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The advantages of fisheye zooms!


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I recently acquired a Canon 8-15 fisheye.  Calculations show it covers the range from full frame fisheye to 28mm FF equivalent, albeit with barrel distortion the whole way - a pretty handy range.  To visualise this I took a series on indoor shots at medium (1.8m ) and CFWA distances with the 8-15 and a 7-14 rectlinear.  What we are covering here is reach - a rectilinear has quite different look to a fisheye as we will see and I'm not claiming the rectilinear and fisheye lenses are interchangeable for all subjects.

 

First up shots taken through a standard door (about 2.1m high) from a distance of 1.8m.

This is at 7mm/8mm, you can see the door is rendered about the same size even though the field of view in frame is much wider due to barrel distortion of the fisheye.

7-14vs8-15_wide.jpg

 

Next up zoomed in to 14/15mm.  You can see again the door frame is about same size in each shot - this time with similar angle of view.

7-14vs8-15_Zoomed_in.jpg

 

Next some CFWA style images with the bag about 220mm from the sensor at 8/7mm, You can see the bag is rendered larger although the field of view is much wider in the fisheye:

7-14vs8-15_wide_CFWA.jpg

 

Now with the lens zoomed in, this is about the close focus limit for the 7-14, the fisheye can go a lot closer though yielding  larger subject size.

7-14vs8-15_zoomed_CFWA.jpg

 

Again you see the subject rendered significantly larger with the fisheye and actually covers a smaller field - 110mm for the fisheye and 160mm for the rectilinear lens.

 

This means the 8-15 replaces my 8mm fisheye and my 7-14mm Panasonic lens.  The distant frames show what you might expect when for example trying to shoot sharks and other large animals where you can't quite get close enough with just the fisheye and the second set of images shows what you might achieve in CFWA shots and shows the advantage of using the fisheye.

 

The door shows how the barrel distortion is reduced middle of the frame but is makes the door look fatter - this is the fisheye effect which brings your chosen subject, be it a shark or sea fan forward in the frame and more prominent.  It looks like this will be a very flexible combination and means I can effectively travel with this setup and just the one lens and dome if I'm expecting to shoot large pelagics as well as reefscape shots and CFWA.   and perhaps just add a macro lens/port. 

 

I'm using this on m43 olympus and you can do similar with APS-C and Tokina 10-17, full frame however needs the new Fisheye Conversion port.

 

I picked up the lens and N85-120 adapter locally just need to find a 140mm dome and 35mm extension before my next trip.😃

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Thanks a lot Chris, this is really informative!  I’m a macro shooter on m4/3 but missed the boat for CFWA and have recently been thinking about getting into it.


What’s the total setup - lens plus adapter plus port plus extension?  Does that port have both a focus gear and a zoom gear?

 

Other than zoom and thus main subject image size, are there other advantages of this setup over the 8mm FE behind the 4.33 inch dome?

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6 hours ago, Troporobo said:

Thanks a lot Chris, this is really informative!  I’m a macro shooter on m4/3 but missed the boat for CFWA and have recently been thinking about getting into it.


What’s the total setup - lens plus adapter plus port plus extension?  Does that port have both a focus gear and a zoom gear?

 

Other than zoom and thus main subject image size, are there other advantages of this setup over the 8mm FE behind the 4.33 inch dome?

You need the N85-N120 34.7mm adapter then 35mm extension then 140mm port.  If you have the 4.33"port and it's an N120 already you can use that instead, believe the extension is the same.  You need a 3D printed part to adapt the Canon 8-15 zoom ring as the 34.7 adapter is designed to use with the Metabones speed booster which is 5mm thinner.  You use the focus knob on the adapter to zoom rather than the housing zoom knob, so you basically can't use both.

 

You can also use the Tokina 10-17 with the speed booster, all equipment is the same except I think it's the 30mm extension and you just use the zoom gear directly.  It's all in this thread:  https://wetpixel.com/forums/index.php?/topic/61629-canon-ef-lenses-on-mft-cameras/page/4/&tab=comments#comment-446983

 

I think the 8mm FE is pretty much equivalent to the 8-15 at 8mm, the advantage is the zoom giving you reach so you can shoot smaller CFWA subjects and shoot shy pelagics that don't come close enough.  Also means you can for example shoot a hawkfish sitting on a coral from a bit further back.  For me it means I can leave the dome for the 7-14 at home and just shoot with this combination. 

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1 hour ago, Interceptor121 said:

Well done Chris only 4-5 years late on this lol

 

https://interceptor121.com/2019/11/02/fisheye-zoom-for-micro-four-thirds/

 

credit to @Architeuthis for the original push 

Better late than never and with all the talk about the new FCP, this is basically the same thing but now available on full frame.  Yes Wolfgang did a lot of good work on this with m43!

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I think that the photo series by Chris shows much better the difference and similarity between rectilinear and fisheye than any comparison of angle of views, is it diagonal, horizontal or vertical can do...

 

I was using the Canon 8-15mm fisheye with 140mm dome for several years on EM5II and EM1II and can only second that this is an excellent and versatile combination for WA, CFWA and ultra-WA on MFT. Since I started to use it, I never again used the Oly 8mm fisheye and only very seldom the Pana 7-14mm behind a bigger dome...

 

My wife is still using the Tokina 10-17mm with Zen DP100 (N120 version without extension, with both 1x and 0.71x adapter) on EM1II. I think now that this is the ideal combination for MFT as this combination is even more compact (due to the 100mm dome; the Canon with 140 dome makes a rig the very similar size as now my FF rig is, when I use this lens...) and, depending on adapter used, covers two different, but overlapping focal length ranges (1x adapter, e.g., for shy sharks). I know that it is hard to believe that IQ with this lens, that performs miserably over the water, is UW, more or less, the same as with the Canon L series lens, but it is a fact, proven by many. Certainly the use of 0.71x speedbooster, that makes the image circle smaller, helps to improve IQ, but even with the 1x glassless adpater IQ is very good (maybe one should not use the Tokina with the 1.4x TC)...

 

Here is a table that shows the calculated diagonal angles of view of Panasonic, rectilinear, 7-14mm and the Canon 8-15mm, Tokina 10-17mm and Zuiko 8mm fisheyes in different configurations (1x glassless adapter, 0.71x speedbooster and 1.4x TC):

 

image.png

 

Value for Zuiko 8mm fisheye is from product specifications, while for Canon and Tokina fisheyes it was calculated according to equisolid fisheye. The difference between 170° and 180° is probably very small in practice...

 

Wolfgang

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Edited by Architeuthis
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Here is another table that shows the different extensions (in mm) that I have calculated, tested and proved in practice to work very well with different domes (Nauticam 140mm, Zen 170mm and Zen 100mm, all without buit-in extensions and N120 versions). NT: not tested; Green: calculated optimum extension and tested to work very well; Yellow: calculated optimum in parenthesis, but extension tested and works very well...

 

 

Picture 1.png

 

 

Wolfgang

Edited by Architeuthis
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