How Can a Fixed-Focus Camera Be Out of Focus?!?!?

[dvarapala 0]

And only partially out of focus at that!

 

I bought a (relatively) cheap Vivotek FD8134V to watch the side gate to my back yard. All was fine at first, but after a week or so I noticed that the image was blurry (except for the plants to the right, which are closer to the lens).

 

 

This blurring (near-sightedness?) only happens during part of the day; at other times the focus is much better:

 

 

The camera is mounted in a spot where it's in full sun during the morning hours; this period roughly corresponds to the time when the focus is most blurred. Presumably the sun is heating up the lens or other interior components, causing them to expand and shift the lens relative the image sensor.

 

Am I asking too much of this camera to have it operate in direct sunlight? Note that the sun does not shine directly into the lens, so the picture is never washed out by glare. My Axis dome was in full afternoon sun for over a year with no issues.

[Soundy 1]

It's entirely possible for this to happen. If it's a standard M12 lens, the focus isn't actually fixed; the lens threads into the lens mount and focus is adjusted by turning the entire lens, moving it closer to or farther from the sensor. In most cases, the lens will be pre-focused at the factory, then locked in place with a small setscrew, although a few designs use a spring around the lens barrel to maintain tension on it.

 

In your case, it looks like the lens mount itself might be loose, and one corner of it is pulling away from the camera board when it heats up, thus moving one side of the lens away from the sensor. Or it could just be some "play" in the lens threads allowing it to move with the temp changes (especially if it IS spring-loaded).

[3RDIGLBL 0]

I've installed a number of these and have had to send back two so far. One camera was taking down my POE switch, power non Poe and switch worked fine but turn on Poe to that camera and switch shutdown. New camera was fine. My second camera had focus issues. The camera was an interior 8134 and one side of the picture could never come into focus. I would turn the small lens and the left side would be clear but the right was blurry and vice-versa. New camera fixed that one as well.

 

I would say this one would have to be returned.

[SEANHAWG 1]

But why is it focused during some parts of the day and not others. His 2nd image looks really sharp.

[Soundy 1]

But why is it focused during some parts of the day and not others. His 2nd image looks really sharp.

Read my second paragraph above.

 

It's also possible that the lens element itself is just cheap plastic heat changes are affecting its shape.

 

Really, lots of THEORETICAL reasons for it... only way to know for sure is to disassemble and inspect the camera. Or... just send it back.

[SEANHAWG 1]

aww, I see. Could be so.

[MaxIcon 0]

My Messoa shifts focus as I tighten down the lens screws, and there's enough slop in the threads that it was hard to get it focused in the first place, as focus would shift when I let go of the lens. Add that it required removing the IR board to access the screws, and I've got a few new lenses on the way to try out, and it turned into a big pain.

 

I ended up putting teflon tape on the lens threads, which both holds it in place securely without the screws, and keeps the lens stable by getting rid of the thread slop. Dunno if that would help with your Vivotek, but it's an easy fix to try.

[camera-newbie 0]

My Messoa shifts focus as I tighten down the lens screws, and there's enough slop in the threads that it was hard to get it focused in the first place, as focus would shift when I let go of the lens. Add that it required removing the IR board to access the screws, and I've got a few new lenses on the way to try out, and it turned into a big pain.

 

Yikes! That would be a major pain if installing a bunch of cameras that behaved like that!

[3RDIGLBL 0]

Why is it as a business owner and installer that I feel like a guinea pig for these big camera companies? I run into so many money losing issues I wonder why I keep doing this at times!

 

Then you call and they say it's you until you spend more time feeding back the info until they say "OH YA!" we'll send you a new one or a new lens or a new this or that. You keep installing them and keep running into the same crap!

 

Got issues with Vivotek with IR Reflection. Just did another install yesterday and the same issues...I got a number of new lenses from them to replace the 10 or so cameras I have with this issue. Where's my free camera or my pay check to fix their crap.

 

Signed the frustrated one!

[dvarapala 0]

Follow-up: I finally got an opportunity to climb up on a ladder and pull the cover off this thing. Nothing obviously loose or broken, so down it comes and back it goes. I'll let y'all know about my experiences with Vivotek warranty service.

[buellwinkle 0]

What I've done with Mobotix in the past is have them connect to your camera and see for themselves. This way there's no question when you send it in for repairs that the problem exists. Last thing you want is to send it in and have it come back the same.