Jump to content
cor

DIY small dome port for CFWA

Recommended Posts

Are there any nauticam users out there using Barry's dome?

I am aware that this would need a nexus port adapter already but,

I am interested to find out about any extension rings required for

a tokina 10-17 with or without a TC. Thanks in advance for any replies!

Cheers,

Phil

Tom (tomc) is [see above]

 

The extension is built into the Bare dome, so on the Nexus rig I can use the 10-17 with or w/o the 1.4 TC and no extension is required when adding the TC. I use the Nexus zoom gear for this lens and adapt the Nexus zoom gear for the Nikkor 12-24 with the TC. I suggest you will not need a port extension.

Bob

Share this post


Link to post
Share on other sites
Are there any nauticam users out there using Barry's dome?

I am aware that this would need a nexus port adapter already but,

I am interested to find out about any extension rings required for

a tokina 10-17 with or without a TC. Thanks in advance for any replies!

Cheers,

Phil

 

Hi Phil,

 

Yes, there are several users of my port on the Nauticam housing. Like Deep6 wrote, a Nexus port adapter is needed, but no extensions are needed for use with the Tokina 10-17 lens.

 

Barry

Share this post


Link to post
Share on other sites

After reading about Barry's excellent DIY mini dome, I decided to have a go at building one for my Ikelite setup by combining an old dome port with an old flat port. The rear end of the flat port would be used to mate with the housing, while the central portion of the 6 inch dome port would provide the curved front surface of the mini dome.

 

After some calculations/measurements I used a fine hacksaw to cut through the barrel of the flat port and smoothed the cut surface using some fine wet and dry paper on a flat surface. I then marked out a circle on centre of the dome, with diameter slightly larger than the external diameter of the barrel of the flat port (which is 4 inches). I cut out this 'circle' using about a dozen hacksaw cuts, and smoothed the cut edges of the dome, again by rubbing it on wet and dry paper on a flat surface. When the external diameter of my new dome was equal to the external diameter of the barrel (ie 4 inches), the two cut surfaces were glued together using acrylic cement.

 

Once the cement had dried I painted the barrel inside and out with flat black paint to cut down on reflection. I made a port shade out of a short piece of PVC drain pipe, re-sized for a snug fit then painted flat black.

 

Now, while the outer barrel diameter of this port might be 4 inches, the dome radius is 6 inches and I note Barry's dome has a 4 inch radius. This doesn't seem to have created a significant problem for me apart from the fact that it was designed for a Tokina 10-17 with 1.4 teleconverter, and it won't work with the Tokina on its own (at its widest the lens takes in the edges of the port). But a big plus is that it cost virtually nothing to make, and another advantage I found is that the existing Ikelite zoom gear works fine with the Tokina fisheye plus TC.

 

Sorry I didn't take a few photos of the construction phase. I've since ordered a 4 inch acrylic dome that I hope to use to make another mini dome port for the Tokina on its own, so if anyone's interested I'll post a few pics of the steps in that.

 

 

post-24764-1287526097.jpg post-24764-1287526120.jpg

Share this post


Link to post
Share on other sites
After reading about Barry's excellent DIY mini dome, I decided to have a go at building one for my Ikelite setup by combining an old dome port with an old flat port.

 

Now, while the outer barrel diameter of this port might be 4 inches, the dome radius is 6 inches and I note Barry's dome has a 4 inch radius.

 

 

Great job Casbba and what a pretty nudibranch! Looks like from the image you sent, the dome is working great. Isn't it a neat feeling to build something that works?

Wetpixel member, Bill Libecap, also was inspired by the article and has a dome for the Ikelite housing which he has found successful.

 

Just a note, my dome actually comes to 4 3/4 inch dome area on my final design. I know that is not much difference, but going larger produces a much better quality image.

 

Please keep us informed how your dome is working with different types of images as well as any other DIY projects you have created.

 

Barry

www.creativeillusionsphoto.com

www.marinekeywords.com

Share this post


Link to post
Share on other sites

Thanks Barry, and yes it is a nice feeling when you can build something yourself. I used to construct my own housings for film, movie and video cameras out of acrylic sheet. All pretty basic DIY stuff and I finally gave up when digital SLRs came on the scene and needed so many controls.

 

Having just re-read my previous post I see I got mixed up talking about radius and diameter, but I think you grasped what I was getting at. Just to clarify, my mini dome has a 6 inch diameter (not radius) and I'm using a 4 inch section of it. Hope this makes sense.

