Findings with using the TTArtisans 100mm F2.8 underwater

[Robin.snapshots]

During my diving trip last Christmas I got the chance to experiment a bit with getting the TTArtisans 100mm soap bubble lens to work on my sony underwater setup. 
I am not yet on a setup I am fully happy with but I will share my findings so far:

 

The lens installed on a m42-E mount adapter fits well and has full focus range in the nauticam 105 N100 port meant for the sony 90mm macro. There is a few millimetres space left when fully extended which could fit an ND filter. 

 

In the basic setup the focus range is too far out to be practical so I tried adding some macro tubes in-between the m42 adapter and the camera. About 20mm extension gives me a nice working distance on land but unfortunately I do not own the port extension to fit this combination so I have not tested this underwater.

It does fit inside the 105 port with 10mm extension  but can not fully extend. I tried this setup with a fixed focus by installing the lens in the housing as far out as it will go within the space and focussing underwater by moving the camera in and out. This worked (focus peaking is a lifesaver) but the working distance is still a bit too far for my liking. 

 

Next I 3d printed and hacked together a focus ring to be able to focus underwater and used that setup without any extension inside the port to have full focus range available and not smash the lens against the glass underwater. In order to get the magnification I wanted, I tried adding my SMC-1 which worked well for super macro but was a bit too strong for normal macro. I believe this setup with a weaker diopter could work quite well. 

 

What I learned the hard way was that a focus ring for an m42 lens also doubles as a lens remover quite well.  To tackle this I intend to purchase a m42 to E mount helicoid adapter which then also doubles as the macro extension. This also moves the part the focus ring has to grab onto further back, which makes the focus ring more stable as it can be shorter. I am also hoping another adapter will fix some of the internal reflections my current m42 adapter is giving me.

 

 

The lens itself is very similar to the trioplan 100, with much of the same nice bokeh but also the same problems. Consider it a much cheaper trioplan 100 without dust in it. 

[Buddha]

this is great. lkeep us posted. I want to try this also on my Sony.

[Silvana]

Thanks for sharing this! Gathering the pieces to use it with Nikon D850...

[Dave_Hicks]

That is great. A dive buddy started using yhe 56mm version of this lens and i was able to print a focus ring for it as well. 

[Silvana]

On 3/19/2024 at 8:13 PM, Dave_Hicks said:

That is great. A dive buddy started using yhe 56mm version of this lens and i was able to print a focus ring for it as well. 

Question please: how do you figure out how to 3D print a focus ring? I have a friend with a printer who will be willing to print things for me, but I don't know what to ask him. I do know what a focus ring is, but is it by trial and error to find the match for the lens and housing? Thanks!

[Dave_Hicks]

You need some experience with CAD software and lots of measurements. I designed and printed a replica of a gear i already had before I made a unique one. The gear part is always the same but the other dimensions will vary from lens to lens. Look at some other designs online (here for example) and work from there.

[Barmaglot]

12 hours ago, Silvana said:

Question please: how do you figure out how to 3D print a focus ring? I have a friend with a printer who will be willing to print things for me, but I don't know what to ask him. I do know what a focus ring is, but is it by trial and error to find the match for the lens and housing? Thanks!

I just made a zoom gear for Tokina 10-17mm fisheye to use with my SeaFrogs a6700 housing, and here's the process that I used. It might look primitive for someone with working knowledge of CAD, but it's what I came up with having had zero experience beforehand.

 

I used the free online TinkerCAD - it runs in a browser, so you don't need to install any software.

 

First, I took a pair of calipers and measured an existing zoom gear for my housing, finding the diameter at the tips of the teeth, at the bases of the teeth, and the width of each tooth. I also counted the teeth, ending up at 72 - a very convenient number, giving me exactly 5 degrees offset between each tooth.

 

Now, in TinkerCAD, I created a cylinder and set its diameter (width x length; TinkerCAD doesn't do 'diameter') to what I measured at the base of the teeth, and its height to the teeth's thickness. Then I added a box, with its length set to the gear's diameter at the tips of the teeth, width set to a tooth's width at the base, and height set to the same as the cylinder. I selected the box and the cylinder and aligned them to each other, so they would be centered. To this, I added four small boxes of the type 'hole' rather than 'solid', each rotated 30 degrees and positioned to intersect with the first long box at its junction with the cylinder. This is basically what I got:

 

 

Selecting the four small 'hole' boxes and the long red 'solid' box, I grouped them, and got my first two gear teeth:

 

null

 

Selecting this shape, I hit 'Duplicate and repeat (Ctrl+D)' and rotated the duplicated shape by 5 degrees:

 

 

Repeat 34 more times and I have a full gear of teeth. It's a bit tedious, but not that difficult:

 

 

Select all, group, and now I have my basic gear as a single piece.

