Hi Boris -
How close up do you plan to get?
I think a macro lens is the best way to go overall for magnifications up to 1:1 (image size on the film/sensor is the same as in real life.) A 100mm macro is probably the sweet spot between price and working distance. 200mm's are probably the best all round macro option - but a whole order of magnitude more in price. For me, 50mm macros are too short to be useful, though I do use one for snow crystals.
I don't think AF is that important with macro work - you really have to think through were to put the plane of focus to maximize the very little DOF you have at high magnifications. Of course, if AF lets you use the macro for other purposes, that could be handy.
For going beyond 1:1 with a macro lens, or to just improve close focusing with a conventional lens, I lean towards extension tubes. I've always figured that not adding more glass elements minimizes the distortion. Many lenses just use extension to focus more closely, and tubes obviously just add extension. Magnification is generally the amount of extension divided by the focal length of the lens. So a 100mm lens on 100mm of tubes will give you 1:1 magnification. I say 'generally because a lot of lens utilize either internal focusing, or floating elements, which effectively change their focal length as you focus closer.
In regards to teleconverters - my experience has also been that teleconverters and lenses can come together in unpredictable ways - so until you try a particular TC with a particular lens, you won't know how well they will work. You are basically combining two sets of optics to form a single lens, and hoping that the combined lens will work. Sometimes it does, other times not. I've had some TC's that worked very well with some lenses, but not others.
Closeup diopters / close up filters / close up lenses, are another option. The image quality with single element close up lenses is not great, but the two element lenses can be excellent. I use a Canon 500D with my 6x7 and the quality is great.
You can also get rings that allow you to reverse mount one lens on another, also known as using 'stacked lenses'. With this technique the reverse mounted lens acts as a close-up diopter on the main lens. The magnification is the same as the main lens's focal length divided by the reverse mounted lens's focal length. So, if you reverse mount a 50mm lens on a 200mm, you are at 4x lifesized (200/50). It's a good way to get to high magnifications, but not handy for more typical close up work.
Lastly - just reverse mounting a lens offers some magnification, and greater correction when used on extension. I use a reverse mounted 50mm on bellows for snow crystals - but it is a pretty awkward setup for most applications.
Like I said - for general close up work, I'd lean towards a good 100mm-ish macro lens. If you want to same some money, and already have a good 100 or so prime lens on hand, getting a set of extension tubes or a good close up lens would be the second choice. Actually, the close up lens could be used on a zoom as well - so if you have a good zoom, that might be an approach to consider.
HTH -
MCC
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Mark Cassino Photography
Kalamazoo, MI
www.markcassino.com
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----- Original Message ----- From: "Boris Liberman" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, March 08, 2005 2:24 PM
Subject: Thinking of Macro
Hi!
Now that I have a proper tripod the macro ideas pop in my mind :).
On Friday I will be announcing for sale my Vivitar 2x Macro Focusing TC. I simply find that I don't use it at all, so I'd better let someone else use it.
It will keep me with Soligor Macro Converter which I probably will also sell and set of Pentax K extension tubes that offer no automation whatsoever, not even aperture lever.
Although among the options that I have, I think that extension tubes are best solution from quality point of view.
Now the question. What would you recommend to me as a possible way of doing Macro... I've been eyeing some macro lenses on eekBay but I am not sure I want to shell out the money. I've seen some AF extension tubes that I may want to buy... I've seen the reversing rings, but I've no clue as to how it us to use one.
Without offense or possible disrespect to others, I'd like those of you who do shoot macro often give me your opinions...
For now, I am going to attach my M 50/1.4 to the tubes and make it kinda macro-only lens. I don't have much use for this lens anyway, as I use my FA 50/1.7 on *istD.
Thanks for your time, I'm in rather talkative mood today.
-- Boris
