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Author Topic: shooting with 150mm macro+extension rings on rail or refocus ?  (Read 2470 times)
guido.coza
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« on: May 30, 2014, 03:49:05 PM »
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Hi All
what I have is a 150mm macro lens, 3 extension tubes (+/- 50mm) a macro rail and a canon dslr!
Until now I did macro stacks with eos utility, LR5 and PS5
I put my subject on a table/ leaf/stick, position the camera on a tripod with macrorail more or less in focal range and than focus one with the rail to get a proper mid-focus on the object. Now I use the canon software to remote control focus and shutter actuation.I go into lupe view and focus on 200%take the shots,  Import with LR. than EDIT in PS "open as layers, >auto align, > auto blend layers and flatten. This pic was over 6GB large, but the results is at best, OK

As the picture shows, the eyes are not clear and crisp and the whole pic is sort of soft! This picture is stacked from 72 single raw files, the fly is about 6mm and the pic is not cropped! Nearly brought my MBA down )-:
My question and the problem I see is now. How can I get a 100% in focus and sharp picture? If I move the camera or the subject on the rail, how do I know the amount of movement I need and how can I control 0,5mm. Also The camera would shake to much if I had to move on the rail wheel.
Any Ideas tips.
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elf
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« Reply #1 on: May 30, 2014, 06:28:22 PM »
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www.photomicrography.net would be the best place for macro advice. 

When focus stacking, you should determine which aperture is sharpest for your lens, then calculate the focus depth and number of steps required.
http://en.wikipedia.org/wiki/Depth_of_field has the formula (Look for the 'Close-up' section) for the focus depth.

Most macro rails aren't capable of making multiple small steps accurately.  You can make it a little better by putting a larger dial on the rail wheel.

Try adding 20 or 30 pounds of weight to the tripod (if it can handle it).

Use the EFSC if your Canon supports it.

Diffused flash may give you better subject lighting.
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guido.coza
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« Reply #2 on: May 31, 2014, 03:16:51 AM »
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Hi elf
Thanks for the tips
The aperture was set to 6,3 the best being 8, purely to give me a better shutter speed.
I will try the weight, but with the mirror lock-up and  the remote cable, i hoped I would have eliminated all possible vibration sources.
BTW what does EFSC stand for?
Ones again a big thank you
Guido
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elf
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« Reply #3 on: May 31, 2014, 12:12:35 PM »
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EFSC is Electronic First Shutter Curtain which means the shutter opening is electronic. Shutter closing is mechanical, but these vibrations shouldn't affect the image.

My desktop macro setup is firmly attached to an 80 pound block of granite and it is still affected by the shutter vibrations.  One simple way to see the vibrations is to balance a shot glass of water on top of the camera when shooting.
 
Here are a couple of sites that may be of interest:
http://www.cambridgeincolour.com/tutorials/macro-lenses.htm
http://extreme-macro.co.uk/
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bab
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« Reply #4 on: May 31, 2014, 11:08:19 PM »
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The only way is to move the lens internally and wait for shutter vibrations to stop oscillating back off your camera and reduce the extention tubes. Also the plane of focus falling off the sides of the eyes is slippery and your stacking software gets confused down and around the corners. Also you can shoot at f8 or f11 and get the same results unless your pixel peeping.
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Fine_Art
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« Reply #5 on: June 03, 2014, 09:13:32 PM »
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At first I am impressed by the amount of detail in the shot. Focus stacking seems to be the way to go. Then I notice the black fuzzy outline around the subject. Is that from the OOF shots? does the software mask whit it decides to keep or do you have to go through manually masking everything?
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BartvanderWolf
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« Reply #6 on: June 04, 2014, 07:15:57 AM »
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At first I am impressed by the amount of detail in the shot. Focus stacking seems to be the way to go. Then I notice the black fuzzy outline around the subject. Is that from the OOF shots?

Hi Arthur,

Yes, in a way it is related to the OOF shots, but also to the fact that at close distance , the lens (e.g. left side rays versus right side rays will see from a different perspective point) can look a bit around edges. It's actually also an artifact from the stacking method that was used, and Photoshop doesn't offer any choices. Dedicated Focus Stacking applications (such as Helicon Focus and Zerene Stacker) offer a choice between roughly two or three methods (weighted averaging, depth map, and pyramids), and one can mix results afterwards. Some are better for maintaining structural/surface detail, others will suppress edge artifacts better.

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does the software mask whit it decides to keep or do you have to go through manually masking everything?

It's mostly an automatic process, although dedicated stackers offer radius settings and may offer Retouch options (including (masked) output layers) for cases that are difficult to achieve automatically.

Cheers,
Bart
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