Seacam - Canon FF & 15mm travel possibility

As weight and bulk become ever more problematic for air travel I thought that a solution which I have adopted might be of interest to Seacam users (and similar practices could be adopted by users of other brands depending on their port options). Basically I use Canon Full Frame cameras and find that travel with a Superdome can be problematic - if I don't HAVE to carry such a big port then I do prefer not too.

So I've tried using my 5D and a 15mm Canon Fisheye lens merely using Seacam's Wideport. However, I have actually had my Wideport modified and the plastic shade has been reduced by about 2cm to avoid it appearing in the image (if you are using a 1.3x crop Canon this shouldn't be necessary). I shot with this combination using small apertures have found that results at f/16 were surprisingly good - only very marginal extreme corner softness and chroma, which I'd suggest are unlikely to be a problem in the vast majority of images. Given the cleanliness of today's sensors at higher than base ISOs, then f/16 is not an untenable aperture to use and for anyone who is interested, the attached images were taken using a single diffused SB105 strobe unit (at the price these strobes now go for they go in my main baggage - dive bag). I found no problems with any back reflections as the photos also show, even when shooting against the sun.

Whilst I haven't experimented at much wider apertures the few shots I have tried indicate that whilst its possible to get reasonable results even at wider apertures, corner and even edge problems can show up so if edge or corner detail is important and wider apertures are essential then a larger dome may be more desirable, but for centered subjects in mid-water the wideport should be usable even so. Obviously, being limited to small apertures is not going to suit every situation nor will it be to everyone's taste so this is an option if you are prepared to accept this limitation.

Back when I was shooting Canon 5D’s, one of my favorite work arounds with the Canon 15mm fisheye was incorporating a Tamron 1.4 telaconverter on the back it with a 15mm extension ring added to the Subal FE-DP port. Basically it gave me two different primes – 15mm Fisheye and 19mm fisheye while taking up the space of one lens in the bag.

I suspect you would be able to do the same with the seacam wide port.

Which wideport? The 4" or the official "wideport?"

Cheers

James

Hi James

The 'official' Wideport - Seacam produce Domeports (DP), the Wideport (WP), the Fisheye Port (FP) and the Superdome (SD). So I'm referring to the Wideport here which is bigger than the smaller Domports but not nearly as bulky as either the Fisheye Port or Superdome.

I have the 4" DP which is REALLY small. I have shot it w/ the Sigma 15mm fisheye before but haven't analyzed the results.

Cheers

James

Back when I was shooting Canon 5D’s, one of my favorite work arounds with the Canon 15mm fisheye was incorporating a Tamron 1.4 telaconverter on the back it with a 15mm extension ring added to the Subal FE-DP port. Basically it gave me two different primes – 15mm Fisheye and 19mm fisheye while taking up the space of one lens in the bag.

 

I suspect you would be able to do the same with the seacam wide port.

Good point Walt. Now that I'm shooting the 1DsMKIII and a 1DMKIII in same Seacam housing, I could essentially go on location with one lens, wide port and small port extension for Tamron teleconverter, and have 4 optics (2 each, FF and 1.3 crop). Add a Sigma 50mm for 1:1 macro capability (which also works behind the wide port and small port extension) and I'd be covered for macro, fish, and a wide variety of wide angle subjects (all with nice corner performance). I'll have to try that sometime soon. Thanks for the reminder.

James

I'll try some smaller domes too - I do have a very short Domeport.

And perhaps a 1.4 converter might be a good idea....

For those that have been shooting FF digital with Seacam housings:

What is the shortest rectilinear focal length producing good results at modest apertures, e.g., f/8, with the WP on FF? Hopefully 20mm, which gives one Nikonos 15mm capability. The 14mm (~20mm on FF) works very well with the WP on DX format, my most-used set-up.

On my last trip to HI, I brought just the WP and 105mm FP (plus one port extender) for my D2X housing. I carried my whole UW rig in one backpack including 2 Inon strobes. One body and lens also traveled in the housing in the backpack (carry-on). My laptop (17") bag had the camera gear balance and chargers (2nd carry-on). Yup, it was heavy, but since I am a big boy, over 100 kg, it was not a problem

Tom .

I have the 4" DP which is REALLY small. I have shot it w/ the Sigma 15mm fisheye before but haven't analyzed the results.

 

Cheers

James

They might be described as tiny! If one was going on a trip with just one day or so of diving a DP could be good choice or just a FP (if no wide-angle shooting is planned). Back in film days I traveled once with just one RS and 50mm lens when diving was going to be limited to one day. It depends on what one is most interested in shooting - I do more macro in the tropics being a biologist.

Tom

For those that have been shooting FF digital with Seacam housings:

What is the shortest rectilinear focal length producing good results at modest apertures, e.g., f/8, with the WP on FF? Hopefully 20mm, which gives one Nikonos 15mm capability. The 14mm (~20mm on FF) works very well with the WP on DX format, my most-used set-up.

 

On my last trip to HI, I brought just the WP and 105mm FP (plus one port extender) for my D2X housing. I carried my whole UW rig in one backpack including 2 Inon strobes. One body and lens also traveled in the housing in the backpack (carry-on). My laptop (17") bag had the camera gear balance and chargers (2nd carry-on). Yup, it was heavy, but since I am a big boy, over 100 kg, it was not a problem

Tom .

