MACRO LENS WHat IS THIS??

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mashmosh
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Joined: Oct 13 2000

I AM VERY NEW TO VIDEO MAKING I HAVE ACCESS TO MY UNIVERSITIES CAMCORDERS, I WANT TO MAKE A VIDEO, USING A MAQUETTE SIZE LANDSCAPE , I WANT THIS LANDSCAPE TO APPEAR REAL SIZE THOUGH, A FRIEND MENTIONED I COULD USE A MACRO LENS TO CREATE THIS EFFECT, COULD ANYONE ELABORATE A BIT MORE ON THIS AND POSSIBLY GIVE ME SOME ADVICE,

tom hardwick
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Joined: Apr 8 1999

The term macro has been pilfered from the Swiss firm Bolex and is now used by a variety of lens makers to say simply that their lenses are able to focus very close up. In 35mm terms it meant a 1:1 up to about a 1:4 ratio, ie the object would be the same size on the negative to 1/4 size on the negative.

Modern DV cameras get nowhere near this, but very nearly all of them allow objects that actually touch the front element glass to be filmed in sharp focus. This is often (incorrectly) referred to as macro focusing.

I suggest you start experimenting with your camera on a tripod and having a +3 diopter closeup lens screwed into its filter thread. You'll be able to zoom and focus and most importantly light your subject without shadowing it with the camera.

If you have more questions (you will) then do come back. And keep experimenting; it's a long road.

tom.

ddmurphy
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Joined: Mar 21 1999

mashmosh

Please switch off your capslock and do not make your topic in capitals. It is considered rude in bulletin boards and Bob does not like...He will come and bite you!

David

rbarry
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Joined: Mar 27 1999

I found this old message from a search for "macro", as I need advice on a close up/macro lens. I posted the following on the DVi community sony vx2000/2100 forum, ( http://www.dvinfo.net/conf/showthread.php?s=&threadid=30830 )and as yet have had no reply:

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Having owned my "nearly new" vx2000 for 3 weeks now, and added a telephoto converter and wide-angle lens, I would like to ask members advice about the macro capabilities of this cam.
Without a macro lens, what is the best technique of filming close up objects, and how close can you get before losing focus. Do you choose the widest angle and get in close or do you zoom. If a macro lens is the best answer, what lens have you got and at what price?
Thanks in anticipation,

Rick
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and a follow up..............

Giant bee causes eclipse !!
Having spent some time yesterday trying close ups of flowers and insects, it would appear that the widest angle setting allows the largest images of the subject matter to be captured. however, the drawback is that you have to get so close to the subject that the lens is practically touching the bee/flower/caterpillar and causes unwanted interference with the subject, coupled with the reduction in light due to the close proximity of the subject and its' surroundings to the lens. Would a macro lens allow for an even closer view but maintain a greater physical distance from the subject matter ?
Any one here have any experience of using a macro filter with the vx2000/2100 ?
many thanks
Rick

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From Tom's reply it would seem that I need a "diopter closeup lens", that would change the point of focus away from the lens, which is what I hoped would be the case. Are these available with a 58mm thread to suit the vx2000, and if so can you recommend a brand and also what diopter rating/combination should I be looking at for good image enlargement ?

Thanks for bearing with me!!!!

Rick.

tom hardwick
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Joined: Apr 8 1999

Rick, pop out to your nearest Jessops and have a rummage in their 'left-overs' bin. There's often close-up lenses in there as people wonder what to do with them.

But if you buy new, I'd suggest you get something powerful like a +3 dioptre. www.srb-film.co.uk (I think it is) have a good selection, and 58mm fittings are very common.
Not really necessary to buy coated versions I find, as the type of work will mean you can select smallish apertures and use good lens hoods.

tom.

Christian Lett
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Joined: Apr 26 1999

I bought a Jessops close-up lens for £12, which I recently used on a shoot, very successfully. It allowed me some creativity as the background is thrown out of focus when you're focused on your near-subject, but I could rack-focus to the background quite easily.

Just remember to keep the lens clean! Any dust or scratches will show up on the video when your focused close-up.

Christian.

