Dust map

Shooting in macro mode, techniques, tips & tricks

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Borberg
Posts: 4
Joined: 19.02.2005 19:09

Dust map

Unread post by Borberg » 19.02.2005 19:20

No matter how carefully you clean your lenses and chip there will be residual dust left, plus the drying rings from the cleaning fluid (I use Eclipse from Photo Solutions).
When you use a macro lens with 1:5 magnification and view the image on a 21" monitor (320 mm high), you have a viewing magnification of 5x320/24 = 66x. At this magnification a speck of dust in diameter of a human hair will be about 3 mm.
If you shoot a series of pictures (e.g. 10) and adjust the focal point each time to focus on another depth of the subject, the picture size changes, but the dust remains in the same position. The result is a string of 10 dust "beads" and if you have dozens of dust spots (that's a clean lens!) the picture looks awful.

Fortunately Helicon Focus has a dust map function which cleans up this problem. I use it with great success. Keeps me from having to clean the lens more often than desirable as this is a very delicate task.

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Dan Kozub
Posts: 355
Joined: 24.03.2004 18:14

Unread post by Dan Kozub » 06.03.2005 12:26

Peter,

can you post your dust map to the forum? It would be interesting to see how dirty the optics can be :)

Dan

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Dan Kozub
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Joined: 24.03.2004 18:14

Unread post by Dan Kozub » 07.03.2005 22:49

Peter,

1. The white frame (25%)
2. bottom left corner of it (100%)
3. dust map, generated by Helicon Focus (25%)
Attachments
dustmap_amplified.jpg
dustmap_amplified.jpg (43.05 KiB) Viewed 39168 times
dustmap_bottom_left_corner.jpg
dustmap_bottom_left_corner.jpg (23.92 KiB) Viewed 39168 times
dustmap.jpg
dustmap.jpg (23.98 KiB) Viewed 39168 times

kentel
Posts: 4
Joined: 31.05.2005 13:50
Location: UK

Unread post by kentel » 27.06.2005 14:57

Can you please tell me, how do you make a dust map using HeliconFocus.

I understand the taking of an out of focus image of a white object, but what next?

Please excuse me if this is something simple, but I have not had any experience of this.

Thank You.
KT

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Dan Kozub
Posts: 355
Joined: 24.03.2004 18:14

Unread post by Dan Kozub » 29.06.2005 22:11

no problem :)

Here is what Helicon Focus Help says about it:

"
To use this function follow these steps:

1.Prepare "white frame". After (or before) you shot all other images, make unfocused (!) shot of the white surface, so that dust on the sensor can be easily identified.
2.Start Helicon Focus, add stack of images.
3.Add dust map using "File->Add dust map" menu command.
4. Run combining process.
Please note, that dust map should have the same dimensions as all the other images in the stack."

Is this clear enough or should I describe the process in more details?

kentel
Posts: 4
Joined: 31.05.2005 13:50
Location: UK

Unread post by kentel » 29.06.2005 23:12

Hi Dan

Thanks for your time, I had read that, but thought I had missed something. It seemed too simple.

I just wonder, will this also show dead pixels?

Thanks again
KT

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Dan Kozub
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Joined: 24.03.2004 18:14

Unread post by Dan Kozub » 30.06.2005 08:13

Yes, principally it should also filter hot pixels. But for this purpose you should create grey (not white) shot, so that hot pixels could be easily identified by the program

Guest

Unread post by Guest » 30.06.2005 12:34

Thanks Dan, appreciate your knowledge.
Soon as I get my main computer rebuilt and running, I must give that Dust Mapping a run.

Using a very old computer at present, a stand-by, but has very little mem, and HD space, so used mainly for networking in emergencies.

kentel
Posts: 4
Joined: 31.05.2005 13:50
Location: UK

Unread post by kentel » 30.06.2005 12:36

Anonymous wrote:Thanks Dan, appreciate your knowledge.
Soon as I get my main computer rebuilt and running, I must give that Dust Mapping a run.

Using a very old computer at present, a stand-by, but has very little mem, and HD space, so used mainly for networking in emergencies.
Sorry Dan, this was me, I forgot to log-in.
KT

net500cg
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Joined: 26.08.2006 04:59
Location: W. Lafayette, IN
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Dust on the Sensor ...

Unread post by net500cg » 26.08.2006 06:36

Not to rain on the Helicon parade for the dust mask .. but for any sensor on a DSLR you CAN completely clean the sensor. But you must use the right tools. I had tried everything on the market to clean my troublesome Canon 350D sensor, but nothing worked satisfactorily until I used the SensorSwipe from Copper Hill Images.

I was continually having focus problems. No matter how much I tried, or adjusted, I just could not get a clean focus. I've been a professional photographer for 35 years and have been using hi-end DSLR's for 4 years (Nikon, Canon, Kodak, Fuji and Pentax) and this was the first time I just could NOT get a sharp focus.

I ruled out the lenses by using them on other cameras without repeating the problem. So, I was about the send the camera back. That's when I came across the Copper Hill site. I read it thoroughly and it made complete sense. I had noticed dust on the sensor in images shot at f16 or higher and tried to clean it off with brushes and lint-free wipes - but it was was not working. But the large dust particles were not that plentiful to cause the overall 'out-of-focus' problem. I began wondering if the surface of the sensor was bad.

As it turned out - it was the surface - but it was not BAD: just very dirty! Coated with a mixture of moisture and dust to form a 'hardened covering' that shielded the sensor from detecting the incoming light in a 'pure' context.

By using the combination of the SensorSwipe paddle, PecPad lint-free sheet and Eclipse cleaning fluid, I was able to clean the sensor to a level I was amazed at.

It took 12 cleaning application to get the entire sensor cleaned -thoroughly- but it did work. The number of times was not due to a problem with the Copper Hill system - that was just how dirty the sensor was! It took that many times get the 'scum' off the surface of the sensor.

Yes .. I was nervous as hell about 'plying the surface' of that sensor. But I was very impressed with the dexterity of the SensorSwipe. After the first 3 or 4 cleanings I was thoroughly convinced there was going to be NO DAMAGE from this process. And there was never the slightest inference of such.

So .. with the combination of the Copper Hill Images system and Helicon's Dust Mapping software - digital imaging should be realized at its top performance level.

I'm looking forward to test-driving the Dust Map as well as the Helicon Focus and Filter. I certainly hope they work as they read they do! I know a LOT of folks who will be very happy to hear about these tools!

Best regards,

les[/url]
NET500.CG
J. Leslie Booth
CiA/owner
www.net500.com
net500cg@gmail.com

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Dan Kozub
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Joined: 24.03.2004 18:14

Unread post by Dan Kozub » 14.10.2006 17:42

Les,

Thanks for your comments about dust. I have not expected that dust can be such a pain!

We are now test 4.50 beta of Helicon Filter which also has Dust Map feature.

Please contact me at dankozub@helicon.com.ua if you would like to beta test it.

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Ariel
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Unread post by Ariel » 10.12.2006 05:25

[post no longer relevant]
Last edited by Ariel on 04.05.2007 22:24, edited 1 time in total.

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Ariel
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Unread post by Ariel » 10.12.2006 07:00

[no longer relevant]
Last edited by Ariel on 04.05.2007 22:25, edited 2 times in total.

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Ariel
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Unread post by Ariel » 15.12.2006 07:20

[no longer relevant]
Last edited by Ariel on 04.05.2007 22:25, edited 2 times in total.

Guest

Unread post by Guest » 18.12.2006 06:20

Just to get some attention...

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