Gopro flat port vs dome port at DVinfo.net

Hubert Hofer · January 6th, 2015, 11:15 PM

Hi,
i'm getting fairly interested in the Gopro especially the latest 4k version. As I want to use it under water I wonder if anyone has used both the flat port housing & the dome port housing made by Hugyfot & Deep Pro ?
Is there much discernible image quality difference betwween flat & dome ? I would imagine the dome to offer a superior image.
cheers all

Bill Ward · January 10th, 2015, 07:12 AM

HH: as a general rule, the flat ports always outperform the dome ports underwater--domes tend to have pretty soft focus. That being no idea how well the dome port housing you mention actually works.

Hubert Hofer · January 10th, 2015, 05:25 PM

Hi Bill,
Thank you for your input. So, what the dome does is merely increase the FOV but not necessarily improve the image ? That is indeed an eye-opener. For many years dome port was the catch-cry in Uw camera housings. I bought a special UW 110⁰ wide lens that ended up very disappointingly as the image was simply too soft in comparison to the normal 75⁰ lens of the housing. I thought I had the sharpness set wrong on the camera.
Thanks again
HH
ps.
I am amazed how UW camera housing manufactures can manage to keep pace with the almost insane change of camera models just about every 6 months.

Bill Ward · January 12th, 2015, 01:04 PM

Hubert:

I checked the website, and this appears to be a dedicated dive housing, so the "dome vs flat" port argument is entirely different than the same argument when compared to go pro housings.

I've used dome port dive housings with fantastic results, but that was for more standard lens camcorders. One will just need to rent one of these Hugyfot housings and try it out to see how it deals with the wide Gopro FoV.

Hubert Hofer · January 12th, 2015, 02:23 PM

Hi Bill,

Although not GoPro related the link neverthelees is very interesting re ports.

Catalyst: Underwater Optics - ABC TV Science

Gregory Wallis · December 8th, 2015, 01:09 AM

From my understanding a dome port should give you better quality optics underwater than a flat port. Apart from regaining the full wide angle of your lens, there should be much less in the way of chromatic aberration.

The problem with using a gopro with a dome is that the focus on a gopro is not adjustable. Due to refraction undeerwater, domes create a virtual image a few inches in front of the dome itself and this is what your camera needs to be able to focus on. With a DSLR or variable focus lens you can adjust to allow for this, with a gopro you cannot. I think with a 6 inch dome the virtual image is around 12 inches in front of the gopro lens, so several inches in front of the dome. This distance is less than the gopros minimum focal distance so the image you get will be slightly soft, it's all a matter of what you deem to be acceptable. This is most noticeable when doing split shots (over/under) on the surface where an object above water will be razor sharp but where it extends below it will be soft.

I just bought a telesin 6 inch dome port for my gopro hero 3 and am very happy so far. Yes the underwater shots are a little soft, but until I find a better way then I can accept that. I did a little review of the dome port which you can read here:

Knee-deep : shallow water gopro: Review: Telesin 6" Dome Port for Gopro

Anton Shekhovtsov · December 8th, 2015, 03:57 AM

Nice review,
Btw concerning old hero2 housings: I remember seeing report from someone who slightly adjusted camera focus and position inside the housing to gain quite sharp image both under and above water. There was some kind of split shot too. Cant find the link now. I would try it myself if hero3 was compatible with old housing :\

I had impression that "round" hero2 port was indeed supposed to work, but due to all the hassle with focus micro-adjustment to get it right, it is considered failure...

