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-   -   Kodak ZX5 auto focus (https://forums.steves-digicams.com/hybrid-still-movie-mp3-digicams-85/kodak-zx5-auto-focus-188622/)

pablouk Jun 4, 2011 8:52 AM

Kodak ZX5 auto focus
 
Hi My first post

Just purchased my new zx5 and iam a little bit disappointed by the auto focus. When i set the camera up on a tripod in the garden and record it seems that around the edges of the footage looks blurred, is this natural for the ZX5 or is it a faulty cam.

Will there ever be a switch to switch off the autofocus in future firmware updates?

UnknownVT Jun 4, 2011 1:46 PM

Quote:

Originally Posted by pablouk (Post 1231398)
Just purchased my new zx5 and iam a little bit disappointed by the auto focus. When i set the camera up on a tripod in the garden and record it seems that around the edges of the footage looks blurred, is this natural for the ZX5 or is it a faulty cam.
Will there ever be a switch to switch off the autofocus in future firmware updates?

First let us please check:

Is you video image sharp and in focus at the center of the frame?
or is it blurry and out of focus as the edges?

If it is sharp and in focus at the center - but edges are blurry - this is due to the quality of the lens -
most lenses are sharper in the center, than at the edges.

If the center is sharp, but from your description the edges sound pretty bad -
then there is probably some thing wrong with the lens itself -
and I would suggest getting a refund or replacement - asap -
there is nothing one can do to cure this.

However if it is not so sharp/clear and in focus in the center either -
then please read the below:

It's funny, on top-end camcorders AF (auto-focus) is obviously a mandatory feature.

However with a fixed focal length pocket camcorder - it may seem desirable, until one realizes that in filming a video - what we consider the main subject may move around a lot and the camcorder may not focus on that and choose something else (normally anything that's easy to lock focus on) -
whereas fixed focus lenses - which may seem primitive/low-tech have everything in focus from about 1 m or 40" to infinity - so as long as one's subject is more than 1m or 40" away, it is in focus - there is nothing to set - so nothing to go wrong (well, OK we could put our fingers over the lens! :p)

So you might want to test your Zx5's AF ability - put a well defined object isolated - ie: nothing around it and place its image bang in the middle of the Zx5 frame/screen from about 4ft away - film that and see on your computer is the object nice and sharp, and in focus.
Now try different distances, now at about 4ft vary the placement on the screen to the side(s) top and bottom and see if the Zx5 focuses on anything else. If it seems to keep the focus on the object - then examine the videos when the object is to the side - does it still look unsharp?

If all those test seem satisfactory then it might just be that one footage -
try to use what you just learned about how the Zx5 focuses to avoid any future problems.

If a few of those tests fails try to figure out what might be the limitation of the Zx5 and try to avoid those types of situations - if that's acceptable to you.

If the majority of them fail - then there may be something seriously WRONG with your Zx5 - again suggest getting a refund or exchange ASAP.

pablouk Jun 4, 2011 3:19 PM

Thanks for this advice i will try tomorrow when its light and let you know if its ok.

pablouk Jun 4, 2011 3:50 PM

Hi i decided to do the focus test tonight as i could not wait. please find enclosed the comparison videos it looks as if my thoughts were correct the camera struggles to focus on the left hand lower part of the lens


Please leave your thoughts after watching the sample checks

OK Focus http://www.youtube.com/watch?v=3XBHoG8WYwc

NG Focus http://www.youtube.com/watch?v=57a5mx8Cs7U

RH OK http://www.youtube.com/watch?v=QCRZ1KM8xUQ


please watch in full screen either 720 or 1080

fishycomics Jun 4, 2011 4:12 PM

Quote:

Originally Posted by pablouk (Post 1231482)
Hi i decided to do the focus test tonight as i could not wait. please find enclosed the comparison videos it looks as if my thoughts were correct the camera struggles to focus on the left hand lower part of the lens


Please leave your thoughts after watching the sample checks

OK Focus http://www.youtube.com/watch?v=3XBHoG8WYwc

NG Focus http://www.youtube.com/watch?v=57a5mx8Cs7U


please watch in full screen either 720 or 1080

Inside is focused. outside the red is out offocus, the other vid is not good. I suggest a replacement, you must have a full screen focal, but ask kodak they'll read you its normal.

If you are not getting Full focal range you got issues. to me that is not good at all. looks like your cam isstuck in a macro mode tpye .. and see if everything is set to a off. like water/h20 I am sure there are no settings on a kodak zx5 its a point-n-shoot

Best to ret a swap and see if the exchange is better?

http://img863.imageshack.us/img863/6522/image1uh.png

UnknownVT Jun 4, 2011 4:15 PM

Quote:

Originally Posted by pablouk (Post 1231482)
Hi i decided to do the focus test tonight as i could not wait. please find enclosed the comparison videos it looks as if my thoughts were correct the camera struggles to focus on the left hand lower part of the lens
Please leave your thoughts after watching the sample checks

OK Focus http://www.youtube.com/watch?v=3XBHoG8WYwc

NG Focus http://www.youtube.com/watch?v=57a5mx8Cs7U

Well you may have just proven something for yourself.

