Canon S90 w/ lenses Pool Practice
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skynscuba
Contributor
Yes, I think that is what he is saying, it sounds like with the Ikelite housing that it is required to zoom to about 45mm approximately. This is because the Ikelite port places the lens a bit further out than ideal.
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dogdrjohn
Contributor
Nemrod
Speaking of ideal placing, what is the approximate distance from the front of the front rotating ring to the port glass with your FIX housing? On my Canon housing I measured roughly 2.9 cm from the front of the front control ring to the inside of the port glass, which I believe is double glass, then another 4mm for the front bezel. But both of my AD lenses (105 AD and UCL-165AD) project 3-4 mm inside the INON AD28 mount so they are very close to the front of the port glass. I don't have my metric ruler handy, but with a tape measure I measure 2 & 11/16 inches from the back of the camera to the front of the lens port bezel (the back of the camera is nearly flush with the housing opening). The camera body is 1 & 3/16 inches deep, including the front control ring. So that makes it about 1.5 inches or 3.8 cm from the front of the control ring to the front of the bezel. Subtract 4 mm for the bezel, and maybe another 4 mm for the double glass and that leaves about 3.0 cm from the front of the control ring to the inside of the glass, pretty close to the 2.9 cm I measured yesterday. It appears Canon did a pretty good job with their housing of getting the camera lens as close as possible to the inside of the glass with little risk of the lens hitting the port glass at full extension, which I have read makes the camera's motors and gears and brain very unhappy. I do have to say that this is the best INON mount I have seen - heavy aluminum over 1/8 inch thick that fits very tightly over the port. If I were to use it on the camera just for a mounting point for a small hot shoe foot to a focus light and the strobe synch cord I would feel there is NO danger of it coming off. A big and heavy lens would eventually loosen it, I imagine, but even then it wouldn't come off easily.
Speaking of ideal placing, what is the approximate distance from the front of the front rotating ring to the port glass with your FIX housing? On my Canon housing I measured roughly 2.9 cm from the front of the front control ring to the inside of the port glass, which I believe is double glass, then another 4mm for the front bezel. But both of my AD lenses (105 AD and UCL-165AD) project 3-4 mm inside the INON AD28 mount so they are very close to the front of the port glass. I don't have my metric ruler handy, but with a tape measure I measure 2 & 11/16 inches from the back of the camera to the front of the lens port bezel (the back of the camera is nearly flush with the housing opening). The camera body is 1 & 3/16 inches deep, including the front control ring. So that makes it about 1.5 inches or 3.8 cm from the front of the control ring to the front of the bezel. Subtract 4 mm for the bezel, and maybe another 4 mm for the double glass and that leaves about 3.0 cm from the front of the control ring to the inside of the glass, pretty close to the 2.9 cm I measured yesterday. It appears Canon did a pretty good job with their housing of getting the camera lens as close as possible to the inside of the glass with little risk of the lens hitting the port glass at full extension, which I have read makes the camera's motors and gears and brain very unhappy. I do have to say that this is the best INON mount I have seen - heavy aluminum over 1/8 inch thick that fits very tightly over the port. If I were to use it on the camera just for a mounting point for a small hot shoe foot to a focus light and the strobe synch cord I would feel there is NO danger of it coming off. A big and heavy lens would eventually loosen it, I imagine, but even then it wouldn't come off easily.
I measure 6mm (2 6/16) from the back of the S90 camera installed in housing to the front of the FIX port, exterior side. There is no bezel on the port, it is flush essentially with the port lens. (Actually there is a bezel, it is plastic and comes off to expose the external threads for the FIX adapter kits).
Yes, the FIX places the lens of the camera closer to the port lens and thus closer potentially with the accessory lens. The combined length is less than either the OEM or Ikelite housing, this is why the 165AD lens works without vignetting when installed on the FIX90 and the other two, not as well or at all.
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Yes, the FIX places the lens of the camera closer to the port lens and thus closer potentially with the accessory lens. The combined length is less than either the OEM or Ikelite housing, this is why the 165AD lens works without vignetting when installed on the FIX90 and the other two, not as well or at all.
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skynscuba
Contributor
If dogdrjohn measured the back-bezel and bezel-front of port accurately, and Nemrod did, I come up with the outside (front) of the port glass being 4mm further for the Canon than for the Fix. Assuming that the wet lens needs to be very close to the port for "optimal" positioning, an extra 4mm is going to cause a lot of edge blur. See page 19 of http://www.inon.jp/_userdata/DL_PDF/inonlens2009_en.pdf, where they show an example with 5mm offset from ideal.
I think when they say 5mm they mean from the wet lens rear element to the port lens face. My (DIY) AD lens adapter places the wet lens element about 2mm from the port glass and the 10Bar about 3mm. I measured this and reported it, this is just what I recall. This is a good thing because it keeps the wet lens close to the camera lens when it is zoomed to 35mm (the S90 lens retreats slightly during the initial zoom from full wide 28mm to 35mm).
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skynscuba
Contributor
No, on page 19 of the Inon reference, they don't say anything about ports or distance to ports. They just say they took a first photo "at correct position," and a second photo "intentionally attached on 5mm away from correct position." The difference in the photos is huge.
I wish they would publish the spec for the correct distance, but I guess they just want to "take care of everything for us" and sell us a mount base for and OEM housing. I would send them the question, but couldn't find any address to send it -- they just say contact a dealer for questions.
Yes, I see, you are right, I misunderstood, my glasses needed cleaning also.
In any case, I am pretty sure the accessory lens elements are closer with the FIX due to the compact port design it has and precise engineering.
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