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Architeuthis

Canon EF lenses on MFT cameras?

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Question re canon 8-15 with smart adapter. The lens is now 5mm longer so the glass is closer to the dome
Are there consequences on image quality? There is also a 35 extension ring in case this is not perfect?

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Posted (edited)
4 hours ago, Interceptor121 said:

Question re canon 8-15 with smart adapter. The lens is now 5mm longer so the glass is closer to the dome
Are there consequences on image quality? There is also a 35 extension ring in case this is not perfect?

Sent from my SM-A505FN using Tapatalk

Hi Interceptor,

I did not test the 1x Smart Adapter with the 30mm extension (I use it for the 0.71x speedbooster). I always use 35mm (1x Smart) and 55mm (1x Smart +1.4x Kenko; 35+20mm).

Here a listing of the extensions how I use them (they are probably appropriate - but i did not do any test series nor measurement of entrance pupil; I choose them after corresponding with and as suggested by Nauticam and Zen):

image.thumb.png.48c42bfd08c8101005201399783ac4b8.png

Wolfgang

Edited by Architeuthis

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Ok so you are effectively adding the 5mm required

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Am looking at your FOV table and am not sure how you tested that. 

The Tokina 10-17 with the speedbooster is 7.1 - 12.07 on the MFT body the Canon is 8 - 15 

The theoretical field of view calculations on an 8mm show less than 180 degrees however when you are looking at lenses you need to consider 22.5 mm as the diagonal which means at 8 mm you will get  fisheye anyway and the Tokina should vignette at wide end a little and at the same time because the crop with the speedbooster is 0.71 giving a total of 1.42 the lens will be wider than the nominal 100 degrees more 110 degrees.

At the same time the 8-15 should not go below 88 degrees with the smart adapter

I will run some comparisons with the panasonic 8mm fe

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Posted (edited)
26 minutes ago, Interceptor121 said:

Am looking at your FOV table and am not sure how you tested that.

=> I did not test, but calculate. There are several construction types for fisheye lenses available, and Canon and/or Tokina may not be strictly 100% one type. Formula for equisolid fisheye was taken (FOV (equisolid fisheye) = 4 * arcsin (frame size/(focal length * 4)); "framesize" is diagonal im mm, in case you want diagonal FOV). The differences between types are not hughe, so problem is a little bit academic. Results are very good to estimate what you will get...

 The Tokina 10-17 with the speedbooster is 7.1 - 12.07 on the MFT body the Canon is 8 - 15

=> Exactly. Tokina with booster gives vignetting @10mm (=7.1mm) and one need to zoom out a little to avoid. Canon @8mm with Smart 1x adapter is just perfect (with booster there is, of course, even more vignetting, so 0.71x is even less desireable).

The theoretical field of view calculations on an 8mm show less than 180 degrees however when you are looking at lenses you need to consider 22.5 mm as the diagonal which means at 8 mm you will get  fisheye anyway and the Tokina should vignette at wide end a little and at the same time because the crop with the speedbooster is 0.71 giving a total of 1.42 the lens will be wider than the nominal 100 degrees more 110 degrees.

=> The calculations for equisolid FE gives 170 degree FOV. Since there are different construction types and real lens may be a mixture, 8mm cam give 180 degree for another (as Zuiko or Pana 8mm)...

=> The difference between the (calculated) 170.2 of the Canon 1x @8mm and 180 degree is not so much in reality: note that the spacing of degrees on the diagonal is not uniform with fisheye and the increments become smaller and smaller the closer you come to the corner (this makes the "fisheye" look). I am even not so shure that the specifications of manufacturer are so accurate, when they say it is 180 degree: it could very well mean some degrees less (maybe also more), when precisely measured...

At the same time the 8-15 should not go below 88 degrees with the smart adapter

=> see here the table with exact values (also FOVs for rectilinear WA lens are given - they can be calculated very accurate, of course):

image.png.405a2427b7534392d0da3b1f434a3f4e.png

are

I will run some comparisons with the panasonic 8mm fe

I am really eager to hear what your practical experience will be (I am very fond of the Canon 8-15mm with 1x - it became my standard WA lens). AF performance will depend on camera body: with EM1II C-AF+tracking work very well, while with EM5II S-AF is o.k. ...

