Isaac Szabo

Oh no, sorry Alex! I hope it doesn't put too much of a damper on your trip. Maybe I should look into tethering the lens to the port?

Thanks Tim!

Thanks Brandon. It's hitting me pretty hard at the moment, but I'm sure I'll get past it pretty soon.

Thanks for the kind words about my freshwater work, Brandon! Sounds good. Hopefully a few more pop up soon. The turnaround time has varied quite a bit depending on how many other lenses I have in at the moment and whether or not things have been going smoothly. Sometimes it has been as short as a week or two, other times well over a month. Currently I am running behind as a number of things have conspired against me (lots of orders, difficulty getting good optical alignment on one lens and having to redo it a few times, my 3D printer breaking and needing parts/repairs, my basement flooding, and just today getting covid for the first time and feeling horrible). But once I get caught up again my goal is to be getting them done within around a week (or two at the most).

I haven't tried hand polishing with cerium oxide, but I do think it could work. Also, it may be obvious, but I should note that polishing with cerium oxide can remove optical coatings from glass. I'm not sure if your viewfinder is coated and if so whether removing the coating would cause any issues. The front dome of the RS 13mm is coated, but I have not been able to detect any issues from removing it.

I use a benchtop buffing machine with cerium oxide powder mixed in water on the buffing wheel. It removes water stains from glass very effectively. It can remove scratches from glass as well, though it does so very slowly. Since I'm doing it manually it is only practical for removing light scuffs and scratches - deeper ones would take too long. Care must be taken to not let the glass heat up too much during polishing, which means polishing passes of 5-10 seconds followed by immersion in cool water for at least the same amount of time before continuing polishing again. At some point in the future I hope to figure out an automated system so I can leave it running for hours/days and remove deep scratches. Back when I used acrylic domes I removed scratches from them with the benchtop buffer with a plastic polishing compound on the buffing wheel. It worked very well and didn't take too long. It was much easier than polishing by hand and gave me much better results. Again it was important to keep the dome moving so no particular area heated up too much and to take periodic breaks to let it cool down.

I'll mention that there is one on eBay for $2800 plus shipping/taxes. The front dome appears to have lots of water stains, and the seller says it also has a small/minor scratch. However, if you are planning to have me convert the lens to Sony, it's worth noting that I do have the ability to polish the front dome for an extra fee of $100. It would definitely remove all of the water stains, and it can also remove very light scratches and somewhat diminish deeper scratches. If you or anyone else is interested in maybe purchasing that copy, I would recommend messaging the seller and asking if they might accept less given the condition issues. Considering that other lenses without the condition issues have sold in recent months for prices similar to what they're asking, I personally would think somewhere around $2300-2500 would be more reasonable. And it has been listed for quite a while, so maybe they'd be motivated to accept a lower price.

Hi @Fabian! The vast majority of my photography is done in small to medium North American streams. While great clarity is nice, 1.5-2m is totally doable. You don't need great visibility as long as you can get your lens close to your subjects, so close focus wide angle and macro can work well. We are fortunate to have high freshwater biodiversity here in the US, but I'm sure there are some very interesting things to shoot in German streams too. If you're interested, my instagram is @isaacszabo.

Maybe you're already aware of this, but I'll mention that there are four on eBay right now. One in particular is interesting because it is an auction style listing starting at $2400 USD and ending in a little over a day. I'm not sure if anyone else will bid or if there is a reserve on the auction, but that price would be a good deal these days since the going rate seems to be $3000+.

Isotta is 38mm (for Sony mirrorless at least). Someone with a depth gauge measured N120 Nikon Z for me at 66mm. Is your 58.8mm measurement with a DSLR or mirrorless housing?

I assumed it would be the same until someone said it wasn't, which makes no sense to me for reasons you mention and others. Yep, for accuracy you need something that can span the port mount opening like this: Or as you mention you can lay a straight object across it and subtract its thickness:

Interesting. How accurate do you think your method was (ruler, calipers, depth gauge, etc)? It would be nice to know for sure since I make N100 RS13 ports. It's unfortunate that it's not the same for all their Sony FF housings. On this thread he claimed 27mm:

On my NA-A7II housing the distance is 26mm. Someone claimed it's 27mm on newer housings, though I haven't been able to confirm that yet.

Thanks! Maybe I'll try it if I get an SLA printer. The material properties relevant to my main application (making ports) look to be inferior to PETG (assuming I'm interpreting them correctly) at a cost 5-6X higher, so I don't think it would be a good option to replace what I'm already using for that. However, it may be useful some of my other applications that don't need as much strength and would benefit from increased detail.

That's great to hear. Glad it worked for you.

Can you recommend any affordable resins or additives to try for printing ports that might stand up to diving pressure, saltwater, UV, bumping into rocks, etc?

Nice. Of course it can work. I just said that it's not ideal when precision is needed since adding epoxy resin is imprecise. I used to add epoxy resin to o-ring grooves. It worked but sometimes I added a bit too much or not quite enough. I also personally just prefer to have prints waterproof straight off the printer and not have to put more work into them. But by all means do what works for you.

