Thanks to specious reasons for the identification.
Rashid
testate amoeba (thanks to specious reasons for ID)
Moderators: rjlittlefield, ChrisR, Chris S., Pau
testate amoeba (thanks to specious reasons for ID)
I got some water from a pothole in our backyard that usually has water after rain (I've been helping it a bit). There were lots of little roundish things scampering all over. too fast to try to see, let alone photograph. But I found this animal that was moving slowly. Photos are taken with 40x/0.65 Olympus achromat, 5x projection lens, E-P1 camera. Left: about 80% of full aperture; right: I closed aperture further. Post processing of jpeg file: adjusted light levels, reduced size, sharpened. I will be most appreciative of any critique and suggestions.
Thanks to specious reasons for the identification.
Rashid
Thanks to specious reasons for the identification.
Rashid
Last edited by xys on Thu May 05, 2011 10:28 am, edited 2 times in total.
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specious_reasons
- Posts: 107
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Because you are asking for sugestions...
The color balance is way off. To correct it the best way is to shot RAW and adjust it in post processing or to preset a custom WB if your camera allows it. You can also correct it later in PS, but the first options may deliver better results.
Your images are a good exemple of the ethernal brightfield dilemma: open diaphragm delivers more resolution but less DOF and contrast and closed diaphragm just does the opposed. The traditional equilibrium point between contrast an resolution is to close it to reduce at 2/3 the aperture as you did in the first one.
Oblique illumination is a good and inexpensive technique to increase contrast without losing much resolution.
The color balance is way off. To correct it the best way is to shot RAW and adjust it in post processing or to preset a custom WB if your camera allows it. You can also correct it later in PS, but the first options may deliver better results.
Your images are a good exemple of the ethernal brightfield dilemma: open diaphragm delivers more resolution but less DOF and contrast and closed diaphragm just does the opposed. The traditional equilibrium point between contrast an resolution is to close it to reduce at 2/3 the aperture as you did in the first one.
Oblique illumination is a good and inexpensive technique to increase contrast without losing much resolution.
Pau
Pau,
Many thanks for your helpful comments. In fact, I've tried to set custom balance and then take the pictures at the same light intensity, and I've tried correcting WB in raw, but I've not been very successful either way. I also tried correcting color balance in Elements (by clicking to get gray background), and that also is not easy, as it depends on exactly where I click, and I could not get a good background (other than converting to black-&-white). One problem is my extreme ignorance as to what I should expect. For example, I don't know if the brown center of the amoeba should in fact be brown, gray, or some other color
Thank you again for taking the time to give helpful comments.
Rashid
Many thanks for your helpful comments. In fact, I've tried to set custom balance and then take the pictures at the same light intensity, and I've tried correcting WB in raw, but I've not been very successful either way. I also tried correcting color balance in Elements (by clicking to get gray background), and that also is not easy, as it depends on exactly where I click, and I could not get a good background (other than converting to black-&-white). One problem is my extreme ignorance as to what I should expect. For example, I don't know if the brown center of the amoeba should in fact be brown, gray, or some other color
Thank you again for taking the time to give helpful comments.
Rashid
About the color balance, this thread has some useful info (but referred to a DIC setup)
http://www.photomacrography.net/forum/v ... highlight=
If you agree, I can repost your pictures with some simple color adjustements I've tested.
http://www.photomacrography.net/forum/v ... highlight=
If you agree, I can repost your pictures with some simple color adjustements I've tested.
Pau
Pau,
Many thanks for the link. I've read it quickly, but need to read all the posts in it more carefully. I have tried the dropper tool (in Elements-- I don't have Photoshop) to get a grey background, but, as one of the posts says, it depends on which pixel you use it on, and you get very different colors by clicking on different pixels in the same small area. But I'll pursue this some more (and try again using RAW also). Your offer to actually try to fix the colors is very generous. I certainly don't mind, and I will be very grateful if you do, but I worry about imposing too much, as you have already spent a lot of time trying to help me improve my images.
Thank you again,
Rashid
Many thanks for the link. I've read it quickly, but need to read all the posts in it more carefully. I have tried the dropper tool (in Elements-- I don't have Photoshop) to get a grey background, but, as one of the posts says, it depends on which pixel you use it on, and you get very different colors by clicking on different pixels in the same small area. But I'll pursue this some more (and try again using RAW also). Your offer to actually try to fix the colors is very generous. I certainly don't mind, and I will be very grateful if you do, but I worry about imposing too much, as you have already spent a lot of time trying to help me improve my images.
Thank you again,
Rashid
Pau,
After reading the link you provided, I saw that Mitch said that the eyedropper in Camera Raw works better (I learned something here, as I didn't even realize that there was one in Camera Raw). So I opened the raw file (I had set the camera to save both raw and jpeg) and, after selecting "tungsten", and adjusting exposure, and black level, I used the eyedropper, and I think it worked far better. I'm including the processed image to ask if that is OK now or still needs improvement.