 

Wolfgang

Edited by Architeuthis

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I am very interested in the 8-15 with smart adapter as it fills a gap. Right now I have nothing between the 130 degrees of the WWL-1 and 180 degrees of the 8mm fisheye

I also want to see how it performs around 105 degrees and what is the level of distortion as I am hoping to take the 8-18mm out of the mix 

For autofocus I only use single AF with wide angle shooting f/8 mostly for macro AFF but otherwise even just centre on single AF

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Posted (edited)
2 hours ago, Interceptor121 said:

I also want to see how it performs around 105 degrees and what is the level of distortion as I am hoping to take the 8-18mm out of the mix

The level of fisheye distortion becomes reduced as the FOV is reduced upon zooming in. My guess is that the WWL-1 (and also the WACP) have similar amount of fisheye distortion when compared to "zoomed out" fisheye lens at comparable FOVs

Sharpness of Canon 8-15mm @15mm on MFT is superb as @ 8mm and with every fisheye (is'nt the Zuiko (or Pana) 8mm providing superb optical quality :)?). The trick how WWL1 and WACP manage to get such IQ might well be that they produce zoomed-in fisheye optics together with the standard zoom lenses.

I did, however, never use WWL-1 nor WACP, so I cannot say for shure. Really interested to hear from someone who uses both WWl1 and Canon 8-15mm on MFT and can compare in practice...

Wolfgang

Edited by Architeuthis

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The level of fisheye distortion becomes reduced as the FOV is reduced upon zooming in. My guess is that the WWL-1 (and also the WACP) have similar amount of fisheye distortion when compared to "zoomed out" fisheye lens at comparable FOVs (the trick how WWL1 and WACP manage to get such superb IQ might well be that they produce zoomed-in fisheye optics together with the standard zoom lens). I did, however, never use WWL-1 or WACP, so I cannot say for shure. Really interested to hear from someone who uses both WWl1 and Canon 8-15mm on MFT and can say from practice...
Wolfgang
I did extensive tests on wwl-1 and you are correct it has the same behaviour of fisheye around 10.6 mm but the missing 2.5 to 8 are very important!

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@Architeuthis one other consideration you want to make on the fisheye lenses in general is that although the specifications for field of view are given on the diagonal this is not really what matters to us. We are interested in the horizontal and vertical field of view.

When I compared the WWL-1 with the 7-14 I found out that while on the diagonal there is a difference on the horizontal the lenses behave similarly and on the vertical the 7-14 is actually wider. This is an outcome of the fisheye distortion that pulls the diagonal and then compacts it back in the frame in a barrel shape. In my tests the fisheye distortion on the wwl-1 is present until 2.5x zoom on the 14-42 and is less apparent in video just because the 16:9 crop is not affected by the vertical compression so the image is more straight

So in in reality 15 on the canon zoom on mft body with 1x converter is not the same as 12 mm rectilinear but is like a 13 on the horizontal and 14 on the vertical if it makes sense.

The teleconverter on the 1x for me makes very little sense as I am under what I would call true wide angle (90 degrees on horizontal corresponding to 8 linear)

When I look at the tokina on MFT body with speedbooster ultra this does not make too much sense as due to the crop factor being 1.42x and not 1.5 or 1.6 the lens remain too wide when fully zoomed

So the way I see it is that for what I need (once I decide to spend a fortune in lens ports adapters and glass)

Canon 8-15 (fundamentally from fisheye to 13.5 mm) 1x or corresponding to kenko + metabones on the nauticam chart

Leica 12-60 rectilinear (this is mostly for portrait work of mid size fish)

Olympus 60 mm macro

I am hoping to cover every wide angle situation with the 8-15 including split shots and wrecks, split will need a large acrylic dome to float

I will keep you posted as I go along...

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@Architeuthis

First tests with tripod confirm what I thought on the horizontal a 12mm rectilinear is the same as the 8-15 at 14mm zoom 

Image quality is pretty much the same at the same aperture, the Canon 8-15 exhibits fringing while the panasonic does not but this is because the camera corrects it for all panasonic lenses. The purple fringing is only visible in corner at 1:1 pixel ratio and once you click remove chromatic aberrations in Lightroom it goes away without any loss of sharpness it is really tiny

Field of view I have not been able to do scientific test the canon is much longer lens and the additional lenght means the Panasonic is closer to the target of around 3 inches therefore the frame looks bigger however I am extrapolating that once the front are at the same distance it will be identical more or less

One consideration is obviously as this is DSLR size the dome is much bigger and so is the port compared to the Nauticam acrylic 4.33 or even smaller 3.5". If you are into wide angle macro this lens is not really the best combination and better rely on the panasonic for that.

Will report on the port system once it arrives...

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I deposited some sample images for the Canon 8-15mm, 1x adapter and EM1II that I took during last week's exciting workshop at the Red Sea:

 

Wolfgang

 

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