Problems with Canon G11 and FIX Fisheye lens

[dhoro]

I have just returned from a dive trip, cage diving with great white sharks, at Guadalupe off the Baja. I was using my new Canon G11 in an FIX housing with an FIX Fisheye wide lens. Photos of my cage buddies ( about 4 to 5 feet away ) came out in focus and great color. However, every time a great white shark came near the cage the G11 would not autofocus and the shutter would not open. If the sharks were more distant the camera focused, the shutter open and the photos were taken. Yes, the camera was set to macro mode. Another diver/photographer onboard suggested that the failure to focus may have been due to the lack of contrast between shark and the blue water. Two other divers using a G10 and Ikelite housing and a G11 in a Canon housing with standard ports were getting excellent results. Can anyone suggest what I might have been doing wrong or what I should have done to get some exciting close up photos of large sharks within 4 to 5 feet of my lens?

 

[Nemrod]

I don't use macro mode, however, my S90 and external Fisheye lens are slightly different from your rig.

You should have shifted to manual focus and just preset the focus range and as well you should have shifted out of macro mode.

Frankly, I have had similar problems using the macro setting (with the Fisheye lens) as was suggested by another poster months back, at his request I tired it and my camera would not focus reliably.

N

 

[dhoro]

Thank you for your suggestions. I had discussed shifting to manual focus with other dive members on board the ship, but I am a novice and was not sure how to proceed. Possibly you have clarified this this with your comment 'preset the focus range'. I assumed in manual focus that I would need to be adjusting the focus and didn't see how I could do this with a shark moving toward the cage. They came to within 4 to 6 feet. In setting the focus range, if I scrolled the vertical slider to say 2 meters does the camera then focus from 0 to 2meters and thus enable me to capture the subject??
Dan

 

[Nemrod]

Thank you for your suggestions. I had discussed shifting to manual focus with other dive members on board the ship, but I am a novice and was not sure how to proceed. Possibly you have clarified this this with your comment 'preset the focus range'. I assumed in manual focus that I would need to be adjusting the focus and didn't see how I could do this with a shark moving toward the cage. They came to within 4 to 6 feet. In setting the focus range, if I scrolled the vertical slider to say 2 meters does the camera then focus from 0 to 2meters and thus enable me to capture the subject??
Dan

No, if the "slider" is at 2 meters then the subject will be in focus at 2 meters and some distance in front and behind 2 meters depending upon your f stop. High numerical f stops have greater depth of field and lower ones less. Small sensor cameras typically have great depth of field anyway. Try to shoot around f4.0 to f5.6 to increase DOF.

I suspect your focus issue was the result of using macro instead of normal. You might also try a different focus setting and exposure setting mode. Make certain that Face AiAF is OFF!

N

 

[HerraduraDivers]

dhoro,
i also belive that you don't have to use macro shooting Sharks out of a cage.
Canon states in the G11 manual:
The shooting range is approx 1-50cm (o.4 in. - 1.6 ft) from the end of the lens (when the zoom lever is pushed to the maximum)
I think that I don't want my hand and the camera lesser than 50cm/1.5 ft. from a sharks mouth.

You may should use "Quick Shot Mode" Page 61 in the Manual.
You can download the manual here: http://gdlp01.c-wss.com/gds/6/0300002536/03/PSG11_CUG_EN_03.pdf

I use non-macro mode for all shots (except macro) and never had focus problems, but i don't have the Fix housing and fisheye lens.

Chris

 

[Nemrod]

dhoro,
i also belive that you don't have to use macro shooting Sharks out of a cage.
Canon states in the G11 manual:
The shooting range is approx 1-50cm (o.4 in. - 1.6 ft) from the end of the lens (when the zoom lever is pushed to the maximum)
I think that I don't want my hand and the camera lesser than 50cm/1.5 ft. from a sharks mouth.

You may should use "Quick Shot Mode" Page 61 in the Manual.
You can download the manual here: http://gdlp01.c-wss.com/gds/6/0300002536/03/PSG11_CUG_EN_03.pdf

I use non-macro mode for all shots (except macro) and never had focus problems, but i don't have the Fix housing and fisheye lens.

