UW Wideangle to Macro Lens Swapping

[Alex B]

Thanks Barmaglot. I will have to measure my threading depth on the housing port and protrusion of the rear element on my wide lens but I'm not sure I understand your calculations and what my tolerance should be as doesn't it also depend on the depth of the connecting rings and the distance between the port glass and the inside edge of the port thread? If I give you my measurements for all those maybe you can work out with the set you have if it will fit? That would be really helpful. Sorry for all the back and forth!

On the actual fitting, do you have to attach the male and female parts by screwing in new attachment rings or does everything just thread into the existing threads? How difficult was it to work out from the instructions?

Cheers,
Alex

 

[Alex B]

Hi Barmaglot.

So here’s measurements from my Ikelite housing and Inon UWL-H100 28M67 Type 1 wideangle :

Port glass to inside edge of port thread 1mm
Port thread 5mm
Lens thread 3mm
Lens rear element protrusion past thread 1mm
Port glass to wide angle lens rear element 2mm (from above figures, if i’m correct?)

How does that compare to your measurements without the NiteScuba magnetic system?
Do you think it will work on mine from comparing these measurements?

 

[Barmaglot]

Are you sure it's only protruding 1mm past the threads? Looking at the photos on Inon's website, it's the type 2 that sits almost flush with the threads, while type 1 protrudes a significant amount. I'm talking about this portion:

On my WFL05S, this is what it looks like:

There is 5mm of threading, and then it narrows and protrudes another 7mm past that. When the two magnetic rings are joined, and the lens is screwed into the male part, that rear element ends up flush with the threads, which are themselves 3mm high, like this:

If there is only 3mm of threading on your lens, and 5mm of threading on your port, then the magnetic adapter should be able to accommodate up to 11mm of protrusion past the threads - 2mm inside the 'male' adapter ring, another 7mm inside the 'female' adapter ring, and another 2mm inside the port. Anything less than 11mm will leave empty space between lens rear element and port glass.

 

[Alex B]

Thanks Barmaglot. I was told I needed the Type I Inon UWL-H100 28M67 wideangle with protruding rear element for my Ikelite housing and that is what is on my invoice so I don't know why mine only has 1mm protrusion beyond the 3mm thread and looks different from your photo. Maybe they gave me the wrong lens? Or would the rear element of the H100 Type in your photo maybe protrude more than the 2mm gap between the port glass and rear element that I must currently have? What is the gap between the port glass and your rear element or is it zero?

On the measurements of your lens and mine then it seems I would have 2mm less than yours inside the male adaptor and 6mm less inside the female, with 1mm between port glass and inside edge of port thread and 2mm between inside edge of port thread and inside edge of female adaptor, if I got that right? That would mean 11mm empty space between port glass and my wideangle rear element, which sounds like it would result in a lot of vignetting, especially on a wideangle when you won't be zoomed in to the max like a macro lens.

Why is there a thread though anyway on the male adaptor and female adaptor if this is a magnetic system? How can it work magnetically if there are male and female threads?

 

[Barmaglot]

See here on Inon's website, there are photos of both type 1 and type 2: INON Wide Conversion Lens UWL-H100 28M67 [Overview] - which one matches the lens that you have? It is possible that they've sent you a type 2 by mistake, while invoicing the type 1 - you might be able to exchange the lens to the proper model, or get a replacement ring (this part is removable and interchangeable).
10-11mm of empty space between port glass and lens rear element would almost certainly introduce significant vignetting, but it should be considerably less with the proper part.
There are no threads between the adapter rings, but there is a male thread on the 'female' ring that screws into the port, and female thread on the 'male' ring that the lens screws into.

 

[Alex B]

Thanks Barmaglot. I think they must have shipped me the wrong lens! Problem is I only now discovered that and I have already dived with the lens last Dec after it was shipped in Nov! I did notice a bit more vignetting than expected at the recommended 28mm but didn't think it was significant so didn't check measurements but now it will be for this adaptor mount system which adds further distance from the port glass.

