TAKO. INTERNET SEIT 1996.
Olympus-OM

Re: [OM] Son of Big Foot to ship in August

Subject: Re: [OM] Son of Big Foot to ship in August
From: Wayne Shumaker <om3ti@xxxxxxxx>
Date: Tue, 01 Sep 2020 11:13:01 -0700
At 6/27/2018 04:49 PM, Tempted Mike wrote:
>http://www.fredmiranda.com/forum/ufiles/86/1605286.jpg
>
>It is available for pre-order
>
>Looks very nice but not in OM mount like the 125. It is said to have 3 
>floating elements.  
>
>I suspect the new 110 may outperform Big Foot (CV125/2.5).  I have the 125 in 
>OM mount of course. I was curious as to the design as both have 58mm filter 
>size. A little digging revealed CV 125 has 11 lenses in 9 groups and the 110mm 
>14 lenses in 12 groups. There is clearly a large amount of FL shortening to 
>achieve 1:1 mag in the CV 125 as it loses much less light than my Z 135 
>bellows lens of almost same focal length. This is also revealed by the working 
>distance. Using thin lens approximation to obtain an idea of "effective focal 
>length " at 1:1
> ("EFL"= MFD/(2+m+1/m) or MFD/4 at 1:1.
> This is 95mm for the CV125 and 87.5 for the new 110. (MFD listed as 380mm for 
> CV125mm and 350mm for the 110)
>
> Oh, another perhaps major difference for hand held shots is the new 100 will 
> almost undoubtedly have a "focus distance encoder" like the 65 despite being 
> MF--this should enable 5 axis image stabilization (vs 3 axis on OM AR4x)  
> unlike any situation with the 125 (except tripod use of course). It does not 
> seem likely any of the AF adapters for MF lenses will even allow for manual 
> input of focus distance to enable x/y plan IS.  Techartpro was thinking about 
> it, but too much work for their one engineer apparently. 
>
>Tempted, Mike

Son of Big Foot arrived on my doorstep: Voigtlander 110mm f2.5 APO Lanther 
macro. I've been meaning to send this email for a while, hoping I would have 
some decent images to share. I'm still working on that. Some initial samples 
below.

Mike posted the above on 6/27/2018 and I have not seen any more posts about 
this 110mm lens on this list.

I decided to splurge and take advantage of the $100 off for this lens at BH. 
Its not an OM mount lens like the original Big Foot Mike has. This is a tank of 
a lens, with 470 degrees of focus throw. It is very smooth focus and allows for 
very precise focus when using the manual mode magnify feature in the camera. 
Extending the lens adds more weight to the lens compared to internal focus.

Initial use indicate this is sharp wide open (f2.5), and possibly the sharpest 
lens I have ever worked with.

The Big Foot 125 CV Mike has is now a collector's item. Used prices are around 
double the original price. The 110mm is an even better lens by most 
comparisons, and new is ~1/2 what people are asking for the original CV 125.

Interesting that the 110 comes with two lens caps. The lens hood screws on to 
the lens 58mm thread, and allows filters to be attached at the front of the 
lens hood with a 67mm thread. First time I have seen that kind of feature, but 
makes working with polarizer easier as you can mount one on the front of the 
hood. Comes with one 58mm lens cap and one 67mm lens cap for the front of the 
lens hood.

The (approximate) working distance at 1:1 is ~5.5 inches (14cm). This I 
measured from the lens hood since I almost always use a lens hood. The Sony 
90mm by comparison is ~3.25 inches (8.5cm) from the lens hood. The sony 90 has 
internal focusing? The 110 does not and extends way out. The Canon 180mm (also 
internal focus) macro working distance is ~8 inches (20.5cm), again internal 
focus and measured from the lens hood. One issue I now recall with the Canyon 
180mm was that manual focus was poor. Focus by moving is often the method of 
choice with that lens, or autofocus if it hits right.

Comparison at 1:1 minimum focus distance, effective focal length and working 
distance:
90mm MFD 280mm -> 70mm effective FL (change 0.777x)  WD 85mm
110mm MFD 350mm -> 87.5mm effective FL (change 0.795x) WD 140mm
180mm MFD 480mm -> 120mm effective FL (change 0.667x) WD 205mm

Some other differences. The 90mm sonie you can switch between manual and 
autofocus with the focus ring,  pushing or pulling. However, you can't 
autofocus and then switch to manual with the focus ring and preserve the focus 
point. The 90mm focus ring has a fixed scale, so when it switches, it goes to 
where the scale points. Only if you switch the camera to MF does it preserve 
the AF focus point. (which I have assigned to a button).

The Canyon 180mm, I now have, works well with Metabones adapter on Sonie (MC-11 
does not work). With that lens you can seamless AF and adjust manually. The 
disadvantage of the 180mm is focus throw is about 200 degrees compared to 470 
with the 110 and not very smooth - and it has some stiction when trying to make 
minor tweaks. The 90mm has less, about 180 degrees, but is very smooth.

Some initial images.

180mm at f3.5 (full res so can zoom in)
https://photos.app.goo.gl/MqkPtC5RZhbeWJst8

110mm at f5 (full res) focused on the nose
https://photos.app.goo.gl/WvgeKB8ibNjL2w6c7

110mm at f8 - zoom in for more detail. (I was limited by my neighbors wall)
https://photos.app.goo.gl/gKZduHZoD1WVkAYx6

110mm at 1:1
https://photos.app.goo.gl/5x1MzNFj2DxtPNPf9
This is an invasive species called globe chamomile (stinknet). I have resisted 
photographing until now as I despise this weed so much. In the spring is really 
smells. When it drys it becomes a fire hazzard.

I hope to get some more interesting photos. All three lenses are good lenses. I 
am mostly limited by DOF and camera shake. All three work with camera IBIS. The 
90mm also has OSS.

This 110mm manual focus lens is not for everyone. The working distance over the 
90 is very noticeable. I almost wish it had a tripod collar.

Aside: I improved the 180mm stiction with a 4" Band Joes on the focus ring 
overlapping the body to provide a bit more friction in the focus. I used this 
same trick with a Sonie 100-400mm on the Zoom ring to give it more friction and 
prevent zoom creep. Although it has a smooth/tight adjustment, tight is not 
enough to prevent zoom creep when pointed down while carrying it.

WayneS
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