Few questions on the Nikon 18-70mm

Okay at the moment i only have a flat port. Inthis i can house both the 60mm and the 18-70mm Nikon lenses. Although I can use the full zoom range, it does give me a little bit of scope to play with. What I find more lacking in this lens is the minimum focus distance or lack thereof.

So i would like to know, what impact will it have if I use a close-up lens/filter with the 18-70mm behind a flat port? I am sure it will decrease the minimum focus distances, but what else will be happening? I guess I won't be able to focus on subjects further away, but how far will be to far away?

As a last resort, I could go the route of selling this lens and replace it with the Sigma 17-70. I know a number of people like this lens, but so much that it would be worth going this route?

Thanks

Okay at the moment i only have a flat port. Inthis i can house both the 60mm and the 18-70mm Nikon lenses. Although I can use the full zoom range, it does give me a little bit of scope to play with. What I find more lacking in this lens is the minimum focus distance or lack thereof.

 

So i would like to know, what impact will it have if I use a close-up lens/filter with the 18-70mm behind a flat port? I am sure it will decrease the minimum focus distances, but what else will be happening? I guess I won't be able to focus on subjects further away, but how far will be to far away?

 

As a last resort, I could go the route of selling this lens and replace it with the Sigma 17-70. I know a number of people like this lens, but so much that it would be worth going this route?

 

Thanks

Wide angle lenses need a dome port to work effectively. In your case, although the port will house the 18-70 it is likely that you will be restricted to maybe 40 or 50mm onwards, below which you will see the port in your picture.

When using in a dome port you will need a +4 to get the image in focus, not sure how this will work in practise, cause I never tried using my 18-70 in the flat port.

You option is really to get a dome port, quite sure flat port won't work with wide angle.. Not sure about the performance of this 18-70 or the Sigma 17-70 underwater, I am either shooting wider with the Tokina 10-17, Sigma 10-20 or using the 18-55 with a +4 (cause the 18-55 will fit the same port as Sigma 10-20).

Mmmm, I thought it was clear, but maybe not. The moment i can afford to buy a dome port I will do so!

For now I have to use what i have got and i am fully aware of the short comings there of!

All i want to know is this:

What will the effect be of using a close-up filter on the 18-70mm behind a flat port? I know i won't be able to use the full zoom range! I am more interested in knowing how it will impact on my minimum and maximum focus distances and if there will be any magnification?

Hope my question is now more clear.

Thanks

Mmmm, I thought it was clear, but maybe not. The moment i can afford to buy a dome port I will do so!

 

For now I have to use what i have got and i am fully aware of the short comings there of!

 

All i want to know is this:

 

What will the effect be of using a close-up filter on the 18-70mm behind a flat port? I know i won't be able to use the full zoom range! I am more interested in knowing how it will impact on my minimum and maximum focus distances and if there will be any magnification?

 

Hope my question is now more clear.

 

Thanks

Sorry about that. Don't know the answer and no access to sea or pool to try that out. Perhaps you can get it to a pool and try it out for yourself?

No problenm! just thought it might help in getting answers by clarifying my question.

Yes it would be an option for me to get to a pool or even the ocean...not to far away:) But i don't own a close-up lens, so thought it best to tap into the knowledge pool before going down the road of buying more gear with i don't need.

Hi Aqua Soul

I have the 18-70mm lens and I use it behind a compact wide angle port, not a dome port. I have not tried it with a close up diopter as it would not allow me to zoom in completely. Something to think about if your going to try it behind a flat port.

Mike

As my main desire with my current setup is the wish that i could have a closer focusing distance, it would seem that in the long run it would make more sense for me to chance the Nikkor lens for the Sigma then?

yes, but have you tried it yet with a +2 or +3 close-up filter (diopter) ? You might be happy with the results (closer focusing, more magnification). Like you said, your ability to focus on things far away will be limited.

you can get a set of close-up filters fairly inexpensively and try them.

good luck,

Scott