Tom

I've settled on Canon's 24/1.4 as my 'standard' wide but the 20mm is ok (unfortunately not one of Canon's best lenses - I think that the Nikon equivalent is probably a better lens). 20mm (90 degree field of view) on Full Frame is generally regarded as being about the limit for 'reasonable' corner correction (both practically and theoretically) but given sensor requirements I'd say that f/8 is likely to be no more than adequate if you have detail in the corners and this will depend on subject matter too - I used to use my 20mm at f/11~16 if at all possible.

I took the Wideport and a 100mm Port (made up from a Flat Port + 2 Extenders) with 15mm and 100mm lenses on my most recent trip and carried most essential gear in hand luggage (limited to 5Kg now by many UK airlines) and a multipocket coat (though the wideport did bulge a bit in a pocket, and I do know that I have an S45 in another pocket!). With hindsight I would have taken a 35mm f/2 lens too as this makes for a very compact package behind a 40mm long Flat Port and is surprisingly useful. The 35/2 is also used by biological surveyor friends who do find it extremely useful for habitat shots in poorer visibility.

Paul, I think you will get better results with the Canon 15mm fisheye with the Tamron 1.4 telaconverter on the back then you will from the 20mm, especially in the corners while still getting the same degree of coverage.

Thanks Walt, I'll add this combination to "the things to look out for and do" list which only ever seems to get longer. I'm sure that you are right - I didn't like the 20mm Canon at all, but the 24/1.4 works well and gives a very bright viewfinder image which I really value in UK waters.

Paul, try the Sigma 20 f1.8... I find it to be sharper than the Canon.

HI Paul,

I have started to use the WP with a 10/17 fish eye without any modifications to the shrouds,

I have used it on the 10mm end as at the time I did not have a zoom gear but the images I have

so far I am happy with it.

Andy

Andy, the thread is more about FF and 1.3 crop than 1.5 crops.

Paul, I'll be trying the Tokina 17mm f3.5 with FF soon in a "custom" 8" acrylic dome on the seacam. The acrylic cuts weight by 1/2[/] (a gross over-exaggeration, probably weight savings of perhaps 500g if that) and allows me to use the Sigma 12-24 on FF and 1.3x. The 17 on the 1.3 crop was very nice corner wise even down to f5.6. Will let you know how it goes.

Surely the problems of Seacam Fisheye + dome issue is the same whether you have a 180 degree 10-17mm on 10mm on a 1.5 crop or a 180 degree 15mm FE on a FF.

Since the original post was about testing a WP with a Fisheye, comments confirming this works on a cropped sensor (also seeing 180 degrees is a valuable addition).

I realise that the subject has also gone on to cover wide angle rectilinears too.

I was pleased to see Seacam now have the 4" fisheye dome, too.

Alex

My reply to Andy was too curt and I apologize for that. That'll teach me to post while rushing out for xmas eve dinner.

For the dome issues with FF/crop, isn't the point of the matter about size? With a 1.5/6 crop sensor, the smaller dome will generally work better due the focal length needed for FOV. The point of Paul's post to me is to see how much we can get away with FF fisheye/WA with smaller domes. Not that I want to start yet another FF vs crop debate.

The 4" dome port was originally designed for the 24mm and not fisheye. The wideport is for the 20mm but Seacam even mentions the 14mm rectilinear of the sigma, presumably because of the closer MFD 18cm vs the Canon's older 14's 25cm (the new 14 II is 20cm).

The issue of weight/size and performance ratio is pretty pertinent to those who travel often by airlines and don't have their own G5. How I wish the 4" dome is all I needed. But maybe the wideport is good enough for the 17mm which is all I personally really want.

I have a DP60 Domeport from Seacam which is overall ~13cm diameter and protrudes only 5cm from the housing - I've fitted a 15mm Fisheye behind it and it just fits! I'll give this a try when I get into some water with viable visibility, as it would make an even more compact set-up altogether, and see if the results at small apertures are acceptable. I also have a very short P40 Flatport which I now use with extenders for various macro lenses and the 35mm f/2. I foresee some experimentation coming on this year.

Surely the problems of Seacam Fisheye + dome issue is the same whether you have a 180 degree 10-17mm on 10mm on a 1.5 crop or a 180 degree 15mm FE on a FF.

 

Since the original post was about testing a WP with a Fisheye, comments confirming this works on a cropped sensor (also seeing 180 degrees is a valuable addition).

 

I realise that the subject has also gone on to cover wide angle rectilinears too.

 

I was pleased to see Seacam now have the 4" fisheye dome, too.

 

Alex

I have used the Seacam WP with the 10.5 as have others on this forum, I believe.

The 4 inch wide DPs, however, are NOT fisheye domes. They have a relatively large radius of curvature, which SEACAM does not bother to specify. The DPs are supposed to be used with modest wide angle lenses (i.e., not super-wide).

The SEACAM fisheye port (180 degree hemisphere) is about 6 inches in diameter, smallish but not tiny.

The pix near the top of this web page show a short DP on a housing:

http://www.seacamusa.com/products.shtml

There are different DP models that vary according to their length (made for different lenses), hence the use of plural above.

I think there may be confusion because essentially ALL non flat housing ports are dome ports. The DP is better described as a 'narrow angle dome port' but that is quite a mouthful.

Merry Christmas!

Tom

Wouldn't a dome port work for macro as well? I mean with a wideport and a few extension rings, it could be all that is needed for a trip that doesn't need over/unders, SWA/FE shots.

Paul, can you try the Wideport with a 14 to see if that's workable?