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Old Apr 26, 2010, 01:25 PM
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Cumbria in the U.K
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Keychain camera focusing

First off I owe a big debt of gratitude to "quailbird"
He responded to one of my posts with a method for focusing a keychain camera.

This method is simple and brilliantly effective.... in fact it's simply brilliant

I had adjusted my keychain camera by twisting the lens in about 1/4 turn. This gave a noticeable improvement but I thought there may be more to be had, Then quailbird posted his method......

I tried again today....
I took 3 photos of the house and garden as reference material.

First I turned the lens in (clockwise) by a bit less than 1/4 turn. I then marked the lens and its holder with a spot of white paint. White emulsion 'cos it dries quickly , applied with the point of a cocktail stick.... one of those things you spear harmless little sausages on. (That meant the lens had been adjusted inwards about 1/2 turn from its original position when delivered).

I took another 3 photos of the same views as the first ones.

Transferred the photos from camera to computer. The ones I had taken after the lens adjustment were not good and .... here is the really clever part of quailbirds method... they were a SMALLER file size than the first 3.

Obviously the extra adjustment to the lens was no good. I backed it off a small amount and took the 3 photos again. This time when compared on the computer they were a bit sharper and the file size was BIGGER, but still smaller than the original 3 reference photos.

Obviously going in the right direction then.
A further small adjustment and 3 more test photos. This time the photos were much better and the file size was bigger than the original reference photos. This looked promising and a couple of test videos decided me to leave well alone.

Typical example...
Test reference photo - properties show a size of 423.6KB
Final focus adjutment a size of 493.2KB

Second reference photo 357.5KB
After final focus adjustment 455.9KB

There is a big gain in the amount of KB from before to after focus adjustment. Obviously more information is being packed in as the lens resolves more detail.

The sheer beauty of this method is the fact that there is an easy way to determine whereabouts you are with focus adjustments. If the file size of a test photo is increasing then you are improving the focus.... stop when you reach the maximum.... brilliantly simple.

Going for a walk this afternoon I took the camera and took some video footage around a local village. Putting the videos on my computer I was amazed at how good they were. As delivered these little keychain cameras are not bad, but adjust the focus and there is a BIG difference in the video quality.There is a belting little camera hidden in there if it is tweaked a bit.

I may have been able to improve it a bit more if I had adjusted it a bit more but I am well satisfied with the results now and didn't think it worth the effort to do more fiddling.

In a nutshell...
Put spot of white paint on both lens rim and lens holder.
Take reference photos.
Adjust lens.
Take reference photos again and compare both sets on the computer.
If file size is bigger then you are heading the right way.
Repeat untill satisfied.

Done.... welcome to your, now, much sharper focusing camera.

Brilliant method quailbird.
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Old Apr 26, 2010, 02:40 PM
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Good post Sparklet
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Old Apr 26, 2010, 02:42 PM
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Rich Hill Missouri 64779
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Way to go Sparklet! I can't wait to see some pictures. I've been too lazy...er...busy to do both my key chains but now I'll have to.
BTW! A long time ago I saw this method on the forum and I used it for the Aiptek pen cameras and it worked for all the small cameras. I'll pass the praise to someone else, I just can't remember who it was.
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Old Apr 27, 2010, 08:12 AM
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Thanks for sharing this procedure. I too would love to see the before and after pictures.
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Old Apr 27, 2010, 09:28 AM
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Cumbria in the U.K
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Hi Guys,
I will post some video later when I have got it sorted.
Just come back from a quick flight.
I will stick them up under a new thread title and they should be online tonight.
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Old May 06, 2010, 04:42 PM
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Of course you could just put it in webcam mode and use your computer monitor to adjust the focus in real time. See http://chucklohr.com/ for details on how to do this. It's so much easier and precise.
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Old May 06, 2010, 04:59 PM
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I'd go with the webcam method myself, making sure to adjust focus on very distant object outsides, not close in, like inside a house, etc.

I've not tried the file size method, but have one caveat. Your reference photo needs to be oriented with pretty much the exact same image each time. The camera's JPEG video compression algorithm acts on the captured image, so a different image can easily change the compressed file size, whether you change focus or not.
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Old May 07, 2010, 03:35 PM
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Thanks for the comments Tom.
I take your point - but - I run Linux and I don't know if there is a driver available to use the keychain camera as a webcam.
A lot of these drivers are for Windows only - Linux Gurus usually "back engineer" suitable drivers for stuff but there would need to be reasonable demand for it.
I could search around but it might take longer to find something than using the file size method !

From my other post, with before and after videos, it can be seen that refocusing made a BIG difference to the performance of the camera.
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Old May 07, 2010, 10:10 PM
Oh so close!
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Would really like before and after photos please! Has anyone else posted before and after yet?

cheers
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Old May 08, 2010, 01:52 PM
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Quote:
Originally Posted by clipper99 View Post
Would really like before and after photos please! Has anyone else posted before and after yet?

cheers
I put up some video that I shot just before and after adjusting the focus.
I will see if I can pull it back to the "top of the heap" again.

Look out for the post and I think you will be surprised at the marked difference that can easily be seen in the two video clips.
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Old May 09, 2010, 10:36 AM
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I reckon, in order to save a bit of confusion, I will stick the before and after video on here as well as my other post.

First part of the video shows the performance of my "mark-3" keychain camera before I refocused it.

Second part of the video shows the improvement after refocusing.

http://vimeo.com/11268206
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Old May 09, 2010, 11:21 AM
Oh so close!
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Quote:
Originally Posted by sparklet View Post
I reckon, in order to save a bit of confusion, I will stick the before and after video on here as well as my other post.

First part of the video shows the performance of my "mark-3" keychain camera before I refocused it.

Second part of the video shows the improvement after refocusing.

http://vimeo.com/11268206
Well, I guess I know what I'm doing at some point today! WOW! Huge improvement.

Thank you for posting.
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Old May 09, 2010, 01:18 PM
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Quote:
Originally Posted by clipper99 View Post
Well, I guess I know what I'm doing at some point today! WOW! Huge improvement.

Thank you for posting.
Hi,
Glad you found the video.
Quite a difference in quality from just a bit of messing about. I was amazed when I shot some video of our grandchildren and found out just how good the camera is now.
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