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Old Dec 7, 2004, 7:27 PM   #1
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I'm thinking about getting an FZ20 + the Nikon 5T + 6T.
I have a few Q's, namely how the closeup lenses affect
(a) the depth of field
(b) effective lens focal length
(c) f-stop
at the various zoom settings

I have a little bit of optics background but not much & just know that diopters add reciprocally (e.g. if the FZ20 focuses at a point 0.5meter away == +2 diopters, and you add the 6T lens which is +3 diopters, then your total diopter is +5 == 0.2 meter away... at least I think that's how it works) -- but the other stuff is beyond me. Does it depend on how long the adapter is (e.g. short tube vs. long tube), and if so, how do you figure that stuff out??? The Lens FAQ (http://www.photo.net/photo/optics/lensFAQ.html ) has some guidance but doesn't deal with diopters at all. I'm an engineer so don't be afraid to post complicated equations.

Alternatively maybe those of you with FZ20 macro experience could tell me how close you can focus with the 6T / 5T / both, and what the depth-of-field tradeoffs are....
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Old Dec 7, 2004, 8:11 PM   #2
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well i am in the same boat you are in...whem i comes to the tech end of it i am not much help..i just picked up a nikon 6T but iam not sure how the get the most out of it "yet"I have seen where people are zooming 12x and being kinda close to the object there shooting...but when i try it my fz20 will not [email protected] 12x unless i back off 2 feet...how these guys are getting macros of a"fly's eye"is beyond me..i you find out please tell me..for its really "bugging" me no "pun" intended....

btw...mzmacro is the "macro king" look for ANY thing he might post or comment on..he is the man. :G

i can say this for the fz20 its a great camera...good luck.

Willow

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Old Dec 7, 2004, 9:13 PM   #3
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Did a quick search and came across this website on computing magnification
http://azone.clubsnap.org/insectguide/page02.html (thanks to Hector Niam)

".....you can do a some calculations to find out magnification factor before deciding which close-up filter/lens to purchase. The formula goes like this:

magnification factor = f / ( 1000 / d )

where
f is the maximum focal length of the camera,
d is the diopter rating of the close-up filter/lens....."

So for FZ, with a maximum focal length of 420 mm. If you are getting a +4 close-up filter, your magnification factor will be:
magnification factor = 420 / ( 1000 / 4 ) = 1.68

For close up filters, you can stack a them together and you can just add up the numbers e.g. +4 and a +2 = +6. Trade-off is distortion at the edges, and reduced DOF, so you will have to be more steady in your shots.

http://azone.clubsnap.org/insectguide/page02.html
"..............Theoretically, close-up filters and macro lens have a fixed focusing distance (depending on the diopter rating), regardless of what camera you use. How do we know calculate this distance? Mathematically, you can calculate this by dividing 1 metre by the diopter rating and you'll get the focusing distance (in metre).
Take for example I have a +4 close-up filter, my focusing distance should be:
focusing distance = 1 metre / d = 1 metre / 4 = 0.25 metre
where
d is the diopter rating of the close-up filter or macro lens.

But in practice, the actual distance may not be exactly as calculated. For example, when a +4 filter is used on the S602, instead of a focusing distance of 25cm, I get approximately 22cm. With a +2 filter, I'm getting around 35cm instead of the supposedly 50cm (1m divided by 2 = 50cm). You can conduct a quick check by switching to manual focus mode (with the close-up filter mounted on), zoom all the way up, then move the camera to and fro until you see the subject sharp in focus in the LCD. That should be the approximate distance you can focus at.......................... "

Hope this help, and hope I am correct.....anyone pls correct me if I am wrong....


I have not experimented with all the zoom range, but I think that the greater the zoom the shallower the DOF, thus I usually use F8 for taking pics.

I have a 6T on the FZ10 and the focus distance at 12x is 29cm. I also have a +1.6 Sigma Achromatic close up and have a distance of 40cm. Together is 19cm.



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Old Dec 8, 2004, 1:12 AM   #4
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tchuanye....thx for the headache lol jk man thats why i could pull back to about 20 or 25 cm and bingo crisp focus!!! how is nzmacro"Danny" getting soooo close on them fly's??? come on man hes got the whole friggin eye in the frame he said he does not crop any thing.....is he like stacking 3 or 4 of these dang things or what???????

Ihave a nack for this stuff i just need to know how to do it lol....

heeeeeelp meeee !!!!!!!

Willow

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Old Dec 8, 2004, 1:27 AM   #5
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I think is the SLR lenses that he uses in front of the FZ10, that gives him the HIGH MAGNIFICATION. This allows the eye to fill the frame. If you stack a couple of close up lens, such magnification can also be achieved, or by using a reverse lens, that can be achieved also. By using 6T alone, may not be enough.

For me....I use the cheap method.....cropping:-)! and with 6T + sigma of course

Like this I posted before...but the quality may not be as good as Danny's shots...


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Old Dec 8, 2004, 12:39 PM   #6
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Quote:
I have a 6T on the FZ10 and the focus distance at 12x is 29cm. I also have a +1.6 Sigma Achromatic close up and have a distance of 40cm. Together is 19cm.
Thanks tchuanye, that gives me a rough idea of what to expect; the image captured with the FZ10+6T at 12x must be about 2cm in extent, right? (29cm/12?) how much depth of field? is it only a few mm?

Would anyone out there mind posting a few test pictures with an FZ10/FZ20 + 6T? These would be of slightly boring subjects (see below) No big hurry, I just want to get an idea if the 6T is enough or whether I'm going to want the 5T also.

Here's what I'd do if I had the camera already:
* find a cereal box (or anything freestanding vertically)
* tape a US $1 bill (or anything with sharp detail, back side of the $1 bill has lots of engraving stuff) to the lower part of the box
* put a ruler in front of the box
* stand at a side angle to the box, so it's not head-on but rather about 30 degrees, and focus on the center of the $1 bill (the left and right edges of the bill will probably be out of focus due to depth of field issues, but that's the point, to measure it)

do this at minimum f-stop (f/8?) with the 6T lens on, with 1x zoom, 12x zoom and one or two points in between.
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Old Dec 8, 2004, 8:03 PM   #7
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You can see them here, taken by ddsm:

(edited: oops missed out the link sorry! here it is.....)

http://ddsm.smugmug.com/gallery/150921


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Old Dec 8, 2004, 9:26 PM   #8
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This may not answer your question directly but I'll post it nevertheless. From a thread at http://forums.dpreview.com/forums/re...ssage=10898770 The screens' interstices measure close to a mmand these are probably taken at close to 30 deg.



A boxelder bug on a backdoor screen with the raynox dcr250 [+8] and oly b-macro (+3) stacked (total +11 diopter) on the fz1v2. The bug is about an inch long; camera is about 4 inches away. Handheld and resized only (except for the last). Notice how the depth of field is so much shallower at full zoom. With the fz20 you should be able to crop the 5x shot and get pretty close to the quality of the fz1 12x shot and keep the greater depth of field. The last image is the the 5x cropped to the approx size of the 12x. The depth of field is better but hardly worth it.

At 5x zoom; iso50, 1/80s, f8, ev -2/3





At 12x zoom; iso50, 1/60s, f8, ev -2/3





Cropped 5x to area of 12x


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Old Dec 8, 2004, 9:59 PM   #9
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While were at it, here is another view (same set-up) at
Shutter Speed:1/40.00
Aperture:f/8.00
Exposure Bias:-0.66
Focal Length (mm):31.20
ISO Speed:50


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