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G-relk

something new to me

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right, so this photo was from the lunar eclypse quite a few weeks back, but i was only going through the pics recently and noticed the ghost moon in the series of pics i took.

 

Im guessing its from my dads not-so 100% stable tripod i used, but as much as it was an undesireable effect, it is sorta neat.

 

Posted Image

 

Canon 450D

f5.6

ISO100

1/2

 

i think i was using dads sigma 75 - 300 at the time.

 

 

so, what was this ghost caused by exactly??

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Did you use a remote cable for the shutter, or a timer on the shutter? My guess is no.

 

And if it is no then what I believe happened is that the camera moved for a brief instant as you pressed the shutter button down and the brightest part of the image, the moon, created a ghost.

 

-X

Edited by Genisis X

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To me, that looks like a reflection of some sort.

 

Are you using a uv filter?. Uv filters are known to produce a ghost effect on a bright subject as the moon is about +3 stops.

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Did you use a remote cable for the shutter, or a timer on the shutter? My guess is no.

 

And if it is no then what I believe happened is that the camera moved for a brief instant as you pressed the shutter button down and the brightest part of the image, the moon, created a ghost.

 

-X

No, at that time i didnt have a remote shutter release though i do now)

 

 

To me, that looks like a reflection of some sort.

 

Are you using a uv filter?. Uv filters are known to produce a ghost effect on a bright subject as the moon is about +3 stops.

I think i did have a UV filter on that lens at the time actually.

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That sounds more likely.

 

If that is the case, it's a good example of why it's a bad idea to use a UV filter as a "protective" device.

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It is usually a good idea to use a hood as a protective device for your lens.

 

IMO, uv filters should only be used in harsh conditions due to reflections. I'll dig up an article about all this.

 

If the camera had moved, you would get a streak rather than a ghost.

 

Rob

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Consider a UV filter to be like a condom.

 

You can wear one 24/7, and consider yourself to be safer than not.

But it gets in the way and becomes a pain in the arse. Only put it on when you really need it, because what you've got does fine in the conditions where it doesn't need that particular protection.

 

Camera lenses aren't made out of fine china which risk breaking if even a speck of dust brush against them. They can take solid whacks and gritty material being flung at them with minimal damage to the front element.

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oh, wow, i didnt know a UV filter would do that.

 

I had assumed it was just movement from when i hit the shutter. the ghost came out in most of the shots i took that night, but there were about 3 or so that didnt get it at all. though having siad that, they were taken with my 55 - 250 EFS because the sigma was playing up and giving lens errors, and i dont have a filter on it.

 

That'd be sick if you could dig up that article Motiv, should be good read :)

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Pretty sure that's lens flare/reflections. Might be the filter, might be the lens itself.

 

Easy way to rule out the tripod, is to see if the "ghost" is always in the same position relative to the moon.

 

If it is always the same direction and approx distance, it's probably support related.

If it changes angle, tends to be on the opposite side of the centre point, it's not going to be support movement, but reflection related.

If the distance between the ghost and the moon changes with zoom level, it's likely to be lens related - from one of the elements sets that moves, note the degree of movement may not be proportional or in the direction you expect.

 

If the distance doesn't change much (difficult to describe since the zoom changes the range, so you need a point of reference to judge the movement, not based on pixels), then it's probably filter related (as the distance between filter and front element doesn't change as the lens zooms.

Edited by stadl

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its in a different spot in all pics. though each time its on the same side, but not the same angle or distance. all the photos it came up in were at the same focal length of 300mm, using that 75 - 300mm sigma

 

these three photos have the foreground is in the same position, but the moon has moved, and the ghosts are in slightly differant locations

 

Posted ImagePosted ImagePosted Image

 

Was it one by Thom Hogan by any chance Motiv?

http://www.bythom.com/filters.htm

that was a good read!

 

*removes cheap UV filters from his lenses*

Edited by G-relk

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Hey lord,

 

That was one of the articles I have but not the one I was referring to. Once I get on my desktop, I'll pull it out ( refers to uv filters and night shots with bright sources of light )

 

Based on your last 3 photos, I would see it is a uv filter reflection of the main front element (which is fmc hence the green hue) the differing positions refer to the convex front element and the moving subject (moon). I couldn't associate it to a internal lens reflection as you normally get more than 1 and typically happen when the light source refracts and bounces when it at the edge of field. Term normally referred to as "lens flare" but I could be wrong as stadl has mentioned a possible cause as above.

 

Rob

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