Nauticam diopters for aps-c sensors

[Mick_G]

Hey all, just wondering if the cmc2 would provide more working distance than the smc1 on a Sony @6600 & 90mm macro lens.
Product info gives the magnification on the cmc2 as 2.8x whereas on the smc1 it’s 2.1x - i’m struggling to see how the cmc2 would provide a greater working distance (it has been recommended to me). Is there something i’m missing?

thanks

Edited October 17 by Mick_G

[Chris Ross]

The system Nauticam uses to indicate how much magnification you will get I find somewhat confusing, the port charts are the thing to use, though of course they only list the SMC diopter for the Sony 90mm macro.  However if you look at the Canon EF chart they list the SMC-1 and the CMC-2 as options for the Canon 60mm macro:

 

https://drive.google.com/file/d/1mJfA13gju8n8D_521gaxBbgK05-oeUJ9/view

 

You'll see the CMC-2 has the same magnification on the Canon 60mm as the SMC-1 but the CMC-2 has more working distance.  If you look at the Nikon 60mm macro they list the CMC lenses but it has much less working distance than the the same diopter on the Canon 60mm lens. 

 

Directionally you would expect that the CMC-2 would give you more working distance but whether or not it's significant, you would need to try it out.  If you are looking for more working distance it has been reported that the the INON closeup lenses have a little more working distance than the Nauticam lenses but again not quantified. 

 

The magnification of the SMC-1 on 90mm macro and the working distance can be found here in the Sony port chart:

 

https://drive.google.com/file/d/1M8EI7QYspv5jS0XruR2_F6BR6-Kz-HDj/view

 

The other issue is how well the CMC plays with the 90mm, there are some reports the corners are not as good on the CMC lenses as they are designed for for smaller sensors, but they are recommended on full frame by Nauticam for some applications like the 60mm macro lenses.

[Mick_G]

Hi Chris,

yep i have seen the port chart you're referring to and as you correctly state, the 90mm lens does not include the cmc2 in the various configurations relating to the use of wet lenses. 

 

I really can't wrap my head around the difference in working distance for the same cmc lens on Nikon & Canon when both using a 60mm macro lens. Physics is definitely not my strength.

 

I wasn't actually aware that the issue is the compatibility between diopter and lens although, if as you say, the cmc diopters are designed for for smaller sensors, but can be used on full frame sensors, then i guess it is really a case of comparison.

 

Thanks for the response.

Edited October 17 by Mick_G

[Chris Ross]

On 10/17/2024 at 2:49 PM, Mick_G said:

 

I wasn't actually aware that the issue is the compatibility between diopter and lens although, if as you say, the cmc diopters are designed for for smaller sensors, but can be used on full frame sensors, then i guess it is really a case of comparison.

 

Thanks for the response.

Hi Mick,

 

it appears they can be used on SOME full frame sensors.  There are reports on other threads here where it is claimed the CMC lenses don't perform well on some full frame sensors.  Note that the Canon 60mm macro is an APS-C lens while the Nikon is a full frame lens.

 

It has been discussed that the high power diopters like the SMC-1 are perhaps not the most useful lenses and that lower power lens that allow a touch more magnification than 1:1 will find many more suitable subjects.  Depends on where you are diving and what critters you want to target of course, but finding subjects for a lens combo achieving 2x+ magnification requires good spotting skills on the right dive site, preferably with an eagle eyed guide (at least for me)