File :-(, x, )
Just took this, about an hour ago... /p/hotographer
Nikon D70
Does anyone know how to make that purple blob not show up? It makes me sad that it was in the photo, but somehow it still kinda works for me.
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Camera-Specific Properties:Equipment MakeNIKON CORPORATIONCamera ModelNIKON D70Camera SoftwareVer.2.00Maximum Lens Aperturef/3.5Sensing MethodOne-Chip Color AreaColor Filter Array Pattern824Focal Length (35mm Equiv)27 mmSerial Number20024c79Image-Specific Properties:Image OrientationTop, Left-HandHorizontal Resolution300 dpiVertical Resolution300 dpiImage Created2008:10:31 00:10:23Exposure Time1145.5 secF-Numberf/9.0Exposure ProgramManualExposure Bias0 EVMetering ModePatternLight SourceUnknownFlashNo FlashFocal Length18.00 mmComment(c) Charles FigelColor Space InformationsRGBImage Width3008Image Height2000RenderingNormalExposure ModeManualScene Capture TypeStandardGain ControlNoneContrastNormalSharpnessNormalSubject Distance RangeUnknownISO Speed Used200Image QualityNORMALWhite BalanceAUTOImage SharpeningAUTOFocus ModeMANUALFlash SettingNORMALFlash Compensation0.0 EVISO Speed Requested200Flash Bracket Compensation0.0 EVAE Bracket Compensation0.0 EVTone CompensationAUTOLens TypeNikon D SeriesLens Range18.0 - 70.0 mm; f/3.5 - f/4.5Auto FocusCenterShooting/Bracketing ModeSingle Frame/OffColor ModeLandscape sRGBLighting TypeNATURALNoise ReductionOFFCamera Actuations7795Image OptimizationCUSTOMSaturation 2ENHANCED
>> Anonymous
that's sensor noise from the A/D amps(somebody more knowledgeable correct me if i'm wrong)
>> /p/hotographer
>>284971

Hmm. Do you how to make it not appear?
>> Anonymous
>>284973
Does it show up in every photo or something?
>> /p/hotographer
>>284975
Not sure to be honest. This is the first photo I've taken with the bulb setting because I finally got a wireless release.

I have heard of something like this happening to D70 users on deviantart, but I don't go there anymore and totally forget exactly why it happens/what they did to stop it.

If anyone has any ideas, it would help. I'm going to take some more photos later today to see if this happens again.
>> Anonymous
long exposure

the sensor gets heated up or something. same thing happened on my friends d70 during long exposures
>> /p/hotographer
>>284977
This was about 19minutes or so, I believe?

Do you know of anyway to stop this short of taking shorter exposure shots?
>> Vincent !!8LCSE0Zp1mL
Its called Amp Glow, certain camera's are worse for it than others.

Only happens with CCD sensors, longer the exposure and higher the ISO, the more they show up

Good camera's for it are obviously CMOS ones
D300, D90, D700, D3
D50 isn't bad actually

Bad ones, D200, D70 are the 2 worst (That I know of)
D200 is even worse than your D70, because it wraps around the entire picture. not just the top left!

I only know Nikon camera's myself. But its a pain to fix in photoshop.
>> Vincent !!8LCSE0Zp1mL
>>284979
nothing you can do, if you do a lot of astrophotography you may want to look into stacking images.
>> /p/hotographer
>>284981

Well damn, that is bad news. Guess I'll have to find a good range of time where that doesn't show up and try to stack the images like you said.

What a pain in the ass.
>> /p/hotographer
>>284982

Would using the in-camera long-exposure noise reduction help too maybe? I haven't tried that yet.
>> tizzou !!HuouSd+PYUs
>>284985

IIRC, using the in camera noise reduction is as long as the exposure itself. If you have time that may help but I don't know for sure.
>> /p/hotographer
>>284988
Oh wow, that is good to know. Thank you.

I'll keep it in mind for next time!
>> Anonymous
I kind of like that purple blob.
>> /p/hotographer
>>284993

I know. I don't mind it. It's just annoying that it is there and there are ways for it not to be that I just didn't know about (or remember).

Thanks. =-D
>> fence !!POey2hdozCZ
that's the aurora borealis.
>> /p/hotographer
>>284998

Not in South Carolina it's not.
>> fence !!POey2hdozCZ
>>285001

no, i assure you. it's the northern lights. they are especially strong in south carolina.

just the same, i would turn on the long exposure noise reduction, which is known as "dark frame subraction" in other circles. immediately after exposure, the camera closes the shutter and exposes for the same length of time. whatever wonky noise, amp glow and various ccd bric-a-brac that shows up is subracted from the original image. the only downside is that your 19 minute exposure turns into a 38 minute exposure. better bring along a copy of mario kart.
>> Anonymous
lol @ nikon owners. Canon >>> Nikon. My rebel XT doesn't do that because it has a CMOS, as does every other Canon DSLR.
>> Anonymous
>>285005
not helping.
>> Jeremo !iKGMr61IHM
To get rid of it 3 options:

1. turn the long exposure NR ON, it's not actually noise reduction but rather a black frame which will subtract the amp glow.

