Fluke TIR trouble

[Gary T. Heller]

On todays inspection My camera would not focus. I changed the palette to black and white and it didn't make any difference. Anyone else experience this with the Fluke? The camera is about 10 months old.

[Andrew MacDonald]

Gary,
I'm sure you tried this but in case you didn't.. Remove battery for a few minutes, reinstall and try and reboot.

[John McKenna]

Gary,

Were you in a poor delta T environment?

[Gary T. Heller]

Yes, on the last two inspections when this problem first showed up, indoor and outdoor temps were the same. Does that have an adverse affect on focusing?

[ldapkus]

Time for some training.

[Jason Kaylor]

As Linas stated, training will help.

A minimal delta T makes it harder to focus. Changing palettes like you did can help, going in to picture in picture mode can also help because it will give you a point of reference. Span and back ground temp can also help. Training will help you hone your skills with all of those features.

John has really good training focused towards home inspections. Infraspection, Snell and FLIR ICT are all great level I programs. I know a lot of guys that are super busy and just do not have the time to take off for training. I believe McKenna's training can be done online and I know Infraspection offers a distant learning program for the level I and II certs.

Jason Kaylor – JJ
VP of Sales
877/207-1244
AC Tool Supply
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[Kevin Luce]

Jason, I know that you are a sales person but do you go out in the field to do IR inspection on a weekly basis?

Just wondering.

[kweiss]

Poor thermal days will produce washed out unfocused images. Good reason to hate spring and fall.

I have noticed that this is more noticeable with lower resolution cameras. It usually isn't unworkable, but it makes the scan much harder to perform.

[Jeff Moore]

It's not that you are not able to focus with a small delta t but that without thermal differences it is difficult to tell if focus is right.
Thats where thermal tuning of the image is important and may necessitate
palatte change.
Remember that without a difference between outside and inside temps
a good thermal review of the home is extremely difficult.
imho

[John McKenna]

Originally Posted by gheller

Yes, on the last two inspections when this problem first showed up, indoor and outdoor temps were the same. Does that have an adverse affect on focusing?

This is probably the issue. Things look much more clear when
the temperature difference in various materials is very distinct.

When the indoor and outdoor temperature are all the same, then
many of the materials start to fog together as one temperature.
We call this a low delta T environment and it makes the image
look very poor.

The two cups below are very easy to see (and focus) because they
have such differences in temperature (high delta T). The stairs
disappear in the IR image because of lack of temperature difference.

Call me if I can help,

888-818-4838

[OJ Utter]

Gary-
One trick that helps with focus is changing to "black and white" color pallette. Also if you are looking at something like a wall with little thermal difference go put your hand on the wall for about 5 seconds. That gives you something to set your focus off of. But then you need to remember that when you change your distance your focus needs to change.

OJ Utter
www.utterprecision.com

[Gary T. Heller]

As always, thanks to all for the great info. I plan on getting the training but I want a bit more hands on with the camera first. (and a bit more money)

[William J. Decker]

Originally Posted by gheller

Yes, on the last two inspections when this problem first showed up, indoor and outdoor temps were the same. Does that have an adverse affect on focusing?

With low delta T, there is very little difference (if any) between the temp of different areas. No difference in temp, therefore nothing to focus.

When you focus a regular camera, you are relying on light intensity (and, to a certain extent, color) differences. If you try to focus a regular camera on a plain white wall, it is very hard. If you try to focus a camera in a dark room, it is hard, if not impossible.

Same thing with IR, but it is not the differences in light intensity of color, but the difference in temperature that is the problem.

I, usually, will not do an image with anything less than a 5 degree (F) delta T. Most people say 10 degrees, minimum. Depends upon your level of expertise and training. Have to set thinks like emisivity, reflectivity, leval and span to get any kind of meaningful image.

And, just because the image has something to focus does not mean that the inage in meaningful. It's NOT about the picture, it's all about the information that the image is containing.

Hope this helps;

[kweiss]

I have always found B&W to be the easiest to work with for most general applications in a home. Another trick for focusing is to focus on a window blind or HVAC register to gauge your distance focus. I use the hand trick to impress clients and there kids - hadn't really thought of using it for focus, but it would work.

[John Snell]

Originally Posted by gheller

On todays inspection My camera would not focus. I changed the palette to black and white and it didn't make any difference. Anyone else experience this with the Fluke? The camera is about 10 months old.

Gary,
In these situations with low thermal contrast, make sure your span is as narrow as possible. Then focus on something—ANYTHING!—with some thermal difference: a handprint, a lightbulb, sun shining on the floor. You need a thermal difference to be able to focus.

I would also encourage you to get some of your practice while NOT on the job. Job pressures are too great and make learning difficult (or dangerous!). Sit in your own home or office and try focusing in similar situations until you master the camera. You'll not regret the time invested. When you are ready, I hope you'll also consider more formal training.

Thermally yours,

John Snell
ASNT NDT Thermal/Infrared Level III #48166
Snell Infrared
800-636-9820
802-229-9820
http://www.thesnellgroup.com
http://www.IRTalk.com
http://www.learnnewsolutions.com/