Dark band in photos
#1
Posted 18 September 2011 - 09:21 AM
I also bought The Underwater Photographer by Martin Edge. in his book he says, "Make sure the water drains from the lens and housing port first or you will have a dark line across the photo." Obviously, that is exactly what happened, but I don't understand what it means.
I attached the wide angle lens before I got in the water but I could have done it while in the water. How on earth does one get something to drain when one is underwater? I must be missing something...can anyone help?
Quintana Roo, Mexico
#2
Posted 18 September 2011 - 12:47 PM
Steve
The Fin Foundation
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Canon7D & 40D, 60mm, 100mm, 17-40L, Tokina 10-17, Nauticam 7D, Sea & Sea MDX-40D YS-250's ULCS arms, Lightroom
#3
Posted 18 September 2011 - 05:00 PM
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Quintana Roo, Mexico
#4
Posted 18 September 2011 - 06:38 PM
With wet lenses I thought you wanted the 'interface' between them and the actual housing port face *completely* flooded with water. The lens structure may have a sealed air cavity, but the gap between add-on lens and housing port face needs to be consistent. Maybe that's what Martin meant, and it's just a matter of context (he meant make sure the *air* drains from between the two??) It'll probably work if there's still all air inside the gap, you just don't get quite the same field of view, but it definitely can't work with a 'mix' of air and water.
I confess I have the book (on Kindle) and haven't hardly read it yet. :/
Current rig: Sony SLT-alpha55 in Ikelite housing, Sigma 17-70mm f/2.8-4.5 DC Macro in 6" 5503.80 dome (+2 diopter optional), Sigma 8-16mm f/4.5-5.6 DC HSM behind UWCamStuff custom 5" mini-dome. Dual INON z240 Type IVs. Homebuilt LED/fiberoptic triggering.
#5
Posted 19 September 2011 - 04:05 AM
Is that a 'wet lens'? e.g. it's a Wide angle that doesn't form part of the sealed housing, but is added externally (and can be added when in the water)? If so, it kind of looks like it was partially filled with water and partially with air in the second photo, hence you have the line between the two with a different focal length on one and the other side of the border.
With wet lenses I thought you wanted the 'interface' between them and the actual housing port face *completely* flooded with water. The lens structure may have a sealed air cavity, but the gap between add-on lens and housing port face needs to be consistent. Maybe that's what Martin meant, and it's just a matter of context (he meant make sure the *air* drains from between the two??) It'll probably work if there's still all air inside the gap, you just don't get quite the same field of view, but it definitely can't work with a 'mix' of air and water.
I confess I have the book (on Kindle) and haven't hardly read it yet. :/
Yes, it is a wet lens and I had also just about decided that the word 'air' should be substituted for 'water'. It would not surprise me if that were true as my Kindle version of the book is loaded with typos and misspellings.
The next time I dive I will make sure to put the lens on under the water after getting rid of all the air bubbles. Thank you for your help.
Quintana Roo, Mexico
#6
Posted 19 September 2011 - 05:07 AM
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#7
Posted 19 September 2011 - 05:18 AM
Sorry to hear that! Was planning on using it to pass the plane time on my next dive trip (Jan) if I didn't go thru it sooner.Yes, it is a wet lens and I had also just about decided that the word 'air' should be substituted for 'water'. It would not surprise me if that were true as my Kindle version of the book is loaded with typos and misspellings.
I've noticed a lot of the Kindle books have formatting errors; seem to be using OCR instead of some sort of file translation from a digital manuscript original. Oh well, as e-books get more common hopefully they'll gradually prune them. One good thing is that as they update they will re-sync to your device. Had that happen on a couple purchases already. (of course that's a good thing if they're being *fixed* and not somehow "edited"...slippery slope when the copy isn't 'hard' anymore)
Glad to see some further confirmation from Aquapaul that you're on the right track! Welcome to the madness!
Current rig: Sony SLT-alpha55 in Ikelite housing, Sigma 17-70mm f/2.8-4.5 DC Macro in 6" 5503.80 dome (+2 diopter optional), Sigma 8-16mm f/4.5-5.6 DC HSM behind UWCamStuff custom 5" mini-dome. Dual INON z240 Type IVs. Homebuilt LED/fiberoptic triggering.
#8
Posted 19 September 2011 - 03:40 PM
Quintana Roo, Mexico
#9
Posted 20 September 2011 - 05:01 AM
If you look at your lens, you will see that it has holes to let the water in, be sure that the holes are not obstructed in some way.
If the wet lens is working correctly, you shouldn't need to do anything special in order to get the air out while you are underwater.
It could be a manufacture problem.
Andres Cuevas
Nikon D7000, Tokina 10-17, Aquatica AD7000, Aquatica Mini Dome, 2xInon Z-240 type 4.
flickr
#10
Posted 20 September 2011 - 05:29 AM
I have a wet lens with my old P&S camera.
If you look at your lens, you will see that it has holes to let the water in, be sure that the holes are not obstructed in some way.
If the wet lens is working correctly, you shouldn't need to do anything special in order to get the air out while you are underwater.
It could be a manufacture problem.
Acuevas, thanks for the suggestion. I will check it out.
Quintana Roo, Mexico