Many thanks.
Rashid
After reading the link you provided, I saw that Mitch said that the eyedropper in Camera Raw works better (I learned something here, as I didn't even realize that there was one in Camera Raw). So I opened the raw file (I had set the camera to save both raw and jpeg) and, after selecting "tungsten", and adjusting exposure, and black level, I used the eyedropper, and I think it worked far better. I'm including the processed image to ask if that is OK now or still needs improvement.
Many thanks.
Rashid
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Charles Krebs
- Posts: 5865
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- Location: Issaquah, WA USA
- Contact:
Rashid,
Much better color balance! The "eyedropper" in PS Elements should yield similar results on the initial jpg you posted. I'm not sure why it did not. (In Photoshop you can adjust the eyedropper "sample size". If you can so the same in PS Elements set it for something larger than "point".... 3x3 or 5x5 pixels will be better for this.
While the color is much better the contrast is very low. A simple levels adjustment takes care of that. Here are some screen captures from Photoshop.
This first shows the histogram of this last shot you posted:
This second shows the "levels" adjustment settings and the result.
This not only increases the contrast in the amoeba (for the better), but also accentuates the mottled background (for the worse). By using layers or selections/masking you can easily apply the adjustment only to the area you want. This is seen below (I also touched up the upper right corner a little):
Much better color balance! The "eyedropper" in PS Elements should yield similar results on the initial jpg you posted. I'm not sure why it did not. (In Photoshop you can adjust the eyedropper "sample size". If you can so the same in PS Elements set it for something larger than "point".... 3x3 or 5x5 pixels will be better for this.
While the color is much better the contrast is very low. A simple levels adjustment takes care of that. Here are some screen captures from Photoshop.
This first shows the histogram of this last shot you posted:
This second shows the "levels" adjustment settings and the result.
This not only increases the contrast in the amoeba (for the better), but also accentuates the mottled background (for the worse). By using layers or selections/masking you can easily apply the adjustment only to the area you want. This is seen below (I also touched up the upper right corner a little):
Charles,
Many thanks for your comments and suggestions, and for taking the time to actually correct the image and provide a tutorial as well! I think I have a much better idea now what the image should look like and how to get there. As far as the grey eyedropper, it appears that there is no provision to change the area it samples ("point sample") in Elements (I just tried right-clicking on the tool and got a message "there are no options for this tool").
Again, thank you for your very helpful reply.
Rashid
Many thanks for your comments and suggestions, and for taking the time to actually correct the image and provide a tutorial as well! I think I have a much better idea now what the image should look like and how to get there. As far as the grey eyedropper, it appears that there is no provision to change the area it samples ("point sample") in Elements (I just tried right-clicking on the tool and got a message "there are no options for this tool").
Again, thank you for your very helpful reply.
Rashid
my magnum opus
Thanks to the wonderful help I got from specious reasons (for the ID), and from Pau and Charles Krebs for their excellent and painstaking help in obtaining good color and contrast, I'm posting a reworked image of the one I got at ~80% NA (the one on the left in the original post). I must admit, I like it much better than the original. I hope I did not fail my teachers too badly. As always, comments and suggestions for further improvement (on any aspect) will be much appreciated.
Thanks again!
Rashid
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Charles Krebs
- Posts: 5865
- Joined: Tue Aug 01, 2006 8:02 pm
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- Contact:
Rashid,
I know that in PS Elements you can adjust the sample size with the eyedropper tool that is on the regular toolbar ("point", 3x3 pixels, or 5x5 pixels) . I think whatever sample is set for that one might carry over and be used for the sample size in the "remove color cast" function. You might want to try setting the toolbar eyedropper size to 3x3 or 5x5 and then go back to the "remove color cast" function and try it on the first jpg you posted to see if it then does a better job.
I know that in PS Elements you can adjust the sample size with the eyedropper tool that is on the regular toolbar ("point", 3x3 pixels, or 5x5 pixels) . I think whatever sample is set for that one might carry over and be used for the sample size in the "remove color cast" function. You might want to try setting the toolbar eyedropper size to 3x3 or 5x5 and then go back to the "remove color cast" function and try it on the first jpg you posted to see if it then does a better job.
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rjlittlefield
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Charles, you are absolutely right. I never noticed that you could change the sampling area. And once set the size for the dropper in the main toolbar, it sets it also, as you had expected, for both the droppers in "levels" and the one in "remove color cast". Thank you very much!
Rik, many thanks! I had excellent teachers, though
Thanks to all,
Rashid
Rik, many thanks! I had excellent teachers, though
Thanks to all,
Rashid