Chris

Some one told him to use macro because they believe that the camera has to be set to macro to focus on the virtual image the dome provides. However, the lens he is using is not a conventional stand alone dome but instead a dome fitted auxiliary lens. The CORRECT procedure is to set the camera to normal focus mode, not macro range mode. The camera lens does NOT focus on a virtual image, it focuses/sees through the accessory lens (wet version or dry version). The optical design of the accessory lens and fitted dome already takes into account the other considerations of virtual image and close focus etc.

N

 

[dhoro]

Thank you all for your responses to my enquiry. I will certainly try setting the G11 to normal mode on my next photo/dive. I am trying to find where I got the idea that I needed to shoot in macro when using the FIX Fisheye lens, I will contact the lens distributor and discuss the matter with him. I guess I just don't know enough camera/lens theory to understand what may have gone wrong on the shark dive, like why was the camera focusing when I shot my buddy a few feet away in the cage and when I shot sharks that were 15-20 feet away?? Unfortunately, a missed opportunity for close ups of great white sharks as I will unlikely make this trip again.

 

[Nemrod]

Thank you all for your responses to my enquiry. I will certainly try setting the G11 to normal mode on my next photo/dive. I am trying to find where I got the idea that I needed to shoot in macro when using the FIX Fisheye lens, I will contact the lens distributor and discuss the matter with him. I guess I just don't know enough camera/lens theory to understand what may have gone wrong on the shark dive, like why was the camera focusing when I shot my buddy a few feet away in the cage and when I shot sharks that were 15-20 feet away?? Unfortunately, a missed opportunity for close ups of great white sharks as I will unlikely make this trip again.

Several websites incorrectly state you need to be in macro mode with a dome equipped accessory lens, however, an accessory lens like the UWL-04 or UFL165AD is not a dome, it is a dome with an attached lens through which your camera focuses.

In the macro mode you camera may not have seen enough contrast to focus, just as some of our macro photographers have found, the S90 is sometimes stubborn in macro mode. You should have switched to standard/normal mode, I bet your problem would have gone away.

Oddly, on occasion I cannot get the Inon UWL100 with dome to focus. I switch to manual focus when it acts up, it is usually during dim light or low contrast features. My UFL165AD nor the UWL-04 (yes, I have all three ) never seem to have this problem.

I think it was in the thread, Great Summer Wet Lens Shootout where I ran all three lenses against one another in both pool and real world shooting. I tried macro mode in the pool and indeed had focus issues with all three lenses and reported my findings.

View topic - The Great Summer 2010 Wet Lens Shoot Out!|Underwater Photography Guide

This is a direct quote from one of my posts in the thread:
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"Of note, I attempted using macro focus settings for the dome lenses, not so good results, I cannot suggest using a macro setting with these lenses on an S90, YRMV. The macro setting does produce acceptable focus if you are very close but, well, I will look into it more. I also shot some with preset manual focus. Now this works fine with the dome lenses, just do a zone focus because the small sensors have huge depth of field anyways and the natural huge depth of field with wide angle dome lenses added to that and the windfall is when you push the shutter button the camera shoots with no lag. Focus set at 3 feet and everything from about one foot to 12 feet and maybe nearly infinity is in decent focus at f4.0 and above."
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It is disappointing to buy an expensive rig and take it for that once in a lifetime shot, that is why I always test in the pool before I go to make sure I know what I am doing and that it in fact works! I tried to provide good and timely info, sorry you did not read my actual tests vs internet gossip.

N

 

[HerraduraDivers]

DHORO,
i have to correct my post above... Sorry for that!
I got curious and so i took some time to verify your issue with my G11 (but here on my desk and no housing or wetlens)
There is a difference in macro mode between AUTO and Av/Tv/M mode as follows:

1. G11 set to AUTO mode
Wide Angle: focus distance is 1cm-infinite/0.39inch to infinite
Full Zoom: focus distance is 30-50cm/11.8inch to infinite
- camera focuses from minimum focusing distance to to infinite
(automatic switch from macro to normal mode) depending on your zoom factor
- You can't activate macro mode manually

2. G11 set to Av/Tv/M mode
Wide Angle: focus distance is 1-50cm/0.39 to 19.6inch
Full Zoom: focus distance is 30-50cm/11.8 to 19.6 inch
- You HAVE to (dis)activate macro mode manually
- Camera will focus ONLY in the range she is set to!

Chris