Christian Lett After Effects and Maya Artist www.quarterlightpictures.com

rbarry
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Joined: Mar 27 1999

Tom and Christian, thanks for the prompt replies and advice. Is there a correlation of the diopter number rating of the close up lens, that can be used to ascertain the point of focus from the lens of my vx2000, when used at different zoom levels from wide angle to extreme telephoto. I presume that the greatest magnification of a subject relies on the closest physical proximity from the camera that remains in focus at the extreme end of zoom magnification, which is x12 for the vx2000. If I understand this correctly, is this example correct:
Using say a +2 diopter lens the point of focus at extreme zoom was 3 meters from the camera, would a +3 diopter lens bring the point of focus closer to the camera, thus allowing a larger image to be captured as the camera would have to be moved closer to the subject, say 2 meters ? I am not using these distances as gospel, but merely as a way of illustrating my question. If the two lenses were threaded together, might I expect a closer still proximity to the subject to enlarge it even more, say 1 meter ?

Forgive me if I'm being pedantic, but I would like to understand the mechanics of using a macro/close up lens/lenses.

Many thanks
Rick

rfolwell
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Joined: Apr 10 2004
Quote:
Originally posted by tom hardwick:
www.srb-film.co.uk (I think it is) have a good selection, and 58mm fittings are very common.

Actually it is www.srbfilm.co.uk

A very useful link indeed. Thank you for that.

Richard

Alan McKeown
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Joined: May 9 2001

If the close up lens has a focal length of f metres
the power of the lens in dioptres (D) is 1/f

So a lens with a power of 2 dioptres has a focal length of 500 mm

If we place the close-up lens at a distance equal to its focal length away from the object we wish to focus on, then the light rays from the object will exit the lens parallel to one another.

We can now set the camera lens (without the close-up lens) to focus on infinity.

Combining these two, the close up lens and the camera focussed on infinity gives a combination which allows the object (at distance 1/D metres from the close-up lens) to be in focus at the camera imaging plane.

Alan

rbarry
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Joined: Mar 27 1999

Thankyou Alan, I think I follow that.

PaulD
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Joined: Aug 31 2002
Quote:
Originally posted by rbarry:
....Is there a correlation of the diopter number rating of the close up lens, that can be used to ascertain the point of focus from the lens...

Hi
A diopter is the reciprocal of the focal length of the lens in metres (D=1/f).
So if you focus your camera on infinity, and attach a 1 diopter lens without disturbing the focus, then an object at 1 metre distance will now be sharp.
A 3 diopter lens will reduce the point of focus nearer to 33cm.

Once you start to use your cameras focus ring you will make the sharp-point distance even closer to the lens.

The zoom factor of the lens doesn't come into this equation when talking about screw-on close-up lens attachments - unless your lens has a special inbuilt 'macro' mode which only works at certain zoom settings without any attachment.

(I was writing this whilst the previous posts were being added...)

rbarry
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Joined: Mar 27 1999
Quote:
Originally posted by PaulD:

quote:Originally posted by rbarry:
....Is there a correlation of the diopter number rating of the close up lens, that can be used to ascertain the point of focus from the lens...

Hi
A diopter is the reciprocal of the focal length of the lens in metres (D=1/f).
So if you focus your camera on infinity, and attach a 1 diopter lens without disturbing the focus, then an object at 1 metre distance will now be sharp.
A 3 diopter lens will reduce the point of focus nearer to 33cm.

Once you start to use your cameras focus ring you will make the sharp-point distance even closer to the lens.

The zoom factor of the lens doesn't come into this equation when talking about screw-on close-up lens attachments - unless your lens has a special inbuilt 'macro' mode which only works at certain zoom settings without any attachment.

(This last paragraph wasn't visible in your reply, but was if I hit the "reply with quote", very strange.)

Paul, thanks for the information. Is it not then possible to use the zoom on the vx2000 to capture a larger viewable image of the subject, and so maintain an acceptable distance away from it.

PaulD
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Joined: Aug 31 2002

Hi
Of course - I just meant the focus distance the diopter supplementary lens gives is independent of zoom setting, so the field of view can be varied by using the zoom control - as normally.

rbarry
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Joined: Mar 27 1999

Thankyou Paul, and all the others that were kind enough to reply.