 

I'm not sure where I got the idea that your mini dome had a 4 inch diameter, but I'm interested that you say a larger diameter dome gives a better quality image. Is this because curvature of the virtual image matches curvature of the dome and so impacts on focus? If so I'm wondering if I should stick with a 6 inch diameter dome and a slightly shorter barrel for my next attempt. The problem I have with the existing one is that the port is a little long for the Tokina without a TC, and at its wider settings the Tokina catches the edge of the dome in the frame.

 

Thanks for your advice.

 

John

Share this post


Link to post
Share on other sites

I received one of Barry's domes last week and have had a chance to do a quick pool test.

I must say I am really impressed with it and the only limitation so far is the user.

:)

Hope to get some more time underwater with it soon.

Cheers,

Phil

Share this post


Link to post
Share on other sites
Thanks Barry,

I'm not sure where I got the idea that your mini dome had a 4 inch diameter, but I'm interested that you say a larger diameter dome gives a better quality image. Is this because curvature of the virtual image matches curvature of the dome and so impacts on focus? If so I'm wondering if I should stick with a 6 inch diameter dome and a slightly shorter barrel for my next attempt. The problem I have with the existing one is that the port is a little long for the Tokina without a TC, and at its wider settings the Tokina catches the edge of the dome in the frame.

 

Thanks for your advice.

 

John

Hi John,

The diameter of the dome was selected to keep the virtual image the same distance from the lens' nodal point. The virtual image is not flat, but is formed off the water/air interface curvature of the arcylic port. By keeping the virtual image the same distance all around means that the lens will focus on the same point all the way around, giving the lens only one spot to focus on. Having only one spot to focus on means all the image from edge to edge is sharp. I hope the last couple of sentences make sense. I am not an optical engineer, so my explanation may be suffering. The main point is that the image is sharp from corner to corner and edge to edge.

 

The real test of your port will be the edge to edge sharpness. Once you can figure out how to keep your distances constant, you will have your winner.

 

Barry

Share this post


Link to post
Share on other sites
Wetpixel member Barry Guimbellot (Dupsbear) has a great article on the front page about making your own small dome port for CFWA photography. The end result looks amazing.

 

Hey DIY'ers,

 

I found a cleaner looking way to seal a dome to a metal port housing. The idea is to have a small gap between the housing and the dome, but the gap is smaller at the top than the bottom. Once an o-ring is compressed into the opening, the o-ring and port are very difficult to remove.

 

110307_newseal.jpg

 

The blue in my image is a compressed o-ring that is larger at the bottom than the top.

 

The real trick is to find the right dimensions to compress the o-ring, but have enough clearance to get the o-ring in place.

 

The more pressure on the o-ring, the better the seal. This method does not seal better than the industrial superglue and silicone I used to use, but the new process looks better.

 

This is the same process that was used to seal the front glass on Nikonos 35mm and 28mm lenses, so the technique has a proven track record.

 

Happy creating,

Barry

 

www.creativeillusionsphoto.com

www.marinekeywords.com

Share this post


Link to post
Share on other sites

Hello, as someone know... I own a rare camera with a magnificent housing. When I say "rare" I mean a non common camera for underwater use.

 

I am looking for a CFWA dome for my Olympus E-3 from one year ago and... I decided to buy the Barry's dome port.

 

I know that I have some risk to don't get the expected results but... I want to try it.

 

In a couple of week I will go to Red Sea and I will can try with "real fire".

 

Stay tunned.

Share this post


Link to post
Share on other sites
In a couple of week I will go to Red Sea and I will can try with "real fire".

 

Stay tunned.

 

Hi Rajesh,

 

I hope you got some good pictures in the Red Sea.

 

I just came back from Anilao, Philippines and used the Bare Dome Port with my Tokina 10-17 lens. The combination works great, so I have included a few images.

 

The anthias next to the barrel sponge were taken at 17mm and both the other images were taken at 10mm.

 

Images were all sharp edge to edge.

 

The port is small and lightweight which handling underwater easy, not to mention packing the port for airline travel is easier than packing large ports.

 

Workmanship is first class on the port, so I would suggest it to anyone.

 

_PHI3530.jpg_PHI6335.jpg_PHI6436.jpg

 

Thanks,

Judy

Share this post


Link to post
Share on other sites

My selfmade DIY minidome for Hugyfot. :(

Thanks to Alex Tattersall and Geert Nies for parts and use off equipment.

