Underwater magnifiers??
#1
Posted 19 August 2008 - 10:53 AM
(actually my wife does the finding)
Does anyone have experience with them?
Prescription Masks in San Diego sells one but not sure if it is really helpful
There is also a smaller (SubSea??) that sells for $99 at Reef Photo
Does anyone have or uses one?
#2
Posted 19 August 2008 - 02:41 PM
"Downgrade, downgrade, you know it makes sense!"
Canon G9 & G7 in modified Canon WP-DC21 & WP-DC11 housings, 2 x Inon UCL-165 macro lens, no strobe, just internal flash.
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#3
Posted 19 August 2008 - 03:50 PM
There is also a smaller (SubSea??) that sells for $99 at Reef Photo
If you order direct from ReefNet, the SubSee magnifier is $75. The optics are very very good, and in light of that the price seems quite fair to me. In fact, I opted to have them make the adapter to mount it on an Ikelite flat port to use with a macro lens, after seeing the photo results Keri Wilk obtained with it and a 105mm. The mount is simple but nicely thought out, very secure, with a hinged holder that can easily swing out or into place.
Only thing is, I haven't had a chance to try it in the water yet! I'm scheming to get a Caribbean dive trip in the next few months... but may have to jump in a local puddle to look for critters.
#4
Posted 20 August 2008 - 04:57 PM
I used to have one of the SubSea magnifiers but lost it when it fell out of my jacket (I guess I didn't tie it on properly). It was OK but a bit expensive for what it does. Since then I have found that my Inon UCL-165 macro lenses work even better. The 67mm size is a bigger viewing area, they are more powerful.....
Not correct!
The Inon UCL-165 lens has a 165mm focal length, which makes it a +6 diopter. The ReefNet SubSee is a +10 diopter. That makes the SubSee more *powerful* when it comes to increasing image magnification.
More importantly, the Inon is a "wet contact" lens, meaning that the refracting surface of the lens touches water. This makes it lose almost 70% of its magnifying power as soon as it's immersed in water. By design, the SubSee does not lose ANY power when immersed in water. Yes, the SubSee has a smaller viewing area --- that's the tradeoff for higher power at a still reasonable cost.
Les Wilk
ReefNet Inc.
Edited by reefnet, 20 August 2008 - 06:40 PM.
#5
Posted 21 August 2008 - 05:49 AM
#6
Posted 21 August 2008 - 07:44 AM
There is always low tech for under $15.
Which illustrates the problem with water contact lenses. In air this is probably a nice 3X magnifier. In water it gives you very little magnification.
Les
#7
Posted 21 August 2008 - 09:26 AM
The Inon UCL-165 lens has a 165mm focal length, which makes it a +6 diopter. The ReefNet SubSee is a +10 diopter. That makes the SubSee more *powerful* when it comes to increasing image magnification.
More importantly, the Inon is a "wet contact" lens, meaning that the refracting surface of the lens touches water. This makes it lose almost 70% of its magnifying power as soon as it's immersed in water. By design, the SubSee does not lose ANY power when immersed in water. Yes, the SubSee has a smaller viewing area --- that's the tradeoff for higher power at a still reasonable cost.
Les Wilk
ReefNet Inc.
Les, I was thinking of two stacked Inons when I said it gave greater magnification. The Inon has a +6.06 diopter in water and two stacked have the equivalent of +12.12 and a focal length of 83mm. Using 250mm as the near point distance, I calculate the angular magnification as follows
Subsee (focal length 100mm, +10 dioptre) Magnification = 250/100 = 2.5
Inon (focal length 165mm, +6.06 dioptre) Magnification = 250/165 = 1.52
Inon x 2 (focal length 83mm, +12.12 dioptre) Magnification = 250/83 = 3.01
I don't think it's correct when you say the Inon loses 70% of its magnifying power in water. Perhaps you are thinking of a standard magnifying glass. In air the Inon focal length is 135.6mm, + 7.37 diopter which gives it an angular magnification of 250/135.6 = 1.84 So the magnification of a single Inon lens loses 17% of it's magnifying power in water.
I estimate that a 67mm Inon has between 3 and 4 times the viewing area of the Subsee, which I think makes it more practical to use.
