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focusing in ultra-macro mode (especially focus bracketing)

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Offline PhyrePhoX

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focusing in ultra-macro mode (especially focus bracketing)
« on: 30 / April / 2008, 19:27:50 »
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Hi,

i have a raynox msn505 macrolens which i used to find out that ants have hairy armpits yesterday  :lol (well, i dont know if its true, but they do have a lot of facial hair, which i was able to see, also i could see their mouths gnawing on food.) basically half the regular ant is in the fov when u use this supermacro.
well anyways, in order to use this lens properly you have to set the zoom to the biggest setting, which is 12x in the case of my s3is. the dof already being paperthin (read the whole article here: Lensmateonline - Canon PowerShot S5/S3/S2 IS Macro ) it is VERY hard focusing. so today i wanted to test focusbracketing (for stacking), which worked ok without the lens (in widest setting) with a step size of 1 (1 millimeter).
however when at the full tele end (using the macrolens) , this doesnt work. only a small part of a coin was in focus, and it was always the same part. do i have to apply different values or is it better building a kind of dolly for either the subject or the camera (and using a fixed focus)?
i could close the aperture more (via overrides, hey i'm at long zoom range) but i get the feeling this doesnt increase dof either. anyways, i need a method to do focus bracketing/stacketing.

attached is a sample picture of a chip from an old motherboard. it is out of focus, because i couldnt keep my hands steady with that shallow dof (obviously i will have to use a fixed position later). the other two pics have been shot using normal macro mode (without the extra lens and without zooming) and the last one is without macromode, just a wideangle shot from the motherboard. all shots are 100% crops.
« Last Edit: 02 / May / 2008, 08:32:46 by PhyrePhoX »

Re: focusing in ultra-macro mode (especially focus bracketing)
« Reply #1 on: 30 / April / 2008, 23:44:34 »
If you are using 72mm (432mm) FL, the step size will not be 1mm, you apply the step size in meters. This is because the lens focus from infinity to about 800 mm nearest at 72mm. So the steps has to be meters. To start with you can set the focus to somewhere near 30m at 72mm FL and step size to 1 or 2 m. You may fine tune the steps as per the results obtained.

With lens at 6mm FL at super macro, the step size of 1mm works as the lens has the focus range from 0mm to about 100mm.

Re: focusing in ultra-macro mode (especially focus bracketing)
« Reply #2 on: 01 / May / 2008, 00:21:29 »
After checking at Raynox site I realized that it is a super macro attachment. At 72mm FL it focuses at 17mm if set at infinity. At closest focusing it may focus at 5-6mm. So the whole range will not exceed 10-11mm. Your steps may have to be larger than 2m.

You may try any 50mm normal SLR lens reverse mounted on s3is to obtain similar results as MSN-505.

From Raynox site:
MSN-505 Super Macro/Close-Up lens
With MSN-500 Super Macro lens attached, the camera captures an intricate tiny object like 2.5mm x 1.9mm for a frame-filling enlarged close-up image from the distance of 17mm to the object at the maximum telephoto position.You can simply "Snap On" MSN-500 Super Macro lens onto the lens holder by using a universal mount UAC3500 and it will be able to take macro images with minimum distortion at the maximum telephoto position of PowerShot S5 IS/S3 IS/S2 IS camera.
RB52S2 lens holder adapter or Canon LAH-DC20 is required for use with the S2IS camera.
Magnification : 8.8X compare to original super macro image size.
Lens construction : 3G/4E Optical coated glass elements.
Front filter size : None
Rear threads size : 37mm
Size/Weight : MSN-500 42 x 24mm/86g.

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Offline PhyrePhoX

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Re: focusing in ultra-macro mode (especially focus bracketing)
« Reply #3 on: 02 / May / 2008, 08:35:29 »
thanks for your input. with steps as large as 2 meters, this won't work i guess, as the camera has a focus range of 0 cm to 5m and then to infinity, right (roughly)? gonna test it anyways. if it doesnt work i have to build myself a dolly. wanted to do that anyways, because i wanna write a "Vertigo Script" for that special effect... :D


 

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