Problem using Nauticam CMC-1

[Helene 0]

Hello,

 

I have a Canon G16 with a Nauticam housing and recently acquired a Nauticam Compact Macro Convertor 1 as well as a single strobe Inon Z240.

 

I am hoping you can help me with some questions I have using the CMC-1.

 

1. Circular mark in corner of pictures (please see pics attached)

Every time I use the CMC, a bright circular shape appears in the corner of my pictures. Would you know what is causing this? Could it be the position of the strobe which is reflecting on the lens?

I have to be very close to the subjects when I use the CMC and need to point the strobe very close to the lens. Could that be the issue?

 

2. Distance to subject

How close are you supposed to be to the subject when using the CMC-1 with a compact camera? I usually have to be about 1 to 2 centimetres close which I find too close. What do you think, is this normal?

 

Many thanks for all your help!

 

Helene

 

 

Edited April 10, 2016 by Helene

[tursiops 81]

Try moving the strobe back, so it is not in front of the camera.

Try zooming out as much as possible to get some more standoff distance.

[Helene 0]

Hi Tursiops,

 

Many thanks for the tips. I will try moving the strobe behind the camera.

 

As for the CMC, if I do not zoom enough, there is a black tube appearing around the picture (distance between the 2 lenses as I am using a flip diopter holder). To avoid having this, I am forced to zoom to about half way through the maximum zoom point. Is this normal?

 

Sorry for all my questions, I really want to fully understand how to correct my mistakes :-)

 

Thank you,

Edited April 9, 2016 by Helene

[kc_moses 142]

When using a macro diopter, it's common that you would zoom all the way out to get the most magnification. In the photos you posted, if you zoom all the way out, you could easily fill the frame with the whole creature. Remember, when come to macro, it's about getting close. Depends on the subject and their size, 1-2 cm is reasonable.

[Helene 0]

When using a macro diopter, it's common that you would zoom all the way out to get the most magnification. In the photos you posted, if you zoom all the way out, you could easily fill the frame with the whole creature. Remember, when come to macro, it's about getting close. Depends on the subject and their size, 1-2 cm is reasonable.

 

 

The problem when I zoomed out is that I had a "black tube" appearing on the outer parts the images. Would you know how to avoid that? I am using a flip diopter holder.

 

Hoping you can help me

 

Thanks

[TimG 62]

 

 

The problem when I zoomed out is that I had a "black tube" appearing on the outer parts the images. Would you know how to avoid that? I am using a flip diopter holder.

 

Hoping you can help me

 

Thanks

 

 

Can you add a picture of this, Helene? Is it a reflection?

[kc_moses 142]

Sorry, I mean zoom IN, use the longest focal length.

 

 

 

The problem when I zoomed out is that I had a "black tube" appearing on the outer parts the images. Would you know how to avoid that? I am using a flip diopter holder.

 

Hoping you can help me

 

Thanks

[Helene 0]

 

 

Can you add a picture of this, Helene? Is it a reflection?

 

Hi,

 

Attached is a picture using the CMC when I do not zoom in. A "black tube" appears in the picture.

 

Are you always supposed to fully zoom in when using a diopter?

 

Many many thanks for all your help everyone, much appreciated!

 

Helene

 

[troporobo 245]

I see two issues:

 

First, you need to zoom in further (longer focal length) to eliminate the vignette. The wider focal length is picking up the CMC body. You can easily test this on land.

 

Second, it looks like the strobe is indeed causing a reflection. Remember that the strobe puts out a cone of light. You don't want that cone illuminating the front of the CMC. Aim it more forward, and if possible place the strobe behind the front of the CMC.

[Helene 0]

Thanks all, it makes sense!

 

I will zoom in further and will try to play with the position of the strobe. I find it very hard to position it with a subject being only 1 centimetre away from the lens. Would you position it very close and behind the front of the CMC, in the centre, or would you extend the arms to put it further away?

 

Again, thank you all for your insight, much appreciated!

[Interceptor121 769]

The G16 has 140mm equivalent focal length this is very long.
According to Nauticam chart you should be able to work at 59mm distance. If you are closer it is likely you are zoomed out

The G16 with CMC achieves 19mm frame width which is good for pygmy seahorses but for the majority of subject is too strong

For example you should be shooting the detail of the nudibranch if you try to fit it all in the frame and zoom out you end up on the edges of the lens

Looking at the picture it seems like the strobe is on the right side as the shadows are on the left and is going through the lens creating reflection

Can you look at the exif and post the focal length of all those pictures?

[troporobo 245]

Also keep in mind that you don't want to use the CMC for every subject. For example, that last shot of the nudi, you probably didn't need the CMC and could have shot it with the lens zoomed in, whereas using the CMC caused you to have to zoom out but then you get the vignette. With your camera, you probably only need the CMC for really small critters or really tight details on larger critters.

