Hi, all,

I just picked up a Sony 2x TC to pair with my Canon 8-15.

Does anyone have 3D plans or a suggestion for a zoom gear?

Here is the exact housing setup:

Nauticam housing

Sony a1

Nauticam N100 to N120 35.5

Nauticam N120 30mm + 20mm Extensions

Nauticam 140 dome

Lens assembly order:

Body > Sony 2x TC > Metabones > Canon 8-15

The gear teeth would need to line up with the zoom knob on the N100 to N120 adapter.

I have the zoom gear for the 1.4x TC, but the Sony is a completely different size and in an entirely different position in the assembly.

Thanks!

chip

Hi Chip,

Are you sure the right extension for Canon+2xTC is 50mm?

I use it with 60mm extension (35mm&25mm) and Dreifish even suggested more, based on his testing (but I get occasional vignetting by sensor stabilization when I take his suggestion)...

In my files I see that for Canon+1.4x Kenko an extension of 50mm is required - your zoomgear should just fit in case you use the 50mm extension (maybe you have to remove the gear teeth wheel from the 35.5mm extension before it fits?).

I do not use a separate zoomgear, but use an extension collar for my regular Nauticam zoomgear (placed in the DIY section for 3D print). I remember faintly that someone (Gudge?) fabricated an entire zoomgear and placed it also there...

Wolfgang

Zoom gear designer mentioned here

Also its suggested that 30mm is enough extension same thread few replies in

5 hours ago, Architeuthis said:

Hi Chip,

Are you sure the right extension for Canon+2xTC is 50mm?

I use it with 60mm extension (35mm&25mm) and Dreifish even suggested more, based on his testing (but I get occasional vignetting by sensor stabilization when I take his suggestion)...

In my files I see that for Canon+1.4x Kenko an extension of 50mm is required - your zoomgear should just fit in case you use the 50mm extension (maybe you have to remove the gear teeth wheel from the 35.5mm extension before it fits?).

I do not use a separate zoomgear, but use an extension collar for my regular Nauticam zoomgear (placed in the DIY section for 3D print). I remember faintly that someone (Gudge?) fabricated an entire zoomgear and placed it also there...

Wolfgang

Hi, @Architeuthis - I saw the 60 total, but only have 50, so I gave it a try.

Even at the full wide end of 8mm, there is zero vignetting with the 140 dome with the shade attached. IQ looks good as well. The results will be from a dive.

Thanks, @Sokrates for the gear producer’s name. I’ll reach out to see what he has. I’ll also try the 30 extension to compare as well.

I did super basic tests with both the 8-15 + 2x and the WACP to compare.

Seems the 8-15 more or less matches the 130 FoV at ~10mm, followed by some similarities. The WACP with the 28-60 obviously has more reach with the 8-15 being a full 180 FoV.

In short, the 8-15 with both a 1.4x and now 2x gives wide flexibility, especially once a zoom gear is found. The 28-60 remains strong for medium wide to tight with near macro level close focus.

Between them, it should make for a very fulsome solution!

Edited Saturday at 11:00 PM1 day by ChipBPhoto

9 hours ago, ChipBPhoto said:

Hi, @Architeuthis - I saw the 60 total, but only have 50, so I gave it a try.

Even at the full wide end of 8mm, there is zero vignetting with the 140 dome with the shade attached. IQ looks good as well. The results will be from a dive.

Thanks, @Sokrates for the gear producer’s name. I’ll reach out to see what he has. I’ll also try the 30 extension to compare as well.

I did super basic tests with both the 8-15 + 2x and the WACP to compare.

Seems the 8-15 more or less matches the 130 FoV at ~10mm, followed by some similarities. The WACP with the 28-60 obviously has more reach with the 8-15 being a full 180 FoV.

In short, the 8-15 with both a 1.4x and now 2x gives wide flexibility, especially once a zoom gear is found. The 28-60 remains strong for medium wide to tight with near macro level close focus.

Between them, it should make for a very fulsome solution!

You would expect that with less extension you would not run into vignetting, what this does is move the centre of curvature back behind the entrance pupil of the lens, so it's no longer optimally placed. This will cause I believe a bit more barrel distortion and a slight loss of field of view.