 

minidome.jpg

 

minidomex.jpg

Share this post


Link to post
Share on other sites
My selfmade DIY minidome for Hugyfot. :(

Thanks to Alex Tattersall and Geert Nies for parts and use off equipment.

 

Nice looking dome! Have you had a chance to test the dome yet for sealing and/or image quality?

 

We look forward to hearing your of your results.

 

Barry

www.bareports.com

www.keywordworkflow.com

Share this post


Link to post
Share on other sites
My selfmade DIY minidome for Hugyfot. :)

Thanks to Alex Tattersall and Geert Nies for parts and use off equipment.

 

minidome.jpg

 

minidomex.jpg

 

Hedwig is a specialist :-)

Share this post


Link to post
Share on other sites

Hey Hedwig,

 

that's really cool!

Maybe you could write something about, how you build this mini-dome ... how did you fix the glass on the adapter?

 

I'm still looking, where I can buy a small dome ... only found a 2mm thin acrylic-port.

What ist your dome made of?

And where did you bought it?

 

I hope you understand my "perfect" english :-D ... I'm better in speaking english then in writing

 

Best regards from Germany

Share this post


Link to post
Share on other sites

Can someone explain to me (small words please, I'm feeling dumb today) why a small dome would not work on a rectilinear WA lens?

 

I'm considering trying a Sigma 8-16mm lens in a housing, and starting to research ports, and remember how much of a PITA the 8" Ike port was to pack.... Over/under shots are not enough motivator to stay big.

Share this post


Link to post
Share on other sites
Can someone explain to me (small words please, I'm feeling dumb today) why a small dome would not work on a rectilinear WA lens?

 

I'm considering trying a Sigma 8-16mm lens in a housing, and starting to research ports, and remember how much of a PITA the 8" Ike port was to pack.... Over/under shots are not enough motivator to stay big.

 

A small dome will work on a rectilinear WA lens!

 

I cannot speak to other domes, but my domes work great with rectilinear lenses.

 

 

Barry

www.bareports.com

www.keywordworkflow.com

Share this post


Link to post
Share on other sites
A small dome will work on a rectilinear WA lens!

 

I cannot speak to other domes, but my domes work great with rectilinear lenses.

 

 

Barry

www.bareports.com

www.keywordworkflow.com

Barry:

 

Thanks for the answer. I saw the comment further up in this thread by someone else, maybe on the first page. I think (having now read Alex's article on the subject) that the poster might have simply meant that rectilinear WA lenses don't give you the same forced perspective in the middle of the frame as a fisheye, hence they're not as "useful" for CFWA type shots. But the wording I read seemed more like it was saying they didn't really work behind the small domes, which didn't make sense to me. Regardless of FE vs. Rect, if the lens 'focuses' well across the field of view (not always true, wide open) I'd think a dome in the right nodal location would work regardless of diameter. Glad you can confirm.

 

Unfortunately I'm probably looking at an Ikelite housing, so I won't be able to buy one of yours... I did see your link to Bob's site though so I'll likely ping him as I get my kit together. Thanks for helping me educate myself. I've been out of the water too long and am rarin' to get back in.

 

(EDIT): I just noticed another issue that might be a factor. The Tokina 10-17 supposedly focuses in to about 5.5 inches. The Sigma 8-16mm rectilinear (the lens I'm thinking of) only focuses in to a bit over 9 inches away. Would that be problematic as the dome got smaller, especially as a bulbous front element means no diopters are possible? Given the usual 1.5x diameter rule...I think the 6" dome might be the smallest I should consider after all...?

Edited by rtrski

Share this post


Link to post
Share on other sites

Barry:

 

Thanks for the answer. I saw the comment further up in this thread by someone else, maybe on the first page. I think (having now read Alex's article on the subject) that the poster might have simply meant that rectilinear WA lenses don't give you the same forced perspective in the middle of the frame as a fisheye, hence they're not as "useful" for CFWA type shots.

 

I do not think you will have any problem with the forced perspective look with any extreme w/a lens that is focused to minimum distance. The image may not look as bulged in the center, but that can be a good thing.

 

Unfortunately I'm probably looking at an Ikelite housing, so I won't be able to buy one of yours... I did see your link to Bob's site though so I'll likely ping him as I get my kit together. Thanks for helping me educate myself. I've been out of the water too long and am rarin' to get back in.

 

I think you mean Bill's ports from uwcamera stuff.com? If so, he uses acrylic that I use and also duplicates my port shades for his deluxe shade so, his ports will work as good as mine, but for Ikelite.

