA, DA or D-FA lens into an M lens. This is not > particularly convenient if the lens you're using doesn't have an > aperture ring, but the lenses I use with mine all have aperture rings. > > Using an extension tube is virtually the same as using a macro lens, > except that the latter usually support A mode and auto focus with the > current series macro lenses like the FA and D-FA models. Of course, > with an extension tube, the distances you can focus too are limited by > the lens' focusing helicoid in conjunction with the amount of tube > extension you've fitted. Dedicated macro lenses usually run from > infinity to 1:2 or 1:1 magnification steplessly. > > What do you mean, "extension tubes not work on DSLRs"? Of course they > work on DSLRs. > > > I have always been curious about extension tubes and was thinking of > > purchasing some (maybe on eekbay). I thought I might try them out on > > flowers and bugs. > > I obtained a brand new set from an Ebay vendor for $75 or so. > > Pick up a copy of John Shaw's "Close Ups in Nature" for a good > introduction to macro work before spending money on extension tubes or > any other gizmos. > > Godfrey >
Re: Macro Extension Tubes
GD> On Apr 5, 2005, at 11:20 AM, Don Sanderson wrote: >> Ooo, if JCO were here he'd tell you buddy! ;-) GD> Who is "JCO" and why would I care what he'd have to tell me? For the same reason we could care what you have to tell us - we all are PDML members... GD> I've only been using extension tubes, bellows and macro lenses for GD> 40 years or so. Only that? Just another newbie... ;-) Good light! fra
Re: Macro Extension Tubes
"I have the Vivitar AF set which supports ALL functions necessary for automatic aperture control and autofocus just like the "A" lenses." Christian, could you clarify which Vivitar set you have, and how one finds them? The only Pentax AF extension tubes I am aware of are the Kenko Teleplus extenders in 12 and 25 mm. lengths. Oh...weren't there some Vivitar tubes that also contained glass? Do you have these? Thanks, Joe
Re: Macro Extension Tubes
C> The one good thing about tubes is that you really don't need to worry C> about what brand you buy. Since there is no glass in them (they are C> just hollow tubes) you don't need to worry about them affecting image C> quality the same way a lens does (just make sure they are light-tight!). Ah Christian now it is obvious that you have never tried Leitz extension tubes. The difference in quality of photographs is astounding!!! ;-) Good light! fra
Re: Macro Extension Tubes
On Apr 5, 2005, at 11:20 AM, Don Sanderson wrote: From: Godfrey DiGiorgi [mailto:[EMAIL PROTECTED] Using an extension tube is virtually the same as using a macro lens, Ooo, if JCO were here he'd tell you buddy! ;-) Who is "JCO" and why would I care what he'd have to tell me? I've only been using extension tubes, bellows and macro lenses for 40 years or so. Seriously, I used tubes for a long time. It was inexpensive, with some very good results. Now that I have some true macro lenses I get some outstanding results, rather than just very good. Presuming that you have equal quality lenses, there should be no difference in the quality of your results. Of course, as you point out below, true macro lenses are optimized for near-field focusing requirements and usually perform better. I often use an extension tube in conjunction with a macro or enlarging lens if my macro lens doesn't suit a particular purpose by itself. 1. True macro lenses are designed for the purpose and will generally yield superior results, hence their higher cost. 2. You will lose some light when "going macro", this is true of even dedicated macro lenses. In other words an already slow f/4-5.6 lens can get pretty dark when extended. Focus is critical at high magnification, dark = difficult. This is true of all lenses that focus by extending the objectives away from the imaging plane. Light falloff simply isn't significant until you reach a substantial extension. You usually need to stop down a lens quite a bit to gain enough DoF in macro work too. Settings of f/16-f/32 are common place, exacerbating the need for a steady camera support. My favorite lens to use with tubes was the M50/1.4, it did a great job. I've used both A50/1.4 and A50/1.7. They both do a good job, but the f/1.7 model has better flatness of field at close distances and is a superior macro performer. Godfrey
RE: Macro Extension Tubes
Ooo, if JCO were here he'd tell you buddy! ;-) Seriously, I used tubes for a long time. It was inexpensive, with some very good results. Now that I have some true macro lenses I get some outstanding results, rather than just very good. Tubes are a great way to get into "the world of the tiny" and they have the added benefit (unlike 2x converters) of not adding any distortion of their own. Just be aware of 2 things: 1. True macro lenses are designed for the purpose and will generally yield superior results, hence their higher cost. 2. You will lose some light when "going macro", this is true of even dedicated macro lenses. In other words an already slow f/4-5.6 lens can get pretty dark when extended. Focus is critical at high magnification, dark = difficult. My favorite lens to use with tubes was the M50/1.4, it did a great job. Happy bug hunting! ;-) Don > -Original Message- > From: Godfrey DiGiorgi [mailto:[EMAIL PROTECTED] > Sent: Tuesday, April 05, 2005 12:58 PM > To: pentax-discuss@pdml.net > Subject: Re: Macro Extension Tubes > > Using an extension tube is virtually the same as using a macro lens, > > Godfrey >
Re: Macro Extension Tubes
Godfrey DiGiorgi wrote on 4/5/2005, 1:57 PM: > On Apr 5, 2005, at 10:39 AM, Village Idiot wrote: > > > I have questions about macro extension tubes. Does anyone use > > extension tubes? On what on what lenses do you usually use them? > > What is the difference between using extension tubes and using a macro > > lens? Also, why do extension tubes not work on DSLRs? hmmm missed the original post Anyway, Macro lenses have built-in extension and focus from very close to infinity. If you use extension tubes on any lens, you lose infinity focus. The one good thing about tubes is that you really don't need to worry about what brand you buy. Since there is no glass in them (they are just hollow tubes) you don't need to worry about them affecting image quality the same way a lens does (just make sure they are light-tight!). I use them a lot on my ist D. I have the Vivitar AF set which supports ALL functions necessary for automatic aperture control and autofocus just like the "A" lenses. I've used them on my 300/4 Sigma Macro to get just a little closer. I've used them on a vivitar 105mm macro for more than life-size images and I've used them with a 50mm both regular and reverse mounted. -- Christian [EMAIL PROTECTED]
Re: Macro Extension Tubes
On Apr 5, 2005, at 10:39 AM, Village Idiot wrote: I have questions about macro extension tubes. Does anyone use extension tubes? On what on what lenses do you usually use them? What is the difference between using extension tubes and using a macro lens? Also, why do extension tubes not work on DSLRs? I use them, usually with a 50-135mm lens. I have the Pentax Automatic set, which supports the lens' autodiaphragm operation but does not transfer "A" exposure settings nor support auto focus. It essentially makes any A, F, FA, DA or D-FA lens into an M lens. This is not particularly convenient if the lens you're using doesn't have an aperture ring, but the lenses I use with mine all have aperture rings. Using an extension tube is virtually the same as using a macro lens, except that the latter usually support A mode and auto focus with the current series macro lenses like the FA and D-FA models. Of course, with an extension tube, the distances you can focus too are limited by the lens' focusing helicoid in conjunction with the amount of tube extension you've fitted. Dedicated macro lenses usually run from infinity to 1:2 or 1:1 magnification steplessly. What do you mean, "extension tubes not work on DSLRs"? Of course they work on DSLRs. I have always been curious about extension tubes and was thinking of purchasing some (maybe on eekbay). I thought I might try them out on flowers and bugs. I obtained a brand new set from an Ebay vendor for $75 or so. Pick up a copy of John Shaw's "Close Ups in Nature" for a good introduction to macro work before spending money on extension tubes or any other gizmos. Godfrey
