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Barmaglot

Member Since 30 Mar 2017
Online Last Active Today, 01:55 AM
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Macro - zoom with diopter, or dedicated macro lens?

06 June 2018 - 09:03 AM

I'm currently using a Sony A6300 with the 16-50mm zoom in a SeaFrogs housing (the last year's model with the fixed port), and while it works great within its performance envelope, the macro capability is... lacking, as the lens can't focus any closer than about 25cm, so I'm considering options:

 

  1. 30mm macro - would fit my current housing, and can focus down to 10cm from the sensor plane, so basically almost to the port glass, but I'm afraid that getting this close to small critters would be quite difficult, plus I'd lose the wide-angle capability.
  2. Wet diopter - Nauticam CMC-1 is quoted as having 46mm minimum working distance when in front of Sony 16-50mm, with the frame width being 26mm, but what is its maximum working distance? I read somewhere that for diopters, you take 1 meter and divide by diopter strength, so for a +15 diopter like CMC-1, it'd be 66mm, giving me a 2cm window into which the camera can focus - is that correct? What are the corresponding numbers for CMC-2?
  3. 90mm macro - it's the most powerful option, to be sure, but it's expensive ($1200 new, and it's hard to find used lenses around here - small country, small market - plus I'd need a new housing and port, although I'm probably getting that new housing anyway for the dry dome port and vacuum system capability), and as I understand it, quite difficult to use, as it focuses much slower than the little kit zoom while draining a lot of battery power - moving all that heavy glass back and forth isn't easy.
  4. 50mm macro - might be easier to use than 90mm, but I've seen some quite unflattering reviews, and I'm not sure how the part where it extends to focus will play with a port - what are the chances that, while retracted, it will start trying to focus on the port glass instead of the subject?

 

The flexibility afforded by wet lenses is really attractive - I have been on a dive where we saw a seahorse, followed by a whale shark - but I've never used a diopter, so I don't really know which way to go...


FS: SeaFrogs housing for Sony A6xxx series

06 February 2018 - 01:53 PM

This is last year's version with a fixed port - I'm upgrading to their brand new Salted Line housing with interchangeable ports. Only got to use it for about a dozen dives and some snorkeling. In original packaging with all the accessories minus the port cap which I lost somewhere. $150 + shipping from Israel. Alternatively, I'll be in New York for the next three weeks, and in Thailand in April - can ship from either of these locations if it's more convenient.

 

Also have a Meikon wet dome for it, but it's somewhat scratched up, so I'm not sure how much it's worth - maybe $30 or so? Replacement acrylic sphere from Meikon is $75.

 

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Lens for A6300?

02 February 2018 - 12:09 AM

I was rearranging stuff on a shelf and accidentally pushed my 16-50mm kit lens off it and onto the floor :fool: Now the inner telescoping part just floats in and out, so the lens is gone, and I'm flying to Thailand in two months for a week on Koh Tao followed by a five-day liveaboard to the Similans and Richelieu Rock. Oops. My housing is the Meikon/SeaFrogs one released last year, with a fixed port that can accommodate Sony 16-50mm, Sony 30mm macro or Sigma 19mm. However, Meikon just released their new interchangeable port housing for the A6xxx series, with a proper dome port and everything, even a vacuum system attachment port (a first for them), and I'm torn - do I limit my expenditure to $200 for a replacement 16-50mm lens + wet dome, or do I go whole hog with a new housing ($297), dry dome ($185) and Sony 10-18mm (at least $500-550 used) or Sigma 16mm ($450)? I also looked into Zeiss 12mm, which is cheaper used than Sony 10-18mm, but it seems that A6300 can only use CDAF with it rather than PDAF, which is kind of a deal breaker. Any other budget-friendly options that I'm missing?