January 6th, 2015, 11:15 PM	#1
Hubert Hofer Regular Crew Join Date: Aug 2005 Location: Torres Strait - Australia Posts: 76	Gopro flat port vs dome port Hi, i'm getting fairly interested in the Gopro especially the latest 4k version. As I want to use it under water I wonder if anyone has used both the flat port housing & the dome port housing made by Hugyfot & Deep Pro ? Is there much discernible image quality difference betwween flat & dome ? I would imagine the dome to offer a superior image. cheers all

January 10th, 2015, 07:12 AM	#2
Bill Ward Major Player Join Date: Jul 2005 Posts: 580	Re: Gopro flat port vs dome port HH: as a general rule, the flat ports always outperform the dome ports underwater--domes tend to have pretty soft focus. That being no idea how well the dome port housing you mention actually works.

January 10th, 2015, 05:25 PM	#3
Hubert Hofer Regular Crew Join Date: Aug 2005 Location: Torres Strait - Australia Posts: 76	Re: Gopro flat port vs dome port Hi Bill, Thank you for your input. So, what the dome does is merely increase the FOV but not necessarily improve the image ? That is indeed an eye-opener. For many years dome port was the catch-cry in Uw camera housings. I bought a special UW 110⁰ wide lens that ended up very disappointingly as the image was simply too soft in comparison to the normal 75⁰ lens of the housing. I thought I had the sharpness set wrong on the camera. Thanks again HH ps. I am amazed how UW camera housing manufactures can manage to keep pace with the almost insane change of camera models just about every 6 months.

January 12th, 2015, 01:04 PM	#4
Bill Ward Major Player Join Date: Jul 2005 Posts: 580	Re: Gopro flat port vs dome port Hubert: I checked the website, and this appears to be a dedicated dive housing, so the "dome vs flat" port argument is entirely different than the same argument when compared to go pro housings. I've used dome port dive housings with fantastic results, but that was for more standard lens camcorders. One will just need to rent one of these Hugyfot housings and try it out to see how it deals with the wide Gopro FoV.

January 12th, 2015, 02:23 PM	#5
Hubert Hofer Regular Crew Join Date: Aug 2005 Location: Torres Strait - Australia Posts: 76	Re: Gopro flat port vs dome port Hi Bill, Although not GoPro related the link neverthelees is very interesting re ports. Catalyst: Underwater Optics - ABC TV Science

December 8th, 2015, 01:09 AM	#6
Gregory Wallis New Boot Join Date: Jun 2009 Location: Melbourne, Australia Posts: 11	Re: Gopro flat port vs dome port From my understanding a dome port should give you better quality optics underwater than a flat port. Apart from regaining the full wide angle of your lens, there should be much less in the way of chromatic aberration. The problem with using a gopro with a dome is that the focus on a gopro is not adjustable. Due to refraction undeerwater, domes create a virtual image a few inches in front of the dome itself and this is what your camera needs to be able to focus on. With a DSLR or variable focus lens you can adjust to allow for this, with a gopro you cannot. I think with a 6 inch dome the virtual image is around 12 inches in front of the gopro lens, so several inches in front of the dome. This distance is less than the gopros minimum focal distance so the image you get will be slightly soft, it's all a matter of what you deem to be acceptable. This is most noticeable when doing split shots (over/under) on the surface where an object above water will be razor sharp but where it extends below it will be soft. I just bought a telesin 6 inch dome port for my gopro hero 3 and am very happy so far. Yes the underwater shots are a little soft, but until I find a better way then I can accept that. I did a little review of the dome port which you can read here: Knee-deep : shallow water gopro: Review: Telesin 6" Dome Port for Gopro __________________ Canon XH A1s and FCP

December 8th, 2015, 03:57 AM	#7
Anton Shekhovtsov New Boot Join Date: Oct 2014 Location: Kiev, Ukraine Posts: 10	Re: Gopro flat port vs dome port Nice review, Btw concerning old hero2 housings: I remember seeing report from someone who slightly adjusted camera focus and position inside the housing to gain quite sharp image both under and above water. There was some kind of split shot too. Cant find the link now. I would try it myself if hero3 was compatible with old housing :\ I had impression that "round" hero2 port was indeed supposed to work, but due to all the hassle with focus micro-adjustment to get it right, it is considered failure...