Weird lines with Canon 1100D

[jsmoraes]

From another topic: http://www.iceinspace.com.au/forum/showthread.php?p=1099507#post109950 7



Kevin, I read many posts in many foruns about this weird line ou similar weird line from bright stars.
None shows a tip or solution. Nor Canon has solved that problem with repairs.

The main issue is with bright stars and a vetical line. I didn't see it with my canon, up to now. It seems don't be my problem. See the photos I did to test the position of Coma corrector because of reflex, some time ago.

I saw that this horizontal black line is present in other capture of M83 that I did at July, 03.

If it has origin on cable USB ... I can not do many things. The cabel is long, and must be long. I can try the ferrite, but ... I really have doubt if it will solve the problem.
Althougt my horizontal line is different from vertical line from bright stars. It worth try !

Did you get some information about it or you think that ferrite will solve the problem ?

As there isn't any tip at the foruns to solve those weird lines... It seems to be a problem of camera model: Canon T3 - 1100D has and is problem !

http://www.cloudynights.com/ubbthreads/showflat.php/Number/5027211
http://stargazerslounge.com/topic/207337-vertical-lines-below-stars/
http://stargazerslounge.com/topic/176302-dark-lines-emanating-from-bright-stars-eg-in-m45/
http://www.dpreview.com/forums/thread/3535349
http://www.webastro.net/forum/showthread.php?t=92951

As this line only appears when I strech too much the photo ... perhaps it will not be a big problem.

My old age says: if you can not win ... surrenders ! :sadeyes:

First photo: Canopus - single frame - ISO 6400 - 16 seconds - RAW converted to JPG

Second photo: Canopus - single frame - ISO 6400 - 16 seconds - DSS - streched in Photoshop.

note: all problem has a solution. When a problem hasn't solution... it is not a problem. It is a real fact: immutable reality. :shrug:

So, I haven't problem with my Canon. I just have a Canon... 1100D ... with an weird line attached !

[cometcatcher]

Hi Jorge, your line is different to the ones in the links above. It doesn't come from bright stars in your pics. I'd try the ferrite beads or a different cable. A loose wire in the cable might do it also, so yeah try a different cable first.

[jsmoraes]

An observation that I didn't yesterday: the photos with Canopus haven't the black line.

They were done with battery, and the M83s were done with AC power. A not made in by Canon accessory.

It is another possibility. The DC can have much ripple by poor filtering. An addicional eletrolitic or tantalum capacitor maybe necessary. :question:

I will test this possibility.

[cometcatcher]

Starting to sound like you've found the culprit.

[Forgey]

I had the lines problem with my 1100D and couldn't work out whey they all of sudden started to appear, so I gave up imaging with it.

[jsmoraes]

What kind of line, Paula ? The black from a bright star or horizontal like mine as shown in http://www.iceinspace.com.au/forum/attachment_browse.php?a=165940 ?

[Forgey]

Mine were the vertical lines like the ones here:
http://stargazerslounge.com/topic/207337-vertical-lines-below-stars/
http://stargazerslounge.com/topic/176302-dark-lines-emanating-from-bright-stars-eg-in-m45/

[raymo]

I guess the next question is does Paula use A/C or battery power?
I have now taken around 1500 subs with my 1100D on battery power, and have seen no trace of black lines.
raymo

[Forgey]

I was using batteries. Never had A/C for it.
I have added a picture of what my lines were looking like.

[raymo]

Hi Paula, the lines in your pic appear to be a completely different phenomenon from the others we have seen. Firstly, they don't have any connection with specific stars; there are far more of them, and the pic contains a lot of noise. I suspect that the lines are part of the noise. Let's see what people more knowledgeable than me think.
raymo

[Forgey]

The image is a little out of focus, it was stacked in DSS with darks and flats. I'm was/am stumped with what it could be. At the time I was thinking it had something to do with removing the IR filter but it was working fine then all of sudden my images started coming out like this.
I have since moved to CCD imaging and I no longer have the 1100D.

[jsmoraes]

I agree with raymo. Yours lines are different. As you haven't more the 1100D, discuss about them has no sense.

But they seems more as noise, or bad influence of darks and flats. Mainly flats. Flast change the area black or gray, by dusts or others anomalies, with white. Flats only hide dusts if they are small and few. And as I said... hide.

