Macro lens ratios.

I have no doubt the answer to this question will be a lot less straighjt forward than I hope.

As I have not yet purchased my macro lens (got the funds, still not decided which), I still play at macro using a 1x4 close up filter attached to a Nikon 18-200mm lens used at 200mm.

The lens itself produces images at 1:4.5 ratio.
Does that mean a 1x4 close up filter attached will give me a 1:1 result at 200mm?

I have never had the chance to see what a 1:1 result looks like though a viewfinder with a true macro lens attached because my local photographic equipment retailers do not stock the lenses I am interested in to try on my camera body,therefore I cannot compare the filter against the true macro lens.

Keith

Hi Keith,

It's a shame you're quite so far away, I have recently acquired a couple of old AI-S ones myself and we could have met and you could try them; one does 1:2, the other I think does 1:1, only just discovered that one (long story).

I don't have close up lenses, so the pair of us are mutually useless ;) neither one has experience of the other's situation!

Don't suppose you're coming 'down south' soon?

Quote:

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Originally Posted by Dave Humphries

Hi Keith,

It's a shame you're quite so far away, I have recently acquired a couple of old AI-S ones myself and we could have met and you could try them; one does 1:2, the other I think does 1:1, only just discovered that one (long story).

I don't have close up lenses, so the pair of us are mutually useless ;) neither one has experience of the other's situation!

Don't suppose you're coming 'down south' soon?

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I'm afarid not Dave, but thanks for the offer.
I was just hoping someone may have used both.

I have just discovered that if I took a photo of a square approx 4 1/4 inch x 2 3/4inch at 200mm at a given distance it should fill the frame, therefore if I attach a close up filter and it records 1/4 of it at the same given distance then I assume it is 1:1.
Well thats about as genius as my brain gets at maths so I am probably way out,lol.

Dumb idea: take a picture of a ruler. If you can see 36mm x 24mm then you've got a 1:1 ratio (at least with full frame). Can it be that simple?

I will admit that I'm confused by what lens vendors mean by magnification factors on crop-fram sensors.

Quote:

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Originally Posted by BeardyGit

Dumb idea: take a picture of a ruler. If you can see 36mm x 24mm then you've got a 1:1 ratio (at least with full frame). Can it be that simple?

I will admit that I'm confused by what lens vendors mean by magnification factors on crop-fram sensors.

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I can see where you are coming from Beardygit (great name by the way), I guess I would have to subtract 25% from those dimensions for a cropped sensor.
I would imagine other factors come into the equation such as focusing distance and close up filter magnification rating.