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Everything posted by Undertow

  1. Thanx for the help guys. I never realized that a +1 diopter meant 1 meter max focus, +2 meant 1/2 meter max focus etc.. makes sense Cheers, Chris
  2. A digital version of the Nikon 14mm f/2.8 rectilinear lens with the same angle of view (114 degrees). Like a 9mm f/2.8 or f/4 DX. They seem to do it with other lenses, the 10.5FE mimicked the 16FE, the 12-24 mimicked the 17-35 (in focal length...) and the 17-55 mimicked the 24-85...etc
  3. Hi, Does anyone know the dioptric(?) power of the Canon 500D closeup lens. I am planning to buy +3 & +2 diopters for my 12-24 and hopefully-soon-to-be-mine 17-55 in an 8" aquatica dome. I have the 500D as a closeup lens for my 80-400mm topside but I cannot find its power listed as +1,+2,+3 etc anywhere including Canon's website :glare: . Its an excellent (and expensive) closeup lens and I was wondering if it would work in place of other diopters? Cheers, Chris
  4. another for the 12-24 - i use it constantly topside. the 10.5 fisheye is a fun lens and definitely worth buying but limited in scope, so get the 12-24 first. it also compliments your range well with the 24-50, 60 & 105. Chris
  5. thanks for the thoughts and pics guys. great stuff. sounds like the 17-55 is a buy in my books once I can whip up: $1200 lens + $230 port ext + $80 zoom gear + $60 shipping + $150 customs duty & fees = $1720 yikes Thanks for the info Alex. You had me at "personally", your photos are convincing enough. I read up on a couple diopter threads and the "dome theory" piece and they sound like a good idea. Am I right to say they work on a similar principle to magic filters - adjusting a lens' focus range to better suit the dome's closer virtual image like a magic filter adjusts the camera's white balance range to better suit the colour u/w? Do you guys find that one diopter works best based solely on the dome like the article suggests? (Suggests a +3 for a 20cm/8" dome like my aquatica). Should I go solely on this suggestion or buy a +2 and try that too(for my 12-24 and later 17-55)?? What brands are best? B+W? (should i be asking this in another thread?) cheers, chris
  6. I've been told to use apple slices, rubbing the juces around the dome. I've tried it once or twice with video shots b/w above & below with good results but I don't think it lasts long on the port. I've also seen a storm chaser's raw hurricane footage (using an UW housing) where he constantly wipes the dome with a soapy wet towel (maybe baby soap) that removed the rain drops quite easily.
  7. To jump back a bit: I am also considering the 17-55 primarily as a shark lens when i manage to get back to cocos (wasn't shooting pics last time). Others seem to have success with it shooting whites & orcas from earlier posts - what are other opinions for this as a shark lens versus the 12-24 (I worry would be a bit too wide for shy hammers & other sharks). I think it would be great to get fullshots and portrait shots at the same time. Just to be clear, I only buy nikon glass. For me that's the reason I buy a nikon camera, so no thoughts of Sigma etc.. Yes, the 18-70 is a consideration but I shoot a lot of low light & action topside therefore wanting a f/2.8. Also I feel the optical difference between consumer & pro lenses may be magnified when shooting UW(is this true???). That and Aquatica charts for my D200 housing recommend a +3 or +4 diopter with the 18-70 but not with the 17-55 thus reducing the consumer lens quality further. Thoughts?? Undertow NWDiver - How was your cocos comparison b/w the 12-24 & 17-55??
  8. Sven: Though the focus on this shot is fine, using AF-S to focus and reframe U/W only works when the distance between the camera and subject stays exactly the same. This is dangerous since things are constantly moving underwater - I would suggest trying to get comfortable changing the focus areas (so easy on a D200!) and using AF-C which I always use U/W and above. The vertical crop looks much better, but there are still way too many midtones in the picture. Go to the levels command in PS and try playing with the middle slider - I think you'll be surprised at the difference it can make. Take the midtones down till it gets rid of the washed out look, then take the highlights up until the brightest areas almost go completely white. Aim in the direction of the your first edit, just be careful not to overdo it. Knowing how much to PS an image can be tough and requires practice and often an outside opinion! The more I learn the more I find myself re-editing old images often with fantastic results. (... so never delete the original!)
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