2. put the lens cap back on and do an exposure that's got the same time span, a manual black frame then subtract in photoshop

3. Shot faster shots, ie: 1 minute each, but do 19 of them then layer on top of each other at 50% opacity.

The third option is obviously the least time consuming as the other two all require double the time.
>> Anonymous
Film doesn't have this problem and there is no limit to its exposure time.
>> Anonymous
     File :-(, x)
Now all yuo gotta do is heal out those white lines and your golden

Camera-Specific Properties:Equipment MakeNIKON CORPORATIONCamera ModelNIKON D70Camera SoftwareGIMP 2.4.6Maximum Lens Aperturef/3.5Sensing MethodOne-Chip Color AreaColor Filter Array Pattern2230Focal Length (35mm Equiv)27 mmSerial Number20024c79Image-Specific Properties:Image OrientationTop, Left-HandHorizontal Resolution72 dpiVertical Resolution72 dpiImage Created2008:10:31 14:39:34Exposure Time1145.5 secF-Numberf/9.0Exposure ProgramManualExposure Bias0 EVMetering ModePatternLight SourceUnknownFlashNo FlashFocal Length18.00 mmComment(c) Charles FigelColor Space InformationsRGBImage Width0Image Height0RenderingNormalExposure ModeManualScene Capture TypeStandardGain ControlNoneContrastNormalSharpnessNormalSubject Distance RangeUnknownISO Speed Used200Image QualityNORMALWhite BalanceAUTOImage SharpeningAUTOFocus ModeMANUALFlash SettingNORMALFlash Compensation0.0 EVISO Speed Requested200Flash Bracket Compensation0.0 EVAE Bracket Compensation0.0 EVTone CompensationAUTOLens TypeNikon D SeriesLens Range18.0 - 70.0 mm; f/3.5 - f/4.5Auto FocusCenterShooting/Bracketing ModeSingle Frame/OffColor ModeLandscape sRGBLighting TypeNATURALNoise ReductionOFFCamera Actuations7795Image OptimizationCUSTOMSaturation 2ENHANCED
>> /p/hotographer
>>285070

Hey, thanks for the cropping! Saves me time of having to do it myself. =-p

Think I'm keeping the original as is, though.
>> Jeremo !iKGMr61IHM
>>285066
LOL... stfu unless you know what you're talking about next time.

Reciprocity Failure.
>> Anonymous
Okay, there's a lot of stupid anons in this thread that are confusing OP... The exposure is probably 20 minutes long (evidenced by the large change in angle of the stars). This means the blob could very easily be the aurora borealis even if you can't see it with the naked eye at the time, because it would be greatly amplified. It could also be lens flair. I suppose the other anons that point to a problem with the CCD could be right too, but the AB is much more likely.


also,>>285005, you just make canon users look like dumbfucks when you use three closing angle brackets to represent "is much less than" (it's supposed to be two).

and,>>285070
0/10
>> /p/hotographer
>>285221

Like I said before, it's the first time I tried to take a photo this way. I'm going to take more when it gets dark again and post some results.

Thanks for your input though.
>> Anonymous
resize you newfag scrub
>> Anonymous
     File :-(, x)
Nice job, OP.

Here's one I took a few weeks back.

In regards to the purple stuff, i'd guess it's light pollution.

One way to counter some of the effects of light pollution is to take multiple long exposures instead of one really long exposures and then photoshop them together.

Camera-Specific Properties:Equipment MakeCanonCamera ModelCanon EOS 400D DIGITALCamera SoftwareAdobe Photoshop CS3 WindowsPhotographerunknownMaximum Lens Aperturef/3.5Image-Specific Properties:Image OrientationTop, Left-HandHorizontal Resolution240 dpiVertical Resolution240 dpiImage Created2008:08:14 03:55:48Exposure Time489 secF-Numberf/3.5Exposure ProgramManualISO Speed Rating400Lens Aperturef/3.5Exposure Bias0 EVMetering ModePatternFlashNo Flash, CompulsoryFocal Length18.00 mmColor Space InformationUncalibratedImage Width547Image Height1200RenderingNormalExposure ModeManualWhite BalanceAutoScene Capture TypeStandard
>> Anonymous
It's a hot spot in your sensor, I have similar in my D40. To remove it, always take 2 shots when doing long exposures; one normal and one (or more) with a lens cap on and subtract the latter exposure from the first. AQlso it helps if you take so called boas shot (lens cap on and very short exposure).
>> Anonymous
is not aurora borealis idiots
>> Anonymous
looks like a light leak to me
>> Anonymous
>>285392
A lot of cameras have automatic dark frame subtraction for long exposures. The D70 might have it too.
>> Anonymous
>>285226
this is a bizzare, why do your star streaks have a brighter tip? Mine always come out even brightness throughout.
>> Project !dashI8UpO.
>>285712
rear curtain flash sync.

but really, my bet is he shot another exposure with higher ISO and less shutter then stacked it.