Critique my image
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Critique my image
This is my first real stack and I have a few questions for those knowledgeable folks out there willing to critique. Images were shot at 3x, 1.3 second, f/2.8 at ISO 100. This is the first time I have used this lens.
1. How to I configure the 50D for higher resolution images. The stack was 72 PPI? I always shoot RAW but I was under the impression that Zerene only accepts .JPG and .TIF.
2. Lighting suggestions?
3. Image doesn't seem to be as sharp as it could be?
Thanks in advance,
-JW:
1. How to I configure the 50D for higher resolution images. The stack was 72 PPI? I always shoot RAW but I was under the impression that Zerene only accepts .JPG and .TIF.
2. Lighting suggestions?
3. Image doesn't seem to be as sharp as it could be?
Thanks in advance,
-JW:
- rjlittlefield
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Re: Critique my image
The PPI issue has nothing to do with pixel counts or resolution. It's just that Zerene Stacker has removed the PPI spec along with all other metadata, and then your image viewer turned "no PPI specified" into "72 PPI" by plugging in its own default value. See further explanation at http://zerenesystems.com/cms/stacker/do ... nly_72_dpi , and consider selecting Options > Preferences > Image Saving > "Copy metadata from source images to saved output images".
Regarding sharpness, the two main factors are usually vibration and aperture.
About vibration, shooting with continuous light can work well if you're in a very quiet environment and you're shooting with EFSC (electronic first shutter curtain). If either of those is not true, then you'll get sharper images from flash. It's especially good to use consumer flashes cranked down to low power so the light pulses are very short. I recommend shooting a test stack illuminated by flash even if you're pretty sure that your environment is quiet. If the result ends up sharper, then you'll know that at least part of your problem is vibration.
About aperture, that's always a tradeoff between diffraction and aberrations. Variation between lens units can factor in also. It seems that some MP-E 65 lenses are best wide open, but some are better stopped down a little. You have to test to know what's best with your particular equipment.
Without seeing the actual specimen, it's hard to say much about the illumination. Over most of the area it appears to be OK, but then I don't understand those crystals at top center that look very much brighter than the rest. Can you show us a shapshot of your overall setup, including lights and diffusers?
--Rik
Regarding sharpness, the two main factors are usually vibration and aperture.
About vibration, shooting with continuous light can work well if you're in a very quiet environment and you're shooting with EFSC (electronic first shutter curtain). If either of those is not true, then you'll get sharper images from flash. It's especially good to use consumer flashes cranked down to low power so the light pulses are very short. I recommend shooting a test stack illuminated by flash even if you're pretty sure that your environment is quiet. If the result ends up sharper, then you'll know that at least part of your problem is vibration.
About aperture, that's always a tradeoff between diffraction and aberrations. Variation between lens units can factor in also. It seems that some MP-E 65 lenses are best wide open, but some are better stopped down a little. You have to test to know what's best with your particular equipment.
Without seeing the actual specimen, it's hard to say much about the illumination. Over most of the area it appears to be OK, but then I don't understand those crystals at top center that look very much brighter than the rest. Can you show us a shapshot of your overall setup, including lights and diffusers?
--Rik
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It's hard to believe vibration is an issue BUT it could be that I didn't wait long enough before pressing the remote. There were many occasions where I cranked the table and the camera hadn't recycled when I pushed the remote.
The picture below was my exact setup, including the "single" light that is on. No other light sources were used (excuse the mess). Suggestions welcome.
I have a old 580EX Canon Speedlite that I'm not familiar with operational wise (feature wise) will that work? If so, is there some sort of mount available for it or should I simply mount it on the camera shoe (if it fits the 50D).
Below is an untouched image, not cropped, just resized to 1280, no Photoshop etc.
The picture below was my exact setup, including the "single" light that is on. No other light sources were used (excuse the mess). Suggestions welcome.
I have a old 580EX Canon Speedlite that I'm not familiar with operational wise (feature wise) will that work? If so, is there some sort of mount available for it or should I simply mount it on the camera shoe (if it fits the 50D).
Below is an untouched image, not cropped, just resized to 1280, no Photoshop etc.
- Charles Krebs
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The 50D is one of the best cameras DSLRs as far as vibration is concerned (as long as you are sure to set it to "Silent Mode" in the live-view menu). Settle time after shutter re-cocking and moving the stage is important. It can vary greatly with each set-up. Just play around while carefully observing a fine detail on the LCD screen magnified 10X. Tap the camera, the base, the lens, and see how long it takes for the jiggling of the focused detail to "settle down". This can provide a pretty good idea of the pause needed between shots. (It can also sometimes show if you have an environmental vibration problem not related to your set-up).
At 3X I would also try a stack at f4. With a subject like you show here with these fine "needles", the smallest aperture you can use while still getting the resolution you want will give an easier stack. f4 will give you an effective f16 at 3X so I would not go smaller, but I suspect you will find it a slightly easier image to do compared to wide-open.
(Be cautious of the FO illuminator if you use that. I've had some where the fans caused enough vibration to be a real concern. and unless you check carefully for it you would never notice it).
At 3X I would also try a stack at f4. With a subject like you show here with these fine "needles", the smallest aperture you can use while still getting the resolution you want will give an easier stack. f4 will give you an effective f16 at 3X so I would not go smaller, but I suspect you will find it a slightly easier image to do compared to wide-open.