And, it is real ! The photo hasn't weird lines... the photo, it self, is weird. To change to CCD was a good idea.

[cometcatcher]

As well as another capacitor or two Jorge, it wouldn't hurt to add some ferrite beads to your power cable also. Or grab a couple of spare batteries.

That's one thing I really like about my K-5, it can run all night on one charge.

[jsmoraes]

I did the test with battery... and ... the line exist ! The Ac-Power is not culprit.

Therefore... let's try the ferrite !

[jsmoraes]

I did test with and without filters, and with original USB cable from Canon.

The line persists ! :mad2:

Up to now, out of suspicion:


use of filters
time of expositon and ISO
ac/dc converter
size of USB cable

[JB80]

I get the same noise in my 450D pics as what is in Paula's pics, which I agree is different from the other pics in this thread. It just started happening out of the blue.
I call it streak noise, it's horrible.

The best explanation I have read but in truth haven't tested it is it comes from temperature spikes or drops between subs/flats/darks etc.
Adding bias seemed to help but then maybe that night was just more stable.

I'm hoping it is more a case of variable outside temps rather than the Camera getting old and overheating or it could be a battery getting hot.

Then again I have read that one solution is to stop using darks which is a simple way of going about it.
Also to dither but how to go about that when using the Polarie and whilst I'm snoozing in font of the telly escapes me.

Sorry to veer slightly off topic Jorge.

[cometcatcher]

1. Kick the tripod leg between exposures and 2. Don't sleep in front of the telly. ;)

[jsmoraes]

I didn't test with ferrite because I didn't get one yet.

Now I did a test with shot of a wall with the normal lens, Canon USB cable and Canon EOS utility.
I didn't get the exact conditions of astrophotography, but it seems that the line has origin with the firmware of Canon camera.

The photos attached were with intense adjust of HDR, bright and contrast. They were few photos. And two are with stack in DSS

I see many horizontal lines, that with low luminosity, many photos and hard process... Any one can be transformed in horizontal black line.

first photo is mosaic of two photos with different ISO and time of exposition.
second photo is five photos stacked in DSS with dark and bias
third photo is five photos stacked in DSS only with bias


I will try find the ferrite, but ... I don't know ... it smells ... Canon !

[jsmoraes]

:sadeyes: I forgot to do a simple and important test to find who are culprit to create the black horizontal line:



capture image only with adapter Canon-T2 and extensor T2 - without nothing more

With it I can know if it is problem with the camera.

Attached is the pattern of the line. The photo was only converted from 32 bits DSS to 16 bits with HDR curve in Photoshop.
Channel Red, Green and Blue.

The last photo is zoom to see the pixeis of the line

[jsmoraes]

I was analysing that line, and I saw that since 14/06/2014 I have it in CR2 file. I don't have CR2 from previous date.

It seems that the problem is increasing the intensity. And I only perceived it by now.

The only thing I did that can cause damange to the camera was to generate long darks to use with long exposure of H alfa. Maybe it increased the problem in the sensor.

The main problem is with red channel. Little with green. And nothing with blue. Therefore it seems that it is not from any kind of obstruction, nor dust, nor damage on the glass and infrared filter or so.

It seems to be loose of intensity of information on an horizontal area of the sensor.

I don't remember what set I was using that time (June, 2014). Now, I am using -3 of sharp, -3 of contrast , +1 saturation and zero to color tone. I was changing sharp and contrast. I will try another set to see if the presence of the line becomes more faint.

[cometcatcher]

That's weird that it appears strongest on the red channel.

[jsmoraes]

I found the message with reference to black line in the image. It was from Octane (Humayun) in the topic http://www.iceinspace.com.au/forum/showthread.php?t=123022&highlight=black+line&page=2

The problem is different. He had a crack in the sensor. Under that black line there aren't any information.

Mine, I have some information, but with low level with reference to others lines. And mainly with red pixels.

As I have some faint presence in the green channel, maybe it is a problem of assembly of pixels at that area.

I don't know, but if the the sensor is mounted with matrix strips of pixels, perhaps the matrix at that position has any problem of response. Or it can be with the bayer film over the matrix of pixels.

Well, what I can do is to find an way to reduce its presence.