10mm Laowa full frame lens.

[DreiFish]

On 7/18/2024 at 8:49 PM, DreiFish said:

 

Could be, I was just guestimating based on my recollection of what the 180mm dome looks like (mine is sitting packed in a closet) and the 10-15mm shorter extension Nauticam recommends in its port chart when using the 180mm dome instead of the 140mm or 230mm domes which don't have any protrusion at the back. In any event, the 180mm dome is definitely not anywhere near a full hemisphere like the 140mm or 230mm domes.

 

 

I took the Nauticam 180mm dome out of the closet. Turns out 10mm extension is way off.. it's hard to measure exactly with the calipers, but it looks like the conical extension on the back of the 180mm dome is more like 35mm from the back of the glass element. Nauticam lists this as being cut from a full sphere with a 110mm diameter,  and the distance from the front of the glass to the back of the conical extension is closer to 80-85mm, which would indeed place the center of curvature about 25-30mm behind the back flange of the 180mm dome.

 

Interesting... I need to redo my tests with the Canon 14-35 at the calculated extension of about ~60mm. Though I already know it vignettes with a 50mm extension because of the dome shade and the inside of the of the port itself. Nauticam recommends a 40mm extension with this combination, which theoretically places the lens entry pupil about 20mm forward of where it should be. But that may be the necessary compromise to avoid vignetting. 

 

[ScubaBC]

I received my Laowa 10mm yesterday, so I spent a few hours and designed and 3D printed a manual focus ring to work with my Aquatica housing and it's working perfectly.  Hopefully I'll get to give it a try today or tomorrow!

Edited July 30 by ScubaBC

[Davide DB]

Could you share the files and details in the DIY forum?

 

Thank you in advance

[Phil Rudin]

On 7/18/2024 at 8:49 PM, DreiFish said:

 

Could be, I was just guestimating based on my recollection of what the 180mm dome looks like (mine is sitting packed in a closet) and the 10-15mm shorter extension Nauticam recommends in its port chart when using the 180mm dome instead of the 140mm or 230mm domes which don't have any protrusion at the back. In any event, the 180mm dome is definitely not anywhere near a full hemisphere like the 140mm or 230mm domes.

 

 

The pictures Phil posted look promising in terms of the 20-70s performance with the 140mm dome. Sounds like a potent travel combination together with the Laowa 10mm.

 

  

 

 

 

 

Based on this, I would guestimate the Aquatica lens-mount to front of housing 'flange' distance to be around 40mm too. Below chart may be useful when converting port extensions from one housing manufacturer to another.

 

 

 

So probably the extension needed for Aquatica is similar to Marelux -- i.e. 20 to 25mm. At least I'd take that as a starting point for fine-tuning.

 

 

N100 + 35.5mm port adapter should produce the same flange distance as the n120 housings with no adapter, or at least within 1-2mm. This combination only vignettes slightly with the 140mm Nauticam dome at the top and bottom because of the dome hood, which is designed to accommodate a fisheye lens's more limited vertical field of view. Without the dome shade, there's no vignetting. With the dome shade on the left, no dome shade on the right. Both with Nauticam R5C (n120) housing and no extension.

 

 

 

 

 

Something seems strange about this Phil. The Nauticam N100 equivalent to a 35mm extension on Marelux (i.e. total extension from lens flange of 40mm + 35mm = 75mm) would be 75mm - 26mm (Nauticam n120 flange distance) = ~50mm of total extension. That would be the 35.5mm n100 to n120 adapter + a 15mm extension ring. I've tried the a similar combination on Nauticam N120 (a 20mm adapter) and you get heavy vignetting. I doubt that vignetting would disappear by moving the lens closer only 5mm.. I suspect you need more than that. So it's interesting that there's no vignetting with your set-up on Marelux. Perhaps the Marelux lens mount to front of housing flange distance is closer to 30mm than the 40mm we've been estimating? Could you measure this?