To give me a better idea of how this system would work on my equipment, can you let me know what is the gap between your port glass and your rear element with and without the system please?

On the system adaptor rings, I understand there is a thread to attach each ring to the lens and port but it looks from your last photo that there is also a thread on the male adaptor attaching to the lens that protrudes 3mm?

What is the total additional distance that the system adds between lens and port?

 

[Barmaglot]

The threads visible in my last photo are the threads that go into the port. The visible glass is the rear element of the lens.

The adapter adds 7mm of thickness, provided both threaded parts match their counterparts exactly. Please excuse my paint skills, this is the basic idea of the cross-section of the system:

At the bottom you have the port, with 5mm of threading. The female ring threads into it, with its 3mm of threads, leaving a 2mm space. Red blocks are the magnets that hold the two rings together, and on top of the female ring is the male ring, with 5mm of threading. The total distance between the point where male ring threading ends and the female ring threading ends is 7mm. My WFL05S has 5mm of threading and 7mm of protrusion, and it ends up sitting flush with the adapter threads, and 2mm away from the port glass. Since Inon UWL-H100 only has 3mm of threading, it will not go as deep into the male ring, and it will have an additional 2mm of clearance. Therefore, to reach the port glass with its rear element, it needs 2+7+2=11mm of protrusion.

You should be able to convert your type 2 into type 1 with the proper swap kit such as this: INON M67 Screw Ring Set for UWL-H100 28M67 Type1 but I have no idea how much protrusion it provides - maybe someone who actually owns one of these lenses can chime in here.

 

[Alex B]

Many thanks Barmaglot. That is super helpful.

So what I'm looking at in your last photo is the whole male+female assembly+lens, not just the male adaptor attached to the lens?

The distance between port glass and rear element if I was to use this magnetic system with my housing and lens then is basically 2+7+2 less whatever the protrusion on my rear element is (which is currently 1mm but only because I have the Type 2 instead of the Type 1 H100 which I should have had for my Ikelite housing. From the Inon link you sent earlier showing the difference in protrusion between Type 1 and Type 2, it looks like the Type 1 should be similar but maybe not quite as much as your lens and as the lens thread is 2mm shorter than yours, I will have more headroom anyway.

So with the Type 1 port glass to rear element I will have 2+7+2 less 1mm protrusion = 10mm vs your 2mm
With the Type 2 port glass to rear element I will have 2+7+2 less say 5mm protrusion (I will get precise measurement from Inon next week) = 6mm vs your 2mm, which is much better than Type 1 on vignetting issue.

Does that all sound correct?

 

[Barmaglot]

So what I'm looking at in your last photo is the whole male+female assembly+lens, not just the male adaptor attached to the lens?

Correct.

With the Type 2 port glass to rear element I will have 2+7+2 less say 5mm protrusion (I will get precise measurement from Inon next week) = 6mm vs your 2mm, which is much better than Type 1 on vignetting issue.

Sounds about right. I don't know how much vignetting you'll have as I have no experience with your camera model, but I've seen several posts, here and elsewhere, complaining about excessive vignetting with Panasonic LX10 and wet lenses, using combinations that, reportedly, work fine on other cameras, so I suspect that LX10's lens is especially susceptible to these issues,

 

[Alex B]

Nothing I can do about that now as already have the system (chosen over Sony and Canon 1" on Backscatter review). All i can do is make sure as possible what the degrees of compatibility are likely to be with new equipment, which you have been super awesome in helping with! I have now notified my wideangle lens supplier that they shipped me the wrong lens and they've offered to send a replacement and refund me the shipping cost of the wrong one. They did however ask me if it had been used, which I did not reply. It has been used on about 3 dives. As it was their error supplying the wrong lens type, that shouldn't make a difference to their liability especially for that amount of use don't you think?