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05-22-2014, 03:39 PM   #16
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QuoteOriginally posted by Na Horuk Quote
lol not sure if you are joking
I was joking. I was tempted to do the same thing in my comment above linking to the same Web page.


Steve

05-22-2014, 03:43 PM   #17
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QuoteOriginally posted by Lowell Goudge Quote

Keep in mind that IF is achieved by reducing focal length as you focus..
Most modern macrolenses (like the F/FA 100mm macro) reduce the focal length when doing close focus, in combination with extension.
So most 100mm macro lenses are no 100mm lenses anymore at 1:1, unless you keep them at infinity, and put them on a 100mm extension tube.
05-22-2014, 03:45 PM   #18
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IIRC Canon's 100mm macros are IF...but that doesn't help you out much!
05-22-2014, 06:10 PM   #19
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QuoteOriginally posted by stevebrot Quote
It is a floating element design (common feature for macro lenses), but I don't believe that either Makro-Planar is internal focus. The product photos on photozone.de show the typical long extension for the 50/2.
correct the Zeiss 50mm f/2 and 100mm f/2 are both extension focusing, so does the Voigtlander 125mm f/2.5 APO SLII

QuoteOriginally posted by vonBaloney Quote
he Sigma 180/3.5 comes to mind, I think maybe one of the Sigma 105s also?
yes the Sigma 180mm f/3.5 and the current 180mm f/2.8 APO Macro lens both have internal focusing mechanisms. The Sigma 105mm f/2.8 doesn't have internal focus but the sigma 150mm f/2.8 does. The Pentax FA*200mm f/4 ED also has internal focusing.


Pentax K5IIs - Sigma 180mm f/3.5 APO EX


Last edited by Digitalis; 05-23-2014 at 04:01 AM.
05-22-2014, 06:20 PM   #20
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QuoteOriginally posted by Digitalis Quote
correct the Zeiss 50mm f/2 and 100mm f/2 are both extension focusing, so does the Voigtlander 125mm f/2.5 APO SLII



yes the Sigma 180mm f/3.5 and the current 180mm f/2.8 APO Macro lens both have internal focusing mechanisms. The Sigma 105mm f/2.8 doesn't have internal focus but the sigma 150mm f/2.8 does. The Pentax FA*200mm f/4 ED also is internally focusing.


Pentax K5IIs - Sigma 180mm f/3.5 APO EX
Yeah, looks like the Sigmas other than the older 180/3.5 that were IF were never available in Pentax mount. (The new 180/2.8 is not either as of yet.)
05-23-2014, 07:11 AM   #21
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Wow! Thanks for the replies!

I recently purchased a D FA 50mm macro for DSLR scanning of slides and general macro work. The lens produces wonderfully sharp images and I am impressed with its macro capabilities. However, the extending front element barrel feels very fragile. It looks like it can barely support the weight of the lens it is holding! You can even wobble the plastic extension a bit if you're gentle. Adding my slide/negative holder or even a hefty filter seems to stress the lens out. I wish the lens was a solid barrel filled with internally moving glass. For general macro work it would be nice to know that focusing will never cause me to bump into my subject. Remember, the D FA 50mm has a really, really short working distance. It doesn't bother me since I'm not shooting insects or other living organisms that may get startled.
05-23-2014, 08:16 PM   #22
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QuoteOriginally posted by 6BQ5 Quote
You can even wobble the plastic extension a bit if you're gentle.
I'll just add that my D FA 100mm WR does this too. Since I bought it used I was a bit concerned at first but after some searching around it seems like it may be normal, an intentional design decision that makes the focusing smoother or something.
05-24-2014, 12:45 PM   #23
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An earlier comment in this thread stated that Internal Focusing (IF) 1:1 macro lenses had shorter focal distance than
non-IF versions. This doesn't seem to be significant when I look at various macro lenses on the market. Canon's
100mm L series IF lens has a focal distance of 0.99ft compared to 1ft for the non-IF version. Other brand 100mm macro
lenses seem to have minimum FD of 1ft (or very near to) as well. Difference in effective focal length at full
magnification only differs slightly between the two Canon 100mm macros (78mm vs 75mm).

The more important factor in most close-up photography situations is the distance from front element to subject (Minimum Working Distance).
Since IF lenses don't increase in length, the lens to subject distance should be greater than a non-IF lens as long as the
IF lens is shorter than the fully extended non-IF lens. Comparisons I found for MWD did not show a clear advantage to
either IF or non-IF (ie it was lens-specific). The Sigma 105mm loses a full inch of MWD to both Canon 100mm lenses even
though it has greater focal distance.

One clear advantage of IF designs is that focusing doesn't create suction into the lens and should be a better design
for creating weather/dust proof lenses.

I know I would be happy if Pentax were to re-release the FA*200mm f4 IF macro in a weatherproof design! (Ricoh are you listening?)

05-27-2014, 11:47 AM   #24
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One advantage of the Canon 100mm L is having a silent motor.. The DFA 100 is a great lens, but it makes a lot of noise..
05-27-2014, 02:56 PM   #25
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QuoteOriginally posted by Serpiente Quote
The DFA 100 is a great lens, but it makes a lot of noise
if you focus manually that isn't a problem - which at 1:1 you will be doing anyway since AF, regardless of the camera being used isn't quite accurate enough for close macro work.
05-27-2014, 03:39 PM   #26
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QuoteOriginally posted by Digitalis Quote
if you focus manually that isn't a problem - which at 1:1 you will be doing anyway since AF, regardless of the camera being used isn't quite accurate enough for close macro work.
I don't do 'real-macro' so for me AF is the way to go. Most of my subjects are amphibians and reptiles. They have good ears.
I use MF when I can not lock on the subject in AF-mode.
05-27-2014, 04:03 PM - 1 Like   #27
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QuoteOriginally posted by Serpiente Quote
I don't do 'real-macro' so for me AF is the way to go. Most of my subjects are amphibians and reptiles. They have good ears.
It's hard to argue with that!
05-27-2014, 05:06 PM   #28
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QuoteOriginally posted by Lowell Goudge Quote
What you need to do is rethink just a little

A 100mm macro at 1:1 magnification is 200 mm away from the subject. You simply should not be that close!


You should practice moving back slightly as you focus, or better still set the lens to the magnification ratio you want, it will either be marked, or set the focus distance to give you the magnification ratio you want, then do the "coarse focus" by moving in towards the subject. Use the lens focusing collar for fine focus control
Or use a macro rail. There's usually an inexpensive Velbon multi-axis macro rail FS on eBay. The single axis Pentax Macro Focusing Rail is a tank - medical equipment quality - but is rare and very pricey.
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