The profile I've developed in PrusaSlicer for my MK3 is not directly applicable to a different slicer/printer. However, the main settings that come to mind are: PETG filament 0.4mm nozzle 0.10mm layer height for ports, solid prints composed entirely of perimeters/walls for hollow items like a float, designs probably need a minimum wall thickness of around 3mm random outside seams and staggered inner seams extrusion multiplier/flow ratio around 20% higher than normal And then there are other tweaks to temperature, speed, linear advance, etc to improve print quality. Bambu's slicer is simpler than Prusa's and may not have all the necessary options (such as staggered inner seams), so using another slicer such as OrcaSlicer may be preferable. No matter what it will likely take a fair amount of experimentation to find a sweet spot between watertightness and acceptable print quality. You also need ways to test if the prints are actually waterproof and capable of withstanding pressure. I print a small test chamber that I can pull a vacuum on and monitor a pressure gauge to see if it holds a vacuum indefinitely or if leaks over time. If my print settings pass a vacuum test and I print a real object such as a port then in addition to a vacuum test I also I test it in a hydrostatic pressure chamber to ensure that the design will withstand the pressure that I need it to. Of course, if post processing prints with resin is working for you and you're happy with that, then there's no reason you need to do anything differently. I can see how that could work well for something like a float, but it's not ideal for something that requires more precision such as a port with an o-ring groove.

Like Dave said, for FDM it’s hard to beat Bambu Lab’s printers right now. They have a range of options, starting with the very capable A1 at only $340 (or $490 with the optional multi color/material unit). That said, if you happen to see a good deal on a used Prusa MK3 or MK3S, that’s the printer that I have developed a waterproof print profile for and could probably share it. The Bambu Lab printers are certainly newer/nicer, but you might have to do quite a bit of experimenting to find good waterproof settings. I have a Bambu Lab A1 too but haven’t developed a waterproof profile for it yet. I’d personally recommend skipping PLA and going straight to PETG for functional parts. PLA has a lower softening temperature (parts may soften/warp in a hot car for example), is not as durable in the elements, and is more brittle. PETG has been just as easy to print for me, and it’s just as cheap, so I see no reason to use PLA. Yes, SLS printers are still well beyond the range of hobbyists as far as I’m aware. However, you can always get your designs printed by print companies that have expensive SLS printers. Lucky you to have access to a CNC! It’s certainly possible. I print fully waterproof ports and other parts that require no post processing. I’ve been using them for 3-4 years. So far I have tested the ports to over 100m/330ft.

First a disclaimer: While I have some knowledge on resin printing, I don't actually have any experience using it yet (though I've been considering buying one). I believe resin prints are inherently watertight, unlike FDM prints, so that's a plus. They're also better at reproducing fine details. However, resin materials are generally weaker and more brittle than FDM materials, and I'm guessing they're more susceptible to degrading under harsh outdoor conditions. Also, resin printing seems to have more annoyances/frustrations due to the mess of the resins (which are health hazards), the washing/curing steps, etc. My experience is that most people choose FDM for functional prints. Resin printers seem to be more popular for things like miniatures where fine details are more important than strength/durability. That said, just as there are numerous types of FDM materials with different properties, there are many different types of resins, some of which are "tough" resins that are designed to have more strength/durability for functional parts. My impression is that they still lag behind the best FDM materials, but that doesn't necessarily mean they're not good enough for our purposes. To sum up, waterproofing is the challenge with FDM, though some people have been able to figure that out. On the other hand, strength/durability is the challenge with resin, and I'm less sure if that can be figured out for underwater parts that need to withstand high pressure, saltwater, sunlight, etc.

Actually, I think this version has a better chance of working. Maybe a moderator can remove the other file? N100 rear cap.stl

I think this should work. It works on my 3D printed N100 ports. I don't have an actual Nauticam port to try it on. Maybe get one printed first, and if it works well order more.

Unfortunately, I don't think there's an ideal mid/short macro for Sony yet. All the options have some limitations. If you have a port for the Sony 90mm, then I'd think the Canon 60mm with adapter should fit in that (that combo is a little smaller than the 90mm). The Canon 60mm has some vignetting on full frame at medium and far distances but not at close distance. I'm not sure that its AF will be an improvement over the 90mm, but it's pretty fast in good light using the central focus points. Another option is adapting the Nikon 60mm. From what I've heard it doesn't work quite as well on the adapter as the Canon, but it is a full frame lens with no vignetting. The Sony 50mm is reported to be slower focusing than the other options. I'm curious how much vignetting the Zeiss 50mm has on full frame, but I haven't been able to find an account of someone trying that.

@Gerald Rambert If you set your camera to f/2.8 and look into the lens front the front, can you tell if the aperture is opening up all the way? Or if you dismount the lens and manually move the rear aperture lever while watching the aperture through the back of the lens, does the aperture appear to open up all the way? Does the aperture lever move freely/easily and spring back closed when you release it? Does it appear bent or damaged?

It's good to be aware of that, but it doesn't help explain exposure differences between different copies set to the same aperture.