 

When I shoot super macro, I almost always have the strobes pulled in very close to the port, a little (like 10 cm) behind the glass, and aimed straight ahead, or even a little outward from straight. If you were looking straight down on my rig from above, the strobes would be pointing like the outer legs of the letter "W".

[Helene 0]

Thank you all for your help on this. I may need a bit more help from you to explain some terms. I am just beginning and do not fully understand all the technical terms (focal length, focus distance, etc). I will get there but just need a little bit more help :-)

 

Here is what I understood:

- The reflection was caused by the position of the strobe.

- The vignette is seen because I did not have enough zoom in to get a tiny detail of the large nudibranch or the nudibranch was too large to have it in full using the CMC

I understand this and I am very grateful for the explanations you sent, thank you.

 

Here is where I need more help from you:

- What does the minimum focus distance mean vs. the use of the zoom? It is 10mm without CMC and 59 mm with CMC. Does it mean I can get the same level of details with the CMC being a bit further away from the subject, at 59mm? Does this distance imply using the zoom or not? I just tried and I can be closer that 59 mm with the CMC with a zoom in.

- 19mm frame width using CMC: does it mean that any subject larger than 19mm will not fit entirely in the frame? Is this distance using the zoom or not? Without the CMC, it can get to 30mm which I also do not get since I can easily fit a shark in the frame. I assume this is therefore implying using the maximum zoom in?

 

Here are the details of the pictures I posted above:

- xeno crab: focal length = 9.89 mm

- shrimp: focal length = 9.89 mm

- nudibranch: = 7.59 mm

 

Apologies for my ignorance and all my questions! I am very keen to understand all this as this is the only way I will understand how to best use my equipment.

 

Once again, many many thanks for your patience and time!

 

Helene

[Interceptor121 769]

Thank you all for your help on this. I may need a bit more help from you to explain some terms. I am just beginning and do not fully understand all the technical terms (focal length, focus distance, etc). I will get there but just need a little bit more help :-)

 

Here is what I understood:

- The reflection was caused by the position of the strobe.

- The vignette is seen because I did not have enough zoom in to get a tiny detail of the large nudibranch or the nudibranch was too large to have it in full using the CMC

I understand this and I am very grateful for the explanations you sent, thank you.

 

Here is where I need more help from you:

- What does the minimum focus distance mean vs. the use of the zoom? It is 10mm without CMC and 59 mm with CMC. Does it mean I can get the same level of details with the CMC being a bit further away from the subject, at 59mm? Does this distance imply using the zoom or not? I just tried and I can be closer that 59 mm with the CMC with a zoom in.

- 19mm frame width using CMC: does it mean that any subject larger than 19mm will not fit entirely in the frame? Is this distance using the zoom or not? Without the CMC, it can get to 30mm which I also do not get since I can easily fit a shark in the frame. I assume this is therefore implying using the maximum zoom in?

 

Here are the details of the pictures I posted above:

- xeno crab: focal length = 9.89 mm

- shrimp: focal length = 9.89 mm

- nudibranch: = 7.59 mm

 

Apologies for my ignorance and all my questions! I am very keen to understand all this as this is the only way I will understand how to best use my equipment.

 

Once again, many many thanks for your patience and time!

 

Helene

 

Your lens is zoomed out. The G16 range is 6.1-30.5 you are at the wide end close to the vignetting point. Closer to the black vignette the lens has another glass area not clear it is likely this is your reflection.

Because you are not zoomed out the camera working distance is around 1cm so to go further away you need to zoom fully.

 

Frame width 19mm means anything bigger will not fit the frame

 

In short I do not know who advised you to get the CMC for the majority of subjects you will achieve less than the traditional macro frame width of 35mm with a single Inon UCL-165 so unless you live in pygmy seahorse land the CMC will be too much for you and a weaker lens could have been sufficient.

[Helene 0]

Thanks for these details. I think I understand now. Just need to play a little bit with the equipment to put it in practice.

 

I was indeed in pigmy seahorse and other macro dreamland (Wakatobi in Sulawesi) when I was advised to acquire the CMC ;-)

 

Not a bad acquisition, I just needed to fully understand how it works and I thank you for your patience to explain me.

 

 

 

Your lens is zoomed out. The G16 range is 6.1-30.5 you are at the wide end close to the vignetting point. Closer to the black vignette the lens has another glass area not clear it is likely this is your reflection.

Because you are not zoomed out the camera working distance is around 1cm so to go further away you need to zoom fully.

 

Frame width 19mm means anything bigger will not fit the frame

 

In short I do not know who advised you to get the CMC for the majority of subjects you will achieve less than the traditional macro frame width of 35mm with a single Inon UCL-165 so unless you live in pygmy seahorse land the CMC will be too much for you and a weaker lens could have been sufficient.

[hijodelmar 0]

On 4/10/2016 at 6:49 AM, troporobo said:

o eliminate the vigne