Having said all that it seems Fisheye optics are less sensitive to the exact placement of the dome compared to rectilinear lenses in my view, though there are some who will argue this point. It's good to see the performance looked good when you tested it. It seems to be a great very flexible solution.

On Wolfwangs's point about zoom gears - I'm not sure I got the meaning exactly, however changing the extension tube in front of the N100-N120 adapter has no impact upon the the zoom gear fit. On the topic of zoom gears I used Wolfgang's adapter solution to get my zoom gear matching the knob in my N85-N120 adapter, but found it would lose mesh when turned unless i provided inward force on the knob. It prompted me to change over to a zoom gear that uses the housing zoom knob and I find that a lot easier to use.

UPDATE - I was able to remove the mount at the bottom of the Metabones. This allowed the N100 30 Extension to be mounted directly to the housing.

Setup in order of assembly:

NA-a1, N100 30 Extension, N100-N120 35.5 adapter, N120 20 Extension, Nauticam 140 dome

Sony a1, Sony 2x TC, Metabones V, Canon 8-15

Initial image quality looks good. No vignetting with the shade attached. The real test will be in the water soon.

BONUS: Based on the setup above, the Nauticam 815+TC Zoom Gear works perfectly!!

Collecting all the various bits over the years pays off. 😁

FURTHER UPDATE w/ 60mm: I also setup the following to allow a total of 60mm of extension (30+30):

NA-a1, N100 30 Extension, N100-N120 35.5 adapter, N120 30 Extension, 140 dome

RESULTS:

Shade is very prominent in image until ~12mm.

This leaves only 3mm of zoom, which is no zoom at all.

In short, the shade must be removed leaving the glass completely unprotected.

Image quality does not appear to be noticeably different.

Short answer, thank for the useful comments. Fortunately, I have an existing solution and do not need to "invest" any more than already made! WooHoo!!!!

Cheers!

chip

@Architeuthis @Sokrates @Chris Ross @Gudge

2 hours ago, ChipBPhoto said:

UPDATE - I was able to remove the mount at the bottom of the Metabones. This allowed the N100 30 Extension to be mounted directly to the housing.

BONUS: Based on the setup above, the Nauticam 815+TC Zoom Gear works perfectly!!

Collecting all the various bits over the years pays off. 😁

FURTHER UPDATE w/ 60mm: I also setup the following to allow a total of 60mm of extension (30+30):

NA-a1, N100 30 Extension, N100-N120 35.5 adapter, N120 30 Extension, 140 dome

RESULTS:

Shade is very prominent in image until ~12mm.

This leaves only 3mm of zoom, which is no zoom at all.

In short, the shade must be removed leaving the glass completely unprotected.

Image quality does not appear to be noticeably different.

Hi Chip,

by removing the mount, you mean the tripod mount attached to the Metabones?

Good information that a standard zoom gear works with this setup. Does that mesh with the adapter gear or the housing gear?

Not doubting what you observed at all, but it does seems odd that your setup vignettes at 60mm plus 35.5mm adapter but Wolfgang reports he uses 60mm total extension with the 35.5mm adapter, the fact some of the extension is on the other side of the adapter should make no difference.

@Chris Ross Here are the non-scientific, “try-it-and-see” results.

The housing was placed in the same position on all tests.

Details are on each image. Note “16mm” is 8mm plus the 2x TC.

There is also an image of the actual 50mm extension setup to validate.

The dome is the Nauticam 140 dome with the removable shade attached.

The zoom gear used is the Nauticam C815-Z+1.4

The knob on the N100-N120 35.5 adapter controls the zoom gear.

Note - the tripod mount on the Metabones V needed to be removed as it was blocked by the lock mechanism in the N100 30 Extension.

Remember, this was not intended to be a test of a compelling image or focus chart. It was simply to see what works and does not. I am not interested in math equations regarding perceived optimal lens placement. I just wanted to see the trial and error results.

Hopefully this is helpful info.

Edited 3 hours ago3 hr by ChipBPhoto

It looks to be a neat solution. I like the try-it-and-see approach for zoom fisheye lenses combined with teleconverters noting that if the fisheye lens can focus close enough to the dome then it is advantageous for CFWA to have the extension as short as possible irrespective of vignetting.