Need help re: how to focus a camera

[sequoia 0]

I have chronically been unable to get a clean, crisp focus on my cameras. I have several camera type but have standardized on Bosch WDR LTC 0630 models. Usually with 5-50mm bosch lens.

 

I just today tried taking a camera down, placing it on a table, and hooking it up to a 20" TV/monitor directly without going through a DVR. I even got some reading glasses out to try to pin the focus down exactly. At the same distance (table vs. actual install), I tried the best I could to focus it perfectly but it is still not crisp as I have seen in some other photos posted here. It's a good picture, no arguing that, but just not perfectly focused.

 

This is not my first stab at this-- it seems I have trouble focusing all of my cameras, so maybe I need some special tricks on how to get a better focus. Do you have any suggestions?

 

(ps I have good vision.)

[SEANHAWG 1]

Sounds like a peculiar problem, you should definetely be able to get a nice sharp picture pretty easily which makes me think there is still some kind of problem causing the cam to be out of focus.

 

1) Did you test your camera on a Tube TV or LCD? For the most part, you will get a sharper picture on a tube.

2) Is the lens screwed on completely all the way?

3) That camera looks like a 1/2" CCD, are you using a 1/2" lens and not a different sized lens with an adapter?

4) When you say it doesnt look like some of the pictures on here, I just want to make sure you arent comparing it to megapixel images. Also, alot of the images on here are squeezed down from there original size which makes the pixels more condensed which results in a better image than it would up on a big monitor, but still it shouldnt be too much different

5) Whenever you bench tested it, did you get any focal points to appear sharp at all? Or was it just the particular focal point that you were trying to get that was not appearing sharp

[sequoia 0]

Thanks for the reply. Here's a couple of answers and hopefully a sample pic. In the sample pic I was trying to focus on the wrought iron fence. To assist with that, I put the white colored pot right in front of the gate/walkway and used it to focus on.

 

1. I was using an LCD TV. Maybe I will try a tube model next?

2. The lens is screwed tight to the camera. There was a silver camera ring supplied with the camera and the lens will fit with or without using it. Can't remember if it is installed on the cam or not-- not sure if this is critical.

3. This particular camera is the Bosch equivalent that is 1/3 ccd with a 1/3 lens.

4) Enclosed is a sample image from my DVR but the camera image looks the same even when connected without running through the DVR.

5) I cannot seem to get any focal points to appear sharp. When I move the focus ring ahead or behind the focal point it blurs in either direction but focuses down in-between, but I just cant get the image to be crisp no matter how carefully I fiddle with it?

 

When you focus, do you use any particular thing to focus on, like a sign with lettering, or use any special lighting or other tricks? I have one cam that I want to capture license plates after dark, and I am intending to re-visit that cam after dark and focus it then.

 

http://i807.photobucket.com/albums/yy360/californiabagman/Sample2.jpg

[tomcctv 187]

Thanks for the reply. Here's a couple of answers and hopefully a sample pic. In the sample pic I was trying to focus on the wrought iron fence. To assist with that, I put the white colored pot right in front of the gate/walkway and used it to focus on.

 

1. I was using an LCD TV. Maybe I will try a tube model next?

2. The lens is screwed tight to the camera. There was a silver camera ring supplied with the camera and the lens will fit with or without using it. Can't remember if it is installed on the cam or not-- not sure if this is critical.

3. This particular camera is the Bosch equivalent that is 1/3 ccd with a 1/3 lens.

4) Enclosed is a sample image from my DVR but the camera image looks the same even when connected without running through the DVR.

5) I cannot seem to get any focal points to appear sharp. When I move the focus ring ahead or behind the focal point it blurs in either direction but focuses down in-between, but I just cant get the image to be crisp no matter how carefully I fiddle with it?

 

When you focus, do you use any particular thing to focus on, like a sign with lettering, or use any special lighting or other tricks? I have one cam that I want to capture license plates after dark, and I am intending to re-visit that cam after dark and focus it then.

 

http://i807.photobucket.com/albums/yy360/californiabagman/Sample2.jpg

 

 

like SEANHAWG has said with a bosh and a 50m lens you should have no problems. but in your secound post you say EQUIVALENT to bosh. what make camera do you have ??? and also your lens is it glass or plastic

[sequoia 0]

Apologies for not being more clear. The camera is:

 

Bosch LTC0498 camera with LTC3674 Varifocal Lens IR corrected.

[tomcctv 187]

Apologies for not being more clear. The camera is:

 

Bosch LTC0498 camera with LTC3674 Varifocal Lens IR corrected.

 

 

that camera is just like the bosh pixim as well as focus on the lens you also have focus on the camera. you get it as best you can by the lens then you can fine focus with the blue ring on fron of camera.

 

[SEANHAWG 1]

2. The lens is screwed tight to the camera. There was a silver camera ring supplied with the camera and the lens will fit with or without using it. Can't remember if it is installed on the cam or not-- not sure if this is critical.

 

If the silver ring is on, try taking it off as it may be preventing the lens from getting close enough to the CCD sensor, causing the blurry image. The lens that you have is a CS-mount lens and the silver ring that is on the camera could possibly be a C-mount adapter. Try taking the silver ring off to see if you have better results.

