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Old Feb 17, 2006, 1:25 PM   #1
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I'm looking for a 55-28mm step down ring for my FZ30.
Does anyone know if they exist?

If not, i'd use 2 or 3 rings.. 55-37mm and 37-28mm....(or whatever combinations i need to get to 28mm)
Whats a good place to buy step down rings?
Is the thread pitch a standard 0.75mm?

thanks
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Old Feb 17, 2006, 8:27 PM   #2
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A 55 - 28 step down ring probably does not exist, at least as a single unit. You'll probably need several stacked. Most likely problem will be severe vignetting due to the number of rings used and the extremely small add-on lens. Threads are common. Check withPemaraal On-line to see if they have anything that might fit your needs. ( http://www.pemaraal.com/index.html ) I have used Pemaraal for several purchases and found them to be very responsive to any questions I had.

Hope this helps at least a little.

Paul in NoVA
Oly E- 500 C- 730
http://www.flickr.com/photos/stoney_g/sets/
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Old Feb 17, 2006, 9:12 PM   #3
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Thanks plq3,

Everyone is telling me the vignettign will be harsh...
The reason i need to step my FZ30 down to 28mm, is because I have a Nikon 995 (28mm) and a Nikon microscope. There is a 28mm adapter that lets me attach the 995 to the microscope and take pictures of the samples under the microscope. I dont need a large FOV, so i though it still might work....
Only one way to find out!

thanks again for you help, i'll check out that website. I prefer using all the same brand, as opposited to several brands.

plg3 wrote:
Quote:
A 55 - 28 step down ring probably does not exist, at least as a single unit. You'll probably need several stacked. Most likely problem will be severe vignetting due to the number of rings used and the extremely small add-on lens. Threads are common. Check withPemaraal On-line to see if they have anything that might fit your needs. ( http://www.pemaraal.com/index.html ) I have used Pemaraal for several purchases and found them to be very responsive to any questions I had.

Hope this helps at least a little.

Paul in NoVA
Oly E- 500 C- 730
http://www.flickr.com/photos/stoney_g/sets/
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Old Mar 1, 2006, 3:27 PM   #4
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Hi LEICA,

I think not only would there be severe vignetting problem because several step rings are used, it may also be attributed to the mega-zoom of your FZ30.

I have been researching on digiscoping (attaching digital cameras to telescopes) recently, and also came across photomicrography in my web searches. These two activities are very similar because you are shooting through eyepieces (a high magnifying lens of small diameter). It seems that point-&-shoot cameras with small zooms (eg. 3X) do much better than mega-zoom cameras, because most mega-zoom cameras have terrible problem of focusing through the eyepiece at the high tele-zoom setting. This is identical to the situation when people try to "stack" too many tele-converters onto a mega-zoom camera, and the result is you cannot focus at all.

Yes you can pull back on the zoom to a wider view, but say for the FZ30 with a 55mm lens diameter, pulling back means severe vignetting because only the (relatively) small central portion of the camera field catches the diameter of the eyepiece (20-30mm I think??) only at the high tele-zoom end.

This is why the Coolpix 900 series is so well adapted to telescopes and microscopes - 28mm lens matches the field diameter of the eyepieces; threads to allow direct attachment and minimizing the distance from the eyepiece; a relatively weak zoom with little focusing problem.
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Old Mar 1, 2006, 5:14 PM   #5
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Thank you Blindsight,

I guess I will hold back on using the FZ30 on the microscope.

Maybe one day a high end 28mm will pop-up

Thanks for your help!
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