(Be cautious of the FO illuminator if you use that. I've had some where the fans caused enough vibration to be a real concern. and unless you check carefully for it you would never notice it).
Excuse me if you're NOT new to stacking software & Zerene, but pyramidal methods like PMax tend to make the highlights "glow".
Try a DMap stack, with experimentation to get the Estimation & Smoothing parameter about right (See the ZS website for guidance) then you'll probably find it best to retouch the Pmax image in a few places, with DMap.
DMap probably won't be good all over for this subject, but it's still very useful.
If vibration is an issue, you could try putting the heavy metal stages on a common slab, with something squishy underneath.
It CAN be amazing how much the floor moves.
Try a DMap stack, with experimentation to get the Estimation & Smoothing parameter about right (See the ZS website for guidance) then you'll probably find it best to retouch the Pmax image in a few places, with DMap.
DMap probably won't be good all over for this subject, but it's still very useful.
If vibration is an issue, you could try putting the heavy metal stages on a common slab, with something squishy underneath.
It CAN be amazing how much the floor moves.
Chris R
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- Posts: 1954
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- Posts: 1954
- Joined: Sat Oct 07, 2006 10:16 am
- Location: Bigfork, Montana
- Contact:
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- Posts: 1954
- Joined: Sat Oct 07, 2006 10:16 am
- Location: Bigfork, Montana
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Cabbage Looper egg(?)
My daughters garden has these little puppies all over the stems on one of her plants. I wonder if they are Cabbage Looper eggs? Looks like some little creature is inside of one of these to me. Actually I haven't a clue what they are. She said they are secretions from the Okra plant.
I struggled with the lighting and over exposed areas. Not sure how to eliminate those issues at the time of imaging. Oh, BTW that's a sewing needle with the egg stuck to it.
I struggled with the lighting and over exposed areas. Not sure how to eliminate those issues at the time of imaging. Oh, BTW that's a sewing needle with the egg stuck to it.
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- Posts: 1954
- Joined: Sat Oct 07, 2006 10:16 am
- Location: Bigfork, Montana
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- Posts: 1954
- Joined: Sat Oct 07, 2006 10:16 am
- Location: Bigfork, Montana
- Contact:
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- Posts: 1954
- Joined: Sat Oct 07, 2006 10:16 am
- Location: Bigfork, Montana
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Different angle. This is with the 50D's on-board camera flash enabled, black construction paper in the background with the object surrounded by a few sheets of white printing paper. I probably should of closed the blinds on the window. You can see the glare from it on the left and the reason for the white paper. Guess I could of done a little sharpening on that puppy too.
BTW, I'm all ears for any suggestions on what to purchase for a couple of remote flashes that will work with this particular camera. Also suggestions how how to mount the flashes, magnetic base seems appropriate with some sort of adjustable articulating arm. If you have something that you've personally used and liked, a brand, part numbers, or links would be greatly appreciated.
Regards,
-JW:
BTW, I'm all ears for any suggestions on what to purchase for a couple of remote flashes that will work with this particular camera. Also suggestions how how to mount the flashes, magnetic base seems appropriate with some sort of adjustable articulating arm. If you have something that you've personally used and liked, a brand, part numbers, or links would be greatly appreciated.
Regards,
-JW:
- rjlittlefield
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- Posts: 1954
- Joined: Sat Oct 07, 2006 10:16 am
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Thanks,
I tried a few late last night with another larger Cabbage Looper. This is probably the best one I took. That's its mouth. Dunno what the diamonds are inside his mouth. The composition sucks but I didn't know how else to mount it with the setup equipment I currently have and limited experience.
I also tried taking an "overall" of this puppy with my Cannon 100mm Micro. I didn't have a clue what the settings should be, how many images to stack or how to get the full width in focus. I'm not even sure if the lens is capable of sharpness at the corners. Have any suggestions on how I should of approached the over all image? It was only about 10 images, f/8, with the camera flash and .005 steps.
-JW:
I tried a few late last night with another larger Cabbage Looper. This is probably the best one I took. That's its mouth. Dunno what the diamonds are inside his mouth. The composition sucks but I didn't know how else to mount it with the setup equipment I currently have and limited experience.
I also tried taking an "overall" of this puppy with my Cannon 100mm Micro. I didn't have a clue what the settings should be, how many images to stack or how to get the full width in focus. I'm not even sure if the lens is capable of sharpness at the corners. Have any suggestions on how I should of approached the over all image? It was only about 10 images, f/8, with the camera flash and .005 steps.
-JW:
Nice and very interesting pictures of a Lime Hawk-Moth larvae (Mimas tiliae), almost sure.
The "white diamonds" in the mouth are just the openings between the triangular teeth of the two jaws. Perfect for sawing through heavy leaf tissue. An eating machine. Never seen this before.
Looks scaring in this magnification.
Troels
The "white diamonds" in the mouth are just the openings between the triangular teeth of the two jaws. Perfect for sawing through heavy leaf tissue. An eating machine. Never seen this before.
Looks scaring in this magnification.
Troels
Troels Holm, biologist (retired), environmentalist, amateur photographer.
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