 

So my math is not that great but using your chart of  58.8cm for R5C with no adapter and 27mm for A7R V plus 35.5 adapter you get a total of 62.5 or a 3.7mm difference if I am understanding correctly. 

 

I don't own any precision tool but when I use a ruler the distance from the lens mounting ring to the top of the Marelux housing where the port seats against the front of the housing is close to 30mm +/-1mm. So Sony A7RV/A1 30mm + 35mm of extension for the 140mm dome port is 65mm. So the N100 to N120 35.5+15mm equals 50.5 plus 27 for Sony RV equals 77.5mm. So neither the 15 or 10mm extensions will work well. To get to 65mm for the Nauticam 140mm port it would be the 27mm for A7R V + 38mm of extension. So it seems that 35.5mm N100 to N120 would be as close as you can get. 

 

Also the 35mm distance is the same for both my Sony A7R V and A1 housings so no variations between housings. Also the Marelux 140mm port with bayonet shade sits flat against the port extension. I don't remember if Nauticam has  the same design so any differences would need to be taken into considerations.

 

I will test again using 30mm's of extension rather than 35mm and see if I find any improvement.

 

Also if someone has a more precise measurement for Marelux Sony housings please post.  

Edited July 30 by Phil Rudin

[Phil Rudin]

3 hours ago, ScubaBC said:

I received my Laowa 10mm yesterday, so I spent a few hours and designed and 3D printed a manual focus ring to work with my Aquatica housing and it's working perfectly.  Hopefully I'll get to give it a try today or tomorrow!

 

Hi BC, are you using the auto focus version or the Manual focus version?

[ScubaBC]

40 minutes ago, Phil Rudin said:

 

Hi BC, are you using the auto focus version or the Manual focus version?

I have the Sony auto focus version but I can still toggle manual focus through the camera and then use the focus wheel when I want to manually focus.

[dentrock]

6 hours ago, Phil Rudin said:

I don't own any precision tool but when I use a ruler the distance from the lens mounting ring to the top of the Marelux housing where the port seats against the front of the housing is close to 30mm +/-1mm. So Sony A7RV/A1 30mm + 35mm of extension for the 140mm dome port is 65mm. So the N100 to N120 35.5+15mm equals 50.5 plus 27 for Sony RV equals 77.5mm. So neither the 15 or 10mm extensions will work well. To get to 65mm for the Nauticam 140mm port it would be the 27mm for A7R V + 38mm of extension. So it seems that 35.5mm N100 to N120 would be as close as you can get.

Phil, in earlier posts this distance (lens flange to port flange for your Marelux) has been quoted as 43mm. If it is in fact approx. 30mm, that is good news and makes perfect sense. It also means that whatever best extensions you come up with for your Sony FF Marelux rig, we can apply to Sony FF Nauticam rigs, as the measured lens flange to port flange distance for the latter(26-28 depending on who measured and which model) is close enough to the Marelux figure. No need to add that 15-17mm extra for Sony / Nauticam, as quoted earlier in this thread.

 

Perhaps the 43mm is for sensor to housing flange?

 

The only remaining variable is where the optical centre lies for the Marelux 140 dome. I'm making the (bold) assumption that this is also close enough to the Nauticam 140 figure (6-7mm behind the dome port flange) as to not make any further difference, for the purposes of calculating necessary extensions.

 

I am keen to see how you go with reducing your extension from 35 to 30. Perhaps we can get to a compromise where corners are sharp enough with a shorter-than-theoretically-ideal extension -  and we don't need to remove the 140 port shade!

 

Apologies for all this measurebating, but I can't dive my Laowa 10 until next week at the earliest. Still, we have a great starting point!

[Phil Rudin]

So this is the Laowa 10mm with Marelux Sony A1 housing, 140mm dome port and 30mm extension. These were shot using the S&S conversion lens. My copy is the same 77mm as the lens soI thought I would give it a try. All were at F13 and the split is at F/22. First image is with the shade installed and you can Clearly see the shade at the top and bottom. Marelux shade is bayonet mount so it can be removed and reinstalled very quickly.