However, the first OK video is not conclusive -
as the wall/skirting board is close to the bottle - the focus could have been anywhere along the skirting board - the bottle has to really be isolated away from anything near the same distance, and the skirting board is not - so the Zx5 might or might not have focused on the bottle.

Second NG video might be showing some problem as you said - however it seems to me that the distance of the bottle is very close certainly closer than 4 ft might even be closer than 10cm or 4" which is the closest focusing distance for the Zx5 - so the Zx5 might be struggling to focus that close and failing that it focused on the next easiest thing the skirting board - hopefully now you can understand why the first OK video may not be as conclusive as you thought.

Since it was so easy for you to do the video -
try again this time set the bottle at least about 4ft from the skirting board - use a tape measure and film at about 4ft from the bottle - start with the bottle in the center - then move the Zx5 framing so that the bottle is at the sides of the frame like you did in the second video and see if the Zx5 does change its focus - by moving the bottle over all the sides/corners of the frame you should be able to see where and when the Zx5 goes out of focus. Don't forget the floor itself could be something the Zx5 could focus on - so might want to put the bottle on a stand or something off the floor.

We may know what we would want a camera to focus on - but a camera is not able to read our minds and may well focus on whatever is easiest.

Please try again and see.

BTW - watching the first OK video - it seems there is nothing wrong with the Zx5 lens - it seems acceptably sharp all the way to the left/right edges.

qv98 Jun 4, 2011 6:12 PM

i really hate they made these cameras with autofocus. the same is with the sony bloggies, they have focus hunting

pablouk Jun 5, 2011 8:51 AM

More Conclusive test
 
I have used the advice above and tried this test again. Can you guys have a look and let me know what you think.

If anyone has a zx5 can you please do the same test to try to identify if this is a firmware issue on all zx5s or if it is just mine that looks faulty.

Center - OK
http://www.youtube.com/watch?v=g-fppp1oCeM

Left - NG
http://www.youtube.com/watch?v=akm2X5hPbos

Right - OK but take ages to focus
http://www.youtube.com/watch?v=7fpb6Sag5UQ

Please leave me your thoughts and any further tests i may need to carry out.

Thanks for the advice so far

Edit: just found this video which looks as if it has the same focus problem http://www.youtube.com/watch?v=E29AX83PoFQ

UnknownVT Jun 5, 2011 11:49 AM

Quote:

Originally Posted by pablouk (Post 1231670)
I have used the advice above and tried this test again. Can you guys have a look and let me know what you think.
Center - OK
http://www.youtube.com/watch?v=g-fppp1oCeM

Left - NG
http://www.youtube.com/watch?v=akm2X5hPbos

Right - OK but take ages to focus
http://www.youtube.com/watch?v=7fpb6Sag5UQ

Edit: just found this video which looks as if it has the same focus problem http://www.youtube.com/watch?v=E29AX83PoFQ

Center OK now shows that the Zx5 does keep focus at the center.

Right OK shows hunting - focuses on bottle and shifts to skirting board.
Hence the remark from qv98:
Quote:

Originally Posted by qv98 (Post 1231530)
i really hate they made these cameras with autofocus. the same is with the sony bloggies, they have focus hunting

It appears that the Zx5 is designed to give more weight to object in the middle - which kind of makes sense - because the bottle is actually quite bit to the right and there is no way the Zx5 could have read your mind to know that is what you wanted the focus on.

In fact I would consider this Right OK to be worse than the Left NG - as the focus is shifting/hunting and it's very annoying.

Left NG - clearly shows that the bottle is not in focus -
Please look at Post #5 in this thread from our resident expert Fishycomics - where he showed the AF area on the Zx5 your Left NG the bottle is on the border of the AF area - and the camera chose to focus on the skirting board instead - hence the bottle is out of focus.

Let's just go back to you new center OK video -
it is very relevant to my remarks on your new Left NG video -
you may have missed it -
in the first 2 seconds of the Center OK your dog was on the left side of the frame -
would you have preferred the Zx5 to focus on your dog instead?
Probably not, otherwise you would have said something -
you considered the Center OK because the Zx5 maintained its focus on the bottle. Sorry, you can't have it both ways.

It's a limitation on the Zx5 - I don't think there is anything wrong with the AF par se - it may well have a slight bias toward the right in other words shift the red frame to the right in Fishy's illustration.

You should do more tests so you know where the AF limits are,
so that for your real videos you can make sure you avoid framing your main subject in such a way that the Zx5 would choose to focus on something else -
or put it another way try to frame your videos with your main subject toward the center.

Lastly I could not see much focus problems with the underwater reef tank video - seems pretty good to me - the left side occasionally is slightly out of focus - that's because the Zx5 is focused on central area and because it is close, so the depth of field is shallow - so the lens cannot have everything in focus -
this is a normal characteristic of lenses - nothing's wrong at all.

pablouk Jun 5, 2011 1:21 PM

Thanks for the reply Vincent

Maybe i am just expecting for a little to much from a 115 camera. After more tests the focus seems to be worse at 1080. the 720 60fps doesnt look to bad.

I think i will try a few more tests outdoors then make a decision to swap it for another just to be sure.

I think iam just being a bit to picky.

Do you think it would be ever possible to switch af on or off?

Anyway thanks for the great support on this topic.


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