 

Now, put the camera with the lens that I'm making this for into the housing, and use the calipers to measure the distance between the driving cog in the housing and the far edge of the zoom (or focus, if that's the target) ring on the lens - this is going to be the gear's height. Add a solid cylinder of the appropriate height, and diameter to fit within your port's internal diameter, with a few mm of clearance to spare. Add a hole cylinder slightly taller than everything and a few mm smaller in diameter than the solid one - the difference will be gear walls' thickness. Align everything:

 

null

 

Select all, group, and now the gear is hollowed out. Now, the final measurements are the width of the lenses zoom or focus ring, and its diameter. Add a solid box that is slightly longer than the hole cylinder I used to hollow out the gear in previous step, as tall as the target ring is wide, and a couple mm thick, pull it level with the top of the cylinder and align it in horizontal plane:

 

 

Duplicate, rotate 45 degrees, repeat two more times. Add a hole cylinder of the diameter equal to the target ring's diameter, drag it to overlap the four boxes, then align everything again:

 

null

 

Select all, group, and voila - the design is ready to send off to the printers. Export to STL and get in touch with your nearest printing service.

 

 

Now, in my case, I had to iterate once - the gear ended up being slightly too small; the teeth were barely catching on the driving cog. I just took the whole thing and increased width and length by 2mm - this got it perfect on the second print. The eight nubs that contact the lens also ended up slightly too long - they wouldn't fit over the lens, even after I expanded that last hole cylinder on the second print. Rather than do a third print, I simply filed them down a little bit, and now they fit perfectly.

 

I went through this whole process start to finish to take the screenshots to illustrate the post, using arbitrary values for sizing, and it took me maybe 30-40 minutes start to finish. Doing the actual measurements would add a little time, but still - this is basically an hour or so long project, not accounting for iterations.

[TimG]

Brilliant! What did it cost to print?

[Barmaglot]

I used a local shop here in Bangkok, and it cost me 650 THB (about US$18) to print zoom gear + the port adapter I'm working on, and another iteration of the port adapter that I just ordered cost me 350 THB (including shipping), so it's comfortably under $10.

 

For the reference, here's the fit of the gear inside the housing:

 

 

The contact pads are a bit untidy after I filed them down, but they work. The driving cog is on the bottom left, the other two are just frewheeling supports. 

Edited March 24 by Barmaglot

[Barmaglot]

Sorry about cluttering up the thread with only tangentially relevant info - @TimG, maybe it should be split into a separate thread in the DIY forum?

[Silvana]

On 3/23/2024 at 8:10 PM, Barmaglot said:

I just made a zoom gear for Tokina 10-17mm fisheye to use with my SeaFrogs a6700 housing, and here's the process that I used. It might look primitive for someone with working knowledge of CAD, but it's what I came up with having had zero experience beforehand.

 

I used the free online TinkerCAD - it runs in a browser, so you don't need to install any software.

 

First, I took a pair of calipers and measured an existing zoom gear for my housing, finding the diameter at the tips of the teeth, at the bases of the teeth, and the width of each tooth. I also counted the teeth, ending up at 72 - a very convenient number, giving me exactly 5 degrees offset between each tooth.

 

Now, in TinkerCAD, I created a cylinder and set its diameter (width x length; TinkerCAD doesn't do 'diameter') to what I measured at the base of the teeth, and its height to the teeth's thickness. Then I added a box, with its length set to the gear's diameter at the tips of the teeth, width set to a tooth's width at the base, and height set to the same as the cylinder. I selected the box and the cylinder and aligned them to each other, so they would be centered. To this, I added four small boxes of the type 'hole' rather than 'solid', each rotated 30 degrees and positioned to intersect with the first long box at its junction with the cylinder. This is basically what I got:

 

 

Selecting the four small 'hole' boxes and the long red 'solid' box, I grouped them, and got my first two gear teeth:

 

null

 

Selecting this shape, I hit 'Duplicate and repeat (Ctrl+D)' and rotated the duplicated shape by 5 degrees:

 

 

Repeat 34 more times and I have a full gear of teeth. It's a bit tedious, but not that difficult:

 

 

Select all, group, and now I have my basic gear as a single piece.