 

(EDIT): I just noticed another issue that might be a factor. The Tokina 10-17 supposedly focuses in to about 5.5 inches. The Sigma 8-16mm rectilinear (the lens I'm thinking of) only focuses in to a bit over 9 inches away. Would that be problematic as the dome got smaller, especially as a bulbous front element means no diopters are possible? Given the usual 1.5x diameter rule...I think the 6" dome might be the smallest I should consider after all...?[/b]

 

I do not think you will have a problem with the close focus distance of your lens. What you are speaking of is your lens' ability to focus to infinity behind a dome port underwater. I read where someone wrote the virtual image is at 1.5X the radius at infinity, but I am not sure that is a 100% accepted distance by everyone. Through the years, I have always been told 2X the diameter of the port. Also remember that the focus distance is not from the end of the lens, but from the film or sensor plane which also adds distance.

 

I hope this information helps and does not confuse.

Barry

www.bareports.com

www.keywordworkflow.com

Share this post


Link to post
Share on other sites

Here, Wetpixel member Lill Haugen used a Bare dome port to win 1st place in the Norwegian Underwater Photo Championships 2011. Congratulations Lill!!

 

This shot shows how well a small dome handles CFWA images.

Lill%20Haugen1st.jpg

 

The small dome, like the Bare dome port will also work well with wide angle that is not Close Focus Wide Angle as can be seen by my image below.

Scubaradiomermaid.jpg

 

Seems there are lots of misconceptions about the value of a smaller dome. As can be seen above, the smaller dome works well for large scenics as well as CFWA. The only downside I have found to a smaller dome is using them for over and under shots.

 

Barry

www.bareports.com

www.keywordworkflow.com

Share this post


Link to post
Share on other sites

Your photo links aren't working for me right this second, but that may be work-computer (firewall) related.

 

I did get a dome from Bill @ UWcamerastuff. Have just tested it quickly in a pool so far, but was able to focus as close as I felt I could safely move a dome to a subject, and corner clarity looks fairly good so far (using a Sigma 8-16mm). Will post some test shots in a couple of weeks on my flickr page if I can.

 

First test shots were fixed 8mm only before I figured out how to rig a zoom sleeve (turns out the Ike 'standard' sleeve with NO clamp can 'grab' the Sigma 8-16mm zoom rubber grip toothing, if you notch it back a tad so it doesn't also impinge where there are similar rubber teethy glued to the 'fixed' collar of the lens). Haven't been back in the water to test it sleeved as well so I can see how the port works with different zoom distances.

Share this post


Link to post
Share on other sites
Your photo links aren't working for me right this second, but that may be work-computer (firewall) related.

 

Have just tested it quickly in a pool so far, but was able to focus as close as I felt I could safely move a dome to a subject, and corner clarity looks fairly good so far (using a Sigma 8-16mm). Will post some test shots in a couple of weeks on my flickr page if I can.

 

Hi Rtrski,

 

Did you ever post your shots on Flicker? If so how do I find them and how did the port work for you?

 

Thanks,

Barry

 

 

www.bareports.com

www.keywordworkflow.com

Share this post


Link to post
Share on other sites

Barry:

 

Sorry for the slow response, just got back from Dominica late last week and getting back into the work grind.

 

Photographically results of the trip were mixed - my skill, not either the DM guidance, equipment, or subject matter! I failed to think thru just how hard even a little 'snow' in the water makes truly wide angle shots, and as this was my first trip with strobes larger than Ike DS50's I've got a lot yet to learn about strobe aiming.

 

I've still got a huge number to process but the first few are up. My main Flickr page is www.flickr.com/photos/rtrski, there's a separate set for Dominica 2012 you can probably find by clicking thru various options (I hate flickr defaulting to a 'photostream' view, but what can you do).

 

Here's a couple examples at 8-9mm behind the dome. I know I disabled the 'full size' download so this is downsized significantly, but despite the obvious rectilinear 'distortion' in the corners the corner sharpness looks pretty good to my eye. Shot at f11...first image isn't cropped, second is but bottom right corner of the frame I think was the original outer corner.

 

http://www.flickr.com/photos/rtrski/685644...57629270961257/

http://www.flickr.com/photos/rtrski/685849...57629270961257/

 

Overall shots were from either the 8-16mm behind Blibecap's minidome or a 17-70mm with +2 diopter behind the typical Ike 6" dome, so I shouldn't have wasted time playing 'macro' but couldn't resist on occasion.

Edited by rtrski

Share this post


Link to post
Share on other sites

Sponsors

Advertisements



×
×
  • Create New...