Sigma 15mmFF AF Problem

I have a 15mmFF Sigma lens, in an Ikelite housing, using the 5503.15 (fisheye) port.

I had focus issues (it would hunt, then freeze at the inf end of focus, and the camera coun't un-stick the focus ring). So I took the lens to C.R.I.S. (sigma service center), they replaced a few parts, and the lens appeared to be working just fine (above water).

Trip to bonaire, dive on the Hilma Hooker Wreck.. lens seems to be working ok, then it starts not focusing at all, will just display the <> in viewfinder, never locking on... at end of dive, it starts focusing fine once the depth was less than 30'.

Could the AF be affected by the (minimal) compression of the housing due to depth? or do I need to have the lens looked at (again)? It works fine above water. Or do I just give up on AF, and use MF with this lens?

Art.

Hi,

I'm using this lens in my ike housing and have not ever had any problems. Heck at the moment its my favorite lens to use. Just for your information, this is with on a Nikon D70 with the 5503 port, which is the same as your port but with the sun shade.

Sorry I couldn't be of any help, but I think the lens needs to go back to C.R.I.S. again

Stephen

Art,

You have the wrong port, and the "apparent image" created by the Superwide #5503.15 port is likely closer than the minimum 5.9" the Sigma 15mm lens focuses to.

The correct port is the "standard" #5503 dome port.

See a couple pics at the link at www.haasimages.com

Hope this helps!

dhaas

Agreed. This is the wrong port. I use mine (on a D70) in the 5503 port without any problems. The 5503 port is not the same as the 5503.15 with a sun shade contrary to what the user above stated. The 5503 port is longer than the 5503.15. The 5503.15 is for 180 degree fisheyes like the 10.5mm. The 5503 is what you need.

You don't state which camera you are using. If you are using a full-frame camera, like the 5D the 8" dome port is the only solution for this lens. On digital crop cameras the 120 degree FOV is fine in this port. But on FF, with 180 degree FOV, removing the shade is not enough. You need the 8" dome with the FE extension.

the camera is a (gasp) film .. nikon n90s (Yes, I know this isn't the film forum, but its not very active) I have a prototype 8" port, it doesnt work very bad vigineting as seen here , this one shows that it works ok at the surface behind the fisheye port, and this is manual focus, behind the fisheye.

I'd like to get the AF going, too much other things needing attention in the cave to concentrate on MF also.

this is a pic of the port, (which I purchaced used, with the housing, 8" port (also shown on that page) camera etc.

Agreed. This is the wrong port. I use mine (on a D70) in the 5503 port without any problems. The 5503 port is not the same as the 5503.15 with a sun shade contrary to what the user above stated. The 5503 port is longer than the 5503.15. The 5503.15 is for 180 degree fisheyes like the 10.5mm. The 5503 is what you need.

 

You don't state which camera you are using. If you are using a full-frame camera, like the 5D the 8" dome port is the only solution for this lens. On digital crop cameras the 120 degree FOV is fine in this port. But on FF, with 180 degree FOV, removing the shade is not enough. You need the 8" dome with the FE extension.

First and foremost you have some really nice shots in your galleries. Great work

I couldn't find the 8" port you mentioned in your gallery. The picture you linked is definately the 5503.15 (6" port for fisheye lenses). I know Ikelite made some prototype 8" ports in 2005. I don't know anything about these. The one I have is their production version. A user here with a 5D (Full-frame) and Ikelite housing reported that the production 8" port and fisheye extension was the only solution with the 15mm Sigma and a full frame.

I don't understand what you mean when you show one shot above water with no vigenetting and underwater with vigenetting. Is this the same port? I don't see how being topside or underwater matters for vigenetting.

the shot with vigenetting was with the 8" port, shown here (all photos on this page, except the first 2)

First and foremost you have some really nice shots in your galleries. Great work

 

I couldn't find the 8" port you mentioned in your gallery. The picture you linked is definately the 5503.15 (6" port for fisheye lenses). I know Ikelite made some prototype 8" ports in 2005. I don't know anything about these. The one I have is their production version. A user here with a 5D (Full-frame) and Ikelite housing reported that the production 8" port and fisheye extension was the only solution with the 15mm Sigma and a full frame.

 

I don't understand what you mean when you show one shot above water with no vigenetting and underwater with vigenetting. Is this the same port? I don't see how being topside or underwater matters for vigenetting.

Yup this is the prototype 8" port, complete with the goopy silicone caulking. It looks to me like the port extension is longer than the FE dome that I have and certainly too long to fit a 180 degree wide lens. It looks like it would vigenette. Unfortuntely it doesn't look like you could physically get the dome closer to the housing though.

I'm out of ideas. email Ike from this forum. He is very quick to respond. I have no experience with film SLR housings. I know that people used this lens with that housing in the past. Unfortunately all the old film port charts are no longer on the Ikelite website.

Ask Ike if the new 8" production dome will fit the film housing and if he will exchange it.