 

Now, put the camera with the lens that I'm making this for into the housing, and use the calipers to measure the distance between the driving cog in the housing and the far edge of the zoom (or focus, if that's the target) ring on the lens - this is going to be the gear's height. Add a solid cylinder of the appropriate height, and diameter to fit within your port's internal diameter, with a few mm of clearance to spare. Add a hole cylinder slightly taller than everything and a few mm smaller in diameter than the solid one - the difference will be gear walls' thickness. Align everything:

 

null

 

Select all, group, and now the gear is hollowed out. Now, the final measurements are the width of the lenses zoom or focus ring, and its diameter. Add a solid box that is slightly longer than the hole cylinder I used to hollow out the gear in previous step, as tall as the target ring is wide, and a couple mm thick, pull it level with the top of the cylinder and align it in horizontal plane:

 

 

Duplicate, rotate 45 degrees, repeat two more times. Add a hole cylinder of the diameter equal to the target ring's diameter, drag it to overlap the four boxes, then align everything again:

 

null

 

Select all, group, and voila - the design is ready to send off to the printers. Export to STL and get in touch with your nearest printing service.

 

 

Now, in my case, I had to iterate once - the gear ended up being slightly too small; the teeth were barely catching on the driving cog. I just took the whole thing and increased width and length by 2mm - this got it perfect on the second print. The eight nubs that contact the lens also ended up slightly too long - they wouldn't fit over the lens, even after I expanded that last hole cylinder on the second print. Rather than do a third print, I simply filed them down a little bit, and now they fit perfectly.

 

I went through this whole process start to finish to take the screenshots to illustrate the post, using arbitrary values for sizing, and it took me maybe 30-40 minutes start to finish. Doing the actual measurements would add a little time, but still - this is basically an hour or so long project, not accounting for iterations.

This is amazing, thank you so much for taking the time to explain! I will follow into your steps!

[Tobyone]

I use FreeCad to design my gears. It has a gear evoluter action. You just plug in MOD,# of teeth. and it sketches a gear.

One has to play with the perimeters to get thew gear to perfection.

Edited March 26 by Tobyone
could say it better.

[Jon Anderson]

I have also been playing with the TTArtisans 100mm Bubble Bokeh lens a little bit over the last 6 months and dove with it a few times in Monterey.  Hoping to shoot it more soon!  Like any manual focus lens its definitely a bit challenging to shoot underwater but has nice bokeh if your up for a challenge. It sounds like focusing is much easier on these lenses with mirrorless bodies with good focus peaking.
 

Here is my setup right now:
- Fotodiox M42 to F-mount adapter (non-optical, ~2mm flange to flange)

- Fotodiox F-mount extension tubes (14mm tube + adapters, actually measures 30mm flange to flange)
- Custom 3d printed focus gear that I designed

I used it on my D850 in Nauticam housing with the same Macro 60 port + 30mm extension ring that I use with my Nikon 105mm macro lens.  At full lens extension (closest focus) there is just barely a gap between the port glass and the front of the lens but it doesn't seem to touch. With this setup golf ball sized subjects fill the frame and at minimum focus the distance between the lens and the subject is about 10.5 in (270 mm)

Here is an uncropped example image from the setup described above. Shot at f/2.8, 1/250 sec, ISO 64
https://www.jonandersonphoto.com/California/Central-California/i-jnjrNt2/A

 

This is another image where I used a Kraken +6 diopter in front of the setup described above and cropped slightly. Shot at f/2.8, 1/250 sec, ISO 31 
https://www.jonandersonphoto.com/California/Central-California/i-pq7tFdS/A

I am thinking about revising my setup to use the more common Kenko extension tubes.  I effectively have 32mm of extension ring with the adapter,  I think others I typically use less extension ring but hard to say without knowing the thickness of their M42 adapter.  Also likely will try to use a ND 0.6 (2 stop) filter in the future to have a bit more exposure headroom.

I hope to share more on my website once I have time to get it organized.

 

Edited April 7 by Jon Anderson
adding photo

[Davide DB]

@Jon Anderson beautiful photos indeed. Congratulations!