[rory 0]

1-Never used the camera so take this as you will

2-Generally you need to backfocus it first, that is probably the blue ring. Open the IRIS all the way by using the IRIS level. Zoom the lens all the way to the max telephoto (T), then adjust the focus all the way to Infinity (like a sideways 8 ). Next adjust the backfocus until it is focused crisp. Make sure you are focusing on some letters or something you can get a fine focus of, such as a licence plate or some kind of grill or bars, but not too small that you cant see the edges clear. Once that is clear then set the Iris back to normal, adjust that outdoors in bright sun if you can, then adjust the zoom and focus to your required setting for the app or do that at the location. If the camera has a sharpness setting inside its OSD then set that to max before doing any of this. When in doubt check the camera manual and they should mention how to backfocus that camera, maybe even give diagrams.

[sequoia 0]

Thank you for the assistance.

 

I discovered that this camera had a computar lens on it (5-50mm.) Not sure if that was an issue, I changed it to the Bosch lens described above. No help. When I did this I confirmed that there is no adapter in place-- the lens screws directly to the camera body.

 

I set sharpness to max, went to max zoom and focus to infinity. I set the cam to backfocus mode which opened the iris, and did the backfocus. My, oh my what a crisp clear picture I got doing that.

 

Then, I locked the backfocus in place, and pulled back the zoom and refocused. Disappointment. Enclosed is the image and I simply cannot get something here that doesn't look blurry. It's a bit embarassing to not be able to accomplish such a simple thing?

 

http://s807.photobucket.com/albums/yy360/californiabagman/CCTV/

[rory 0]

make sure you readjust the iris back to normal.

[sequoia 0]

Yes, after fiddling with the backfocus I removed it from backfocus mode and the iris resets over the next couple of seconds. I also dialed down the sharpness a little.

 

I just unboxed one of my 1/2" Bosch cams, fitted a 1/2" lens, and got similar results. Maybe my expectations are too high, or maybe I need a tube TV to use for focusing. All I know if that when I pull back from max zoom I can no longer get a crisp focus???

[rory 0]

Max zoom is always going to be the sharpest, and the easiest to focus. If you want to focus more wide then get something closer to the lens otherwise it can be difficult. Also yes it can be difficult on an LCD anyway, though they vary. A small 13" TV for example should work great. BTW what are you using to focus on, an object or just the surroundings? Always focus on the center of the image also, then check the edges and adjust. And BTW some cameras and lenses just suck for focusing. I wouldnt expect a Bosch Box cam to be one of them though. Could also be bad lenses, or camera chips, though unlikely as you switched them. Make sure lens is clean as well, no finger prints. Are you focusing it inside or outside?

[sequoia 0]

Yes I have adopted those focus techniques. I am focusing outside.

 

Maybe the answer is the lens itself. I have bought 7.5-50mm lenses as they seemed more versatile, with a wider operating range, than 2.8-12mm lenses. But, if I'm focusing at the equivalent of 10mm and wanting a crisp picture it sounds like a 2.8-12mm lens would be far superior than what I have with the lens that goes up to 50mm.

 

Everything I have done on the other cameras, up to now, has been at max or nearly max zoom. So maybe I need to adjust a couple of lenses when I'm not even getting close to the 50mm limit?

[SEANHAWG 1]

I didnt think that the second picture that you posted was that bad, it doesnt look like you have very far to go. To me, it looks focused, but just not sharp. Was that picture taken over the network? if so that could also be the problem of a little fuzziness of the picture. I would bet that it would look sharper on the local monitor given that it was a small tube TV. Was that picture set at max sharpness?

 

Also, I want to make sure that you are focusing the camera at the location that the camera will be in, instead of focusing at your work bench and then setting the camera outside.

[sequoia 0]

The 2nd photo was taken over a network. Quality, in my opinion, is the same as when connected to a monitor directly.

 

When focusing, I set the camera to max sharpness (15 out of 15) but it makes the picture pretty grainy. After focusing, I reduced the sharpness to 10. I looked at the cam last night at the b/w night picture is still a little too grainy for me.

 

The camera is mounted on a side wall inside an enclosure. I'm setting up a work bench right beside the camera and am doing the focus outdoors in the identical conditions the camera is in during use.

 

I will pick up a 3.8-12mm lens today and see what kind of picture quality that generates in this situation.

[Soundy 1]

It's a common rule of thumb in the photography world, that "prime" (fixed focal length) lenses tend, in general, to be cleaner and sharper than zooms (notwithstanding the ultra-pricey high-end professional zooms), and that shorter-range zooms (like a 70-200mm, which is about a 3X factor) tend to produce better output than similar-grade long-range zooms (like a 28-300mm, or a 10X zoom factor). The larger the zoom, the more compromises that need to be made in the design to keep things compact and usable.

 

I haven't seen any real qualitative tests, but I would imagine the same holds true for CCTV lenses - larger zooms are more convenient and versatile, but I'd expect them to make the same sort of compromises of quality (unless you spend big bucks).

[SEANHAWG 1]

I'm setting up a work bench right beside the camera and am doing the focus outdoors in the identical conditions the camera is in during use.

 

If its a vari-focal lens that I am dealing with, I will get it focused as I am bench testing it to the approximate distance that it will be viewing in on, then I will always fine focus the camera once I get it installed. This can sometimes be a pain in the butt to do with just one person as you will be having to run back and forth to look at the monitor to see what it looks like (unless of course you have a CCTV video tester) but I always have to re-focus mine once I install them.

 

I just have a feeling that there is something else at play here. I know that Bosch 5-50mm lenses arent cheaply made and you should definetely be getting a nice sharp picture with it. I am not convinced that its your lens but I could be wrong.