how to find the right diopter

[just_for_fun 0]

Hi,

 

I was wondering if someone would happen to know if there are any large (in diameter) wetmount diopters out there.

I use a Sony 717 in an Amphibico housing (58 mm lens threat) - unfortunately Amphibico discontinued this housing, so I am on my own to "improve" it further on.

On of the things I wish I had, is a wetmount diopter for macro shots. I can fit a single-element +4 diopter into the housing, however, the lens distortion is quite significant, plus I am bound to use the +4 for the whole dive.

My idea is to get a wetmount diopter lens and built a frame around, so that it will fit to the housing mount.

I just read about Woody's diopter, but I couldn't find any reliable specs on it (some say it's +2, others think it's +3 or +4, or the diameter of the lens).

Are there any alternatives out there?

 

Any help or ideas how to build your own would be highly appreciated

 

Thanks

Eric

[james 0]

"Woody's" diopter would work well. You can get one of the smaller diameter ones, and pop it out of the rubber mount. Then find a rubber cap that will fit over your port and cut it to accept the Woody's diopter.

 

Sorry, I don't know the power.

 

HTH

James

[just_for_fun 0]

Hi James,

 

thanks for the info. I saw some earlier threads regarding the customized caps. Unfortunately Amphibico decided to use a rather unusual square mount. An accessory lens sits in a frame that snaps into place. So I guess my only chance is to somehow place the lens element into a plastic framework that fits into this square mount.

Hmm - this sounds much more like a winter project than one you would want to do when the season starts kicking in

[LyN 0]

I have been using +4, +8 and +10 diopter lenses with a PT-015 Olympus housing (67mm thread) without any problems. The lenses I use are common land photography close-up lenses but, as they are made of just one element, there's no problem at all when using them underwater. Just clean them adequately after using them.

 

I have bought my lenses through eBay. If you look there, I am more than sure that you will find any close-up lens with 58mm thread that you may need. And prices are ok. Moreover, as you are only using the center of the lens (the lens is much bigger that the camera lens) no aberrations can be appreciated.

[just_for_fun 0]

Hi Lyn,

 

that sounds like a really good alternative. Although, I am surprised that this works - I would have thought that air-lenses would have a different cut than water (wet) lenses (?). - I assume you used them as wet "mount" lenses? The bigger thread would certainly help with abberations...

 

I'll look around and see if I can find a +4 or +10 to toy around

[LyN 0]

Hi Lyn,

 

that sounds like a really good alternative. Although, I am surprised that this works - I would have thought that air-lenses would have a different cut than water (wet) lenses (?).  - I assume you used them as wet "mount" lenses? The bigger thread would certainly help with abberations...

 

I'll look around and see if I can find a +4 or +10 to toy around 

<{POST_SNAPBACK}>

Yes! It works!

 

Let me show you a couple of examples of pictures taken with a +8 dipoter lens:

 

 

 

I believe you can appreciate there's no aberration or distortion due to the lens at all. And yes, I mount them as wet lenses. In fact, the space between the housing and the lens should be filled with water.

 

Look for them in eBay. You'll find quite a lot of them arround there.

[just_for_fun 0]

WOW - great pictures! That's what I was looking for B)

 

Already searching on ebay for some diopters!

 

Now I just have to built myself a frame that'll fit my rectangular port - that's what the weekend is for - right?