 

Guys please share share share your proven 3D projects 😉

[Silvana]

On 4/6/2024 at 5:20 PM, Jon Anderson said:

I have also been playing with the TTArtisans 100mm Bubble Bokeh lens a little bit over the last 6 months and dove with it a few times in Monterey.  Hoping to shoot it more soon!  Like any manual focus lens its definitely a bit challenging to shoot underwater but has nice bokeh if your up for a challenge. It sounds like focusing is much easier on these lenses with mirrorless bodies with good focus peaking.
 

Here is my setup right now:
- Fotodiox M42 to F-mount adapter (non-optical, ~2mm flange to flange)

- Fotodiox F-mount extension tubes (14mm tube + adapters, actually measures 30mm flange to flange)
- Custom 3d printed focus gear that I designed

I used it on my D850 in Nauticam housing with the same Macro 60 port + 30mm extension ring that I use with my Nikon 105mm macro lens.  At full lens extension (closest focus) there is just barely a gap between the port glass and the front of the lens but it doesn't seem to touch. With this setup golf ball sized subjects fill the frame and at minimum focus the distance between the lens and the subject is about 10.5 in (270 mm)

Here is an uncropped example image from the setup described above. Shot at f/2.8, 1/250 sec, ISO 64
https://www.jonandersonphoto.com/California/Central-California/i-jnjrNt2/A

 

This is another image where I used a Kraken +6 diopter in front of the setup described above and cropped slightly. Shot at f/2.8, 1/250 sec, ISO 31 
https://www.jonandersonphoto.com/California/Central-California/i-pq7tFdS/A

I am thinking about revising my setup to use the more common Kenko extension tubes.  I effectively have 32mm of extension ring with the adapter,  I think others I typically use less extension ring but hard to say without knowing the thickness of their M42 adapter.  Also likely will try to use a ND 0.6 (2 stop) filter in the future to have a bit more exposure headroom.

I hope to share more on my website once I have time to get it organized.

 

Thank you Jon for sharing this, it is very helpful. I also have a Nikon D850 but with Isotta housing. Also have the port for the 60mm lens +30 mm extension ring that I use for the 105 lens. Got the TTArtisan 100mm couple of weeks ago and been trying it on land and dry runs in the housing. The photo of the hermit crab is superb! I have few questions/comments please:

 - What lighting did you use behind the hermit crab to get the beautiful bubble in the background?

- I did buy a set of Kenko extensions tubes, and again only tried them on land. They seem to be fun to play with but the depth of field becomes very narrow with every tube added. With the 36mm tube, I measured about 14" minimum focus distance to face of the lens, so a bit longer than yours at 10.5". I could get to 10" only after I piled up all 3 tubes for a total extension of 36+20+12=68 mm. That is probably a bit too much to add and obviously need for extension rings for the port (not sure is worth the investment)

- Did you set your f-stop prior to putting camera into the housing? If so, did you tape the dial?

- For the focus ring, I don't have a focus gear but I was thinking if this can be pre-set as well? For example, set the focus ring all the way to the right, the focus at the shortest distance. That way, there is no adjustments on the camera, other than getting the distance to the subject to be right.

 

Thanks!

[Jon Anderson]

On 4/9/2024 at 7:21 PM, Silvana said:

 - What lighting did you use behind the hermit crab to get the beautiful bubble in the background?

I used a piece of steel wool illuminated by Backscatter MF-2 w/ their color filters.

- Did you set your f-stop prior to putting camera into the housing? If so, did you tape the dial?
I just set it to f/2.8 and it seems to have nice detents between aperture settings so I didn't worry about taping it, its a good idea and I have considered taping it next time.   I do that on the zoom ring on my Nikon 8-15mm because I noticed it would creep from 15mm occasionally causing undesirable vignetting.  

- For the focus ring, I don't have a focus gear but I was thinking if this can be pre-set as well? 

I have heard of people doing this successfully and thinking about it I wasn't actively focusing much, just setting it for the subject size then moving the camera in and out until it looked sharp.  Definitely worth trying.  I might consider making/selling focus gears at some point but the challenge is that they likely depend on the housing, camera lens mount, and amount of extension ring used.

Interesting that you are getting such different results with the extension rings.  This is a photo of the minimum focus distance with the 30mm extension ring described above.  The distortion of my iphone lens makes it look like more than 10.5" but it was between 10" and 11" from the front of the port.  I focused the lens at the nearest focus then moved the housing until the Titleist logo on the front of the golf ball was in focus.