 

These were shot with the standard Marelux flash trigger using Apollo III strobes for fill at 1/400th sec.

 

You may also notice that the steps and tile are every bit as wide as the many shots I have posted with a verity of wet lenses with the same 130 degree AOV at 28mm and the same distance to subject. In fact they look wider than some wet 130 degree lenses I have tested. 

 

Edited July 31 by Phil Rudin

[DreiFish]

12 minutes ago, Phil Rudin said:

So this is the Laowa 10mm with Marelux Sony A1 housing, 140mm dome port and 30mm extension. These were shot using the S&S conversion lens. My copy is the same 77mm as the lens soI thought I would give it a try. All were at F13 and the split is at F/22. First image is with the shade installed and you can Clearly see the shade at the top and bottom. Marelux shade is bayonet mount so it can be removed and reinstalled very quickly.

 

These were shot with the standard Marelux flash trigger using Apollo III strobes for fill at 1/400th sec.

 

 

Hi Phil, 

 

Lens hood occlusion looks very similar to what I got with the Nauticam R5C housing with no extension (~58.8mm lens mount to front of housing distance) and 140mm dome. So I guess we can conclude that (a) Marelux distance from camera lens mount to front of housing is indeed around 30mm (not the 43mm earlier reported) and that (b) Nauticam 140mm dome and Marelux 140mm are probably very similar if not identical. 

12 minutes ago, Phil Rudin said:

 

 

 

 

Phil, was there any noticable improvement from using the Sea & Sea conversion lens?

[Phil Rudin]

5 minutes ago, DreiFish said:

 

Hi Phil, 

 

Lens hood occlusion looks very similar to what I got with the Nauticam R5C housing with no extension (~58.8mm lens mount to front of housing distance) and 140mm dome. So I guess we can conclude that (a) Marelux distance from camera lens mount to front of housing is indeed around 30mm (not the 43mm earlier reported) and that (b) Nauticam 140mm dome and Marelux 140mm are probably very similar if not identical. 

Phil, was there any noticable improvement from using the Sea & Sea conversion lens?

It appears the S&S may help but I need to look at more images at different F/numbers. Also the 30mm extension without the S&S. I first tried a 20mm extension when I got the lens and they were bad but also shot at F/8. I really need to start all over and evaluate any gain with S&S. 

[ScubaBC]

I went for a dive this evening using the Laowa 10mm.  I was using my 8" Aquatica Acrylic dome port and a 29mm extension (#48453) from the mini-macro port.  I left the dome shades ON. I definitely need to put some black tape over the letters as they were reflecting into the footage.  I am pretty impressed with this lens! There are certainly some soft corners and a slight bit of distortion on the outer edges, but I love the wide angle!  

The autofocus works quite well but it needs a lot of light, when we got deeper I really had to crank the ISO.  I pretty much shot F8 to F11 the entire time and the ISO ranged from as low as 640 to as high as 64,000 for some shots.  I try and stay 3200 or 12800 if possible as it seems to be the cleanest.  The A7Siii does handle high ISO pretty well.

Edited August 1 by ScubaBC

[ScubaBC]

I just got back from a trip to Barkley Sound, Vancouver Island with Rendezvous Dive Adventures and used the Laowa 10mm again.  Blake at Aquatica was kind enough to ship me their prototype dome port for this specific lens, so I gave it a try too.

This is a very challenging lens to use without excellent ambient lighting.  With very poor viz in the first 30 feet it made for some really dark diving, which makes the ultra-wide angle even more challenging.  I am using two Kraken 18,000 lumen lights, it's tough to avoid backscatter, even with the lights angled way out because of the ultrawide angle of the lens.  With good ambient lighting though, this lens is pretty cool to use!