:: View topic - Rotifer darkfield test movies in DivX mode
 Forum Index
An online community devoted to the practices of photomacrography and amateur microscopy..
 
New! Photomacrography2.net
 
This site is no longer available for posting or registering new members.
 FAQFAQ   SearchSearch     UsergroupsUsergroups   
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
Rotifer darkfield test movies in DivX mode

 
This forum is locked: you cannot post, reply to, or edit topics.   This topic is locked: you cannot edit posts or make replies.     Forum Index -> Macro and Micro Technique and Technical Discussions
View previous topic :: View next topic  
Author Message
Thomas Ashcraft



Joined: 31 May 2006
Posts: 25

PostPosted: Tue Jun 27, 2006 7:17 am    Post subject: Rotifer darkfield test movies in DivX mode Reply with quote

I have posted some short test movies of Rotifer activities shot in darkfield with a Meiji microscope and a Logitech quickcam 4000 camera.

http://www.heliotown.com/Rotifer_Movies_divx.html

I think my Meiji optics are quite fine but my darkfield movies seem to me to be a little soft for my own tastes. I am wondering if there are better movie making tools out there for short specimen movies shot in darkfield?

I am also testing out DivX compression as a sharing mode for the internet.

Any advice and/or stern critique is most welcome as I am hoping to document the microlife here in the high desert of New Mexico in best quality.

Thanks! - Tom
Back to top
View user's profile Send private message
rjlittlefield



Joined: 06 May 2005
Posts: 727
Location: Richland, WA, USA

PostPosted: Tue Jun 27, 2006 10:32 pm    Post subject: Reply with quote

Thomas,

I looked at all your movies. The sharpness seems OK to me, but the movies are pretty dark and I think this is degrading the detail that I can see. I paused several places, pulled still frames into Photoshop, and discovered that they were using only about 1/2 of the brightness range. For example, to my eye, still frames from Rotifer_contracting28sec are much improved with a Levels adjustment of (14,1.00,147). I don't know cheap software to make this correction after capture. Does your setup allow to adjust brightness and contrast during the capture?

My gut feeling is that DivX is close to the best you can do for videos intended to be generally accessible. It certainly has a good reputation. In very brief testing, Microsoft WMV seemed to give me good quality with better compression, but Wim reminded me that not all computers can read it, even with plugins.

--Rik
_________________
Reworks and reposts of my images in this forum are always welcome, as are constructive critiques.
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Thomas Ashcraft



Joined: 31 May 2006
Posts: 25

PostPosted: Wed Jun 28, 2006 6:18 am    Post subject: Reply with quote

Rik wrote:

I looked at all your movies. The sharpness seems OK to me, but the movies are pretty dark and I think this is degrading the detail that I can see. ........ I don't know cheap software to make this correction after capture. Does your setup allow to adjust brightness and contrast during the capture?

My gut feeling is that DivX is close to the best you can do for videos intended to be generally accessible.

--Rik

Hi Rik,

Thanks for the feedback. It's really helpful!

I am using a Logitech quickcam pro 4000 camera ( $70.) and exploring its capabilities in both Windows and Mac. The camera settings are variable ( brightess, red, blue, gamma, etc.) and it is a challenge to get the balances right per microscope mode and particular microscopic scene.

Once the movie is shot I am processing it in the Mac's I-movie software and have actually been darkening them somewhat to enhance contrast. This might be artificial and esthetic on my part and may compromise some information in the scene. This is why your feedback is good for me to hear.

Regarding DivX : The compression is pretty good but their proprietary movie player and aggressive marketing gives me the creeps. I think there will be better compression modes in the near future since this seems to be a real need.

Again, thank you for your feedback. I will consider it well.

Tom
Back to top
View user's profile Send private message
rjlittlefield



Joined: 06 May 2005
Posts: 727
Location: Richland, WA, USA

PostPosted: Wed Jun 28, 2006 7:45 am    Post subject: Reply with quote

Thomas,

Thanks for the additional info. Now I understand better.

I agree completely about DivX. New and better video compressors seem to come out every year or so. There's no reason to think that this year and next will both be exceptions.

Maybe you would be happy thinking in terms of "master" and "display" versions of your movies. For stills, I usually shoot raw, process and edit to a full-resolution Photoshop stack, then shrink, sharpen, and post a low-resolution JPEG. All three files get saved. If need arises, I can regenerate from the Photoshop or even go clear back to the raw.

Have you considered archiving versions of your movies in a less-compressed format?

About the brightness, part of the issue is Mac vs PC. The standard monitor "gammas" are different. Images that look fine on a PC look washed out on a Mac, and images that look fine on a Mac look dark on a PC.

In still images, this problem is being addressed gradually by color management software. The concept is to put "color profiles" into image files, each profile being just a table that tells how to interpret pixel values as colors in a standard way.

But color management seems to be slow getting into video formats and players. Unfortunately you may have to just pick a target and go for it.

See http://www.siggraph.org/education/materials/HyperGraph/color/gamma_correction/gamma.web.html for discussion. Google search on macintosh pc gamma monitor will get you lots more.

--Rik
_________________
Reworks and reposts of my images in this forum are always welcome, as are constructive critiques.
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Display posts from previous:   
This forum is locked: you cannot post, reply to, or edit topics.   This topic is locked: you cannot edit posts or make replies.     Forum Index -> Macro and Micro Technique and Technical Discussions All times are GMT - 7 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB 2.0.6 © 2001, 2002 phpBB Group