"Downgrade, downgrade, you know it makes sense!"
Canon G9 & G7 in modified Canon WP-DC21 & WP-DC11 housings, 2 x Inon UCL-165 macro lens, no strobe, just internal flash.
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#8
Posted 21 August 2008 - 10:54 AM
Les, I was thinking of two stacked Inons when I said it gave greater magnification. The Inon has a +6.06 diopter in water and two stacked have the equivalent of +12.12 and a focal length of 83mm. Using 250mm as the near point distance, I calculate the angular magnification as follows
Subsee (focal length 100mm, +10 dioptre) Magnification = 250/100 = 2.5
Inon (focal length 165mm, +6.06 dioptre) Magnification = 250/165 = 1.52
Inon x 2 (focal length 83mm, +12.12 dioptre) Magnification = 250/83 = 3.01
I don't think it's correct when you say the Inon loses 70% of its magnifying power in water. Perhaps you are thinking of a standard magnifying glass. In air the Inon focal length is 135.6mm, + 7.37 diopter which gives it an angular magnification of 250/135.6 = 1.84 So the magnification of a single Inon lens loses 17% of it's magnifying power in water.
I estimate that a 67mm Inon has between 3 and 4 times the viewing area of the Subsee, which I think makes it more practical to use.
Hi Brian;
Thanks for the info. Two stacked +6's is certainly better than one +10.
I've never physically examined the Inon lens, so with regard to in-water magnification, I made inferences based on an on-line Inon spec sheet. It said 165mm focal-length water-contact lens. It didn't mention that the in-water focal length was 135mm. Can you confirm from underwater photos, with and without the Inon, that the magnification is indeed 1.84?
By the way, we tested SubSee's for extreme macro photography for a couple of months in Indonesia in May and June, with excellent results. We used hinged ABS adapters that we had made for Aquatica, Ikelite, and Light and Motion ports. In spite of its (relatively) small diameter, when the SubSee was used in front of a 105mm primary lens at closest focus there was no vignetting. We have also made and used attachments that stacked 2 SubSee's. Unreal!!!!!
Les
#9
Posted 21 August 2008 - 11:32 AM
Hi Brian;
Thanks for the info. Two stacked +6's is certainly better than one +10.
I've never physically examined the Inon lens, so with regard to in-water magnification, I made inferences based on an on-line Inon spec sheet. It said 165mm focal-length water-contact lens. It didn't mention that the in-water focal length was 135mm. Can you confirm from underwater photos, with and without the Inon, that the magnification is indeed 1.84?
By the way, we tested SubSee's for extreme macro photography for a couple of months in Indonesia in May and June, with excellent results. We used hinged ABS adapters that we had made for Aquatica, Ikelite, and Light and Motion ports. In spite of its (relatively) small diameter, when the SubSee was used in front of a 105mm primary lens at closest focus there was no vignetting. We have also made and used attachments that stacked 2 SubSee's. Unreal!!!!!
Les
Hi Les,
I didn't find the spec sheet, I picked up my info here http://www.camerasun...s/inon_m67.html
Until you started mentioning the figures, I was going by my gut feeling of using the two lenses, always a dangerous thing to do I know, but I was just offering an opinion. When you were sure the SubSee had a higher magnification than the Inon, I went off to do my sums. I'll see what I can do with photographic verification for you.
Until I lost my SubSee, I had intended to make some sort of fixture to hold it and use for macro shots. Though with the port length on my WP-DC21, I think I would have got a fair bit of vignetting and would need to zoom the G9 lens quite a bit to avoid it.
I have enough trouble with getting the focus where I want it with stacked Inon's, so I imagine it would even more difficult with stacked SubSee's. You are talking +20 dioptre, that's an angular magnification of 5, so if you got the focus, the shots must be amazing!
Cheers
Brian
Edited by BrianM, 21 August 2008 - 11:33 AM.
"Downgrade, downgrade, you know it makes sense!"
Canon G9 & G7 in modified Canon WP-DC21 & WP-DC11 housings, 2 x Inon UCL-165 macro lens, no strobe, just internal flash.
Photos Profile
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