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Alex_Mustard

Member Since 16 Jan 2003
Offline Last Active Today, 07:55 AM
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Posts I've Made

In Topic: Full Frame SLR wide angle corrector port tests

Yesterday, 04:46 AM

Optics seems to be the "next frontier" in the industry at the moment. The good news is that I know of one manufacturer who is currently developing a commercial product that is similar, in performance at least, to Alex's corrector port (although it will probably use the  Nikkor 50mm lens). The project is still in the prototype phase, but I am very confident that there will be a product for sale in the near future. I should point out that it is likely to be expensive! Once it is out, Wetpixel will be testing and using it!

 

Seems strange choice of lens. Sure a wide angle would be better? Not convinced about stretching a 50mm to a wide angle for stills (with presumably a water contact front element) will be that great for high resolution shooting. Probably OK for sub 10MP applications, like 4K video.

 

Did this lens come from a movie camera housing or a stills camera and which housing was it designed for?.....if stills what film format? I am just fascinated to know where the adaptor originated from and how old it might be? If the design truly can be used with any lens (excluding fish eye) then it is a very interesting trial indeed!

 

My glass came from an old medium format, scientific photogrammetry survey camera. But all my tests so far show it should work on a very wide range of lenses. 

 

I have probably done my last dives with the system now. So will pull together a selection of images.

 

Alex


In Topic: Full Frame SLR wide angle corrector port tests

23 January 2015 - 03:58 AM

What happend to the very corners?

They seem to have a much stronger vignetting.

 

Wahrmut

 

 

Hi Wahrmut, 

 

I don't yet have a proper mount for the internal lens of the corrector port. So I have to stick it to my camera lens with blue-tac. When I do this carelessly (for the pool tests) I get some vignetting in the extreme corners. I have commissioned two replacement lenses which are bigger and won't have this problem. The simple solution was ready for this trip, but does not work that well. So I am still using the original lens, which is a bit small and therefore vignettes if I fit it carelessly.

 

I am mainly using the 20mm for now, but have tested the Nikon 24-70mm, 16-35mm and 17-35mm with the port too. The 24-70mm is troublesome because of the barrel-length changes during zooming. 

 

I am only posting uncropped photos in this thread - as posting cropped ones (even if the crop improves the photo) would be misleading with regards to port/lens performance.

 

Here is a photo taken with the port and 20mm, of an eagle ray feeding, that I have already shared on Facebook. Again, uncropped. 

 

Attached File  CAY15_am-102571a.jpg   492.48KB   17 downloads

 

Nikon D4 and 20mm lens. Subal ND4S housing, Alex corrector port,2 x Seacam 150 strobes, 1/250th @ f/11, ISO 320.

 

Alex


In Topic: Full Frame SLR wide angle corrector port tests

22 January 2015 - 06:25 PM

Here is a video taken with the UW corrector port today, which is just a quick clip, but shows the lack of distortion with the lens and corner of the frame performance. 

 


In Topic: Full Frame SLR wide angle corrector port tests

22 January 2015 - 10:02 AM

I am slowly building up a collection of shots of different subjects shot with this lens. Many of the subjects here in Cayman are more suited to the fisheye, so I have not been using the set up that much. Took it to the stingrays this morning. 

 

Attached File  CAY15_am-105336.jpg   414.21KB   16 downloads

 

Shot stills and video and will try and upload the video when I find a CF card reader!

 

Alex


In Topic: Full Frame SLR wide angle corrector port tests

18 January 2015 - 04:08 AM

I am not planning to make these commercially, but I hope these tests prove and promote that the concept, and it is something that our community wants. Given the interest, I would hope that one or more of the existing manufacturers would take this on. 

 

Here is the setup by the pool the other day, this is with Nikon 20mm f1/8 inside.

 

Attached File  CAY15_am-102072.jpg   455.85KB   18 downloads

 

Alex