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troporobo

Member Since 23 Jul 2010
Online Last Active Today, 11:16 PM
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Topics I've Started

Comparison: Olympus m4/3 macro options

Yesterday, 05:25 PM

I have been on a quest to shoot some small critters (we have pygmy seahorses at two local sites, and lots of other stuff) and looking to get ever closer. But UW gear is hard to get here and expensive and I could not find the sort of lens comparison that I needed to be confident of having the capability that I wanted. I was also curious about the running debate about the Olympus 12-50 lens and whether it is worthwhile getting the expensive Nauticam port and gear to access the 43mm macro mode or just using the 50mm normal mode plus a diopter.

 

So I put together this simple and somewhat unscientific test to show what is possible with the lenses commonly used by Olympus m4/3 shooters. Lenses are the Olympus 12-50mm zoom and 60mm macro.  Diopters are the Subsee +5 and +10. Camera is an E-M5, housing is Nauticam, and port is the Nauticam with zoom gear. The nudibranch "model" is plastic!  Cutting to the chase, here is what I found: 

 

60mm macro: Maximum native magnification obviously, diopters take it to 2.5:1 and provide closer focus but not much magnification difference between +5 and +10 diopters, very short working distance with diopters is a challenge.

 

12-50mm using 43mm macro mode: Usable native macro but not good enough for the smallest targets, not much additional magnification with diopters, working distance with diopters probably too short. 

 

12-50mm at 50mm normal mode with diopters: Using the +10 produces results very similar to the 43mm macro mode with a useful extension to working distance. However not good enough for my purposes.

 

Data and photos follow.  Full size versions can be found here: https://www.flickr.c...157656370044855

 

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60mm macro

 

 

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60mm macro with +5

 

 

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60mm macro with +10

 

 

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Looking for double flip adapter for wet lenses

12 May 2015 - 11:09 PM

I want to get a double flip adapter that will let me mount +5 and +10 wet lenses.  I'm using a Nauticam flat port with a 77mm thread at the front. 

 

Nauticam does not seem to make a double adapter (but their single adapter is very nice).  I've seen the Saga double adapter but its apparently only available with a 67mm thread and its unclear if I could mount this with a 67-77 adapter without vignetting.  The Reefnet would appear to do the job but its not clear to me how each swing arm is locked in place at either the open or closed position and whether the lenses would thus flop around, and the set screw mounting to the port looks less than robust. Neither Deeproof/Divervision not Fun-In (both in Taiwan) appear to offer a double adapter, though the swivel idea looks interesting for a single.

 

I've checked the archives but not come up with other ideas.  Are there other recent options I have missed?  Any thoughts from those who use the Reefnet double?


xenia crabs: two for the price of one

12 April 2015 - 01:28 AM

Sometimes you just get lucky.  I came across this xenia crab on a whip coral at the end of a 70 minute dive and didn't have a lot of time to work on an image. I was so intent on trying to work around toward the left side to isolate the crab against the water background that I didn't even notice the second crab until I reviewed images on a tablet later!

 

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I also failed to notice that one strobe had turned off, and overlooked the not-so-trivial fact that I had inadvertently left the lens set at f4 from an earlier attempt to experiment with bokeh on some coral.  Other than all that, the shot turned out OK! 

 

Anyway, aside from correcting the obvious rookie mistakes with lighting and DoF, any suggestions for shooting these subjects  in the future would be much appreciated!

 


low light focus tips for Olympus m4/3 60mm macro?

25 March 2015 - 04:30 PM

I've finally picked up the Olympus 60mm f2.8 macro lens and will be diving with it for the first time this weekend.  I need some tips please!

 

Testing around the house last night, the lens can be slow to focus and hunts quite a bit in low light situations. I use a red focus light at night since I'll be shooting mandarinfish which can be skittish with brighter white light and don't allow a lot of time to get the focus right.  I realize I can prefocus but that is tough to get right with a rapidly moving subject.  Is there anything I can do to improve autofocus speed in this situation? 

 

I also notice that even with the focus limiter switch set to the closest range (0.19 - 0.4 m), once it loses focus, the lens will hunt through its full range out to infinity, which doesn't seem right. 

 

BTW I'm using an OM-D EM-5, which focuses very fast with the 12-50mm lens in macro mode under the same conditions. 


Is it possible to test a wet lens above water?

17 March 2015 - 03:27 AM

This is possibly a really dumb question (but I'm OK with that): Can I test a Subsee macro lens on my housing without getting in the water?  My local retailer has the lenses and i would like to take my camera and lenses and housing to the shop to see whether any combination works for me.  I'm a dummy when it comes to lens optics so will appreciate any tips.