Why does this ghost happen? - DPChallenge Forums

04/03/2005 08:59:10 PM · #1

Is this ghost in my picture normal?
its a 1/15 sec exposure, at f5.6 and im wondering if there is something wrong or is this ghost image normal?
I have a Digital Rebel 300D.
Thanx for any help.

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Message edited by author 2005-04-03 21:01:19.

Tamron SP AF 28-75mm f/2.8 XR Di for Pentax

04/03/2005 09:02:53 PM · #2

It's an internal reflection within the optical system. Are you usig a filter on the lens? If so try removing it and reshooting, see if that helps. It also could be a reflection off the rear element of the lens, and in that case it's just a function of that particular lens, in combination with the fact that the sensors in digital cameras are more reflective than film, and don't scatter light much, but reflect a true image.

Artyste

Sony Ericsson W810i

04/03/2005 09:03:06 PM · #3

It's a matter of optics. The light shining from that square on the bottom is so bright that it's reflecting through the lens and ending up on the sensor. It's the same sort of deal that you get when you get lens flare from the sunlight or other brightly lit object. You'll either want to find some way to diffuse the light coming off the square, or find another angle to shoot from.

04/03/2005 09:07:25 PM · #4

I had this happen when i was shooting downtown Chicago and the halo around the top of the John Hancock building did that ghost image and ruined my night time photo.

04/03/2005 09:10:26 PM · #5

Originally posted by ChasSourek:

I had this happen when i was shooting downtown Chicago and the halo around the top of the John Hancock building did that ghost image and ruined my night time photo.

Was that with the same lens you used in this shot? What lens or lenses have you had this happen with?

04/03/2005 09:22:34 PM · #6

The only lens that i have so far is the one that came with the camera.
A 18-55

04/03/2005 10:01:50 PM · #7

Originally posted by ChasSourek:

The only lens that I have so far is the one that came with the camera.
A 18-55

And are you using a filter (like a UV filter) on the lens?

Message edited by author 2005-04-03 22:02:41.

04/03/2005 11:56:05 PM · #8

Yes i am using a UV filter.
A Tiffen 58mm HAZE-1

04/03/2005 11:58:47 PM · #9

Try an experiment... set up a shot (use a tripod so you can get the exact same shot more than once) that you know will give you ghosting, shoot, then remove the filter, and shoot the same shot again. Does the ghosting become less severe? How much?

04/04/2005 12:04:18 AM · #10

I will try that.
Is this a normal thing to happen when a filter is in place?
Maybe the wrong kind of filter?
Or might there be a problem?
I was shooting at the full moon the other night and had this happen.
Frustrating because the pics were good except for that ghost.

04/04/2005 12:08:32 AM · #11

filters can contribute to it, especially if they are not coated. The more light that can reflect off of the back side, the more likely that a ghost image will be visible.
It also depends on the lens. Some are more prone to this than others. I don't know much about the 18-55, no direct experience.

04/04/2005 12:10:41 AM · #12

Ill try the expariment with and without the filter.
Thank you for your help.
Im hoping to solve this problem cause it has screwed up a few pictures for me so far.

gwphoto

Canon EOS-1D Mark II

04/04/2005 12:16:21 AM · #13

Try putting your camera on a tripod and then look at the front element of the lens and see if you see the reflection in the glass. If you do, take your hand or a card and shade the lens till the reflection foes away. A lot of pros use a large compendium shade to stop just that. You will also get better photos with a good lens shade.

04/04/2005 12:18:41 AM · #14

Originally posted by gwphoto:

What he's seeing will not be stopped by a lens shade. It's not off-axis light, it's light from within the lens field of view.

04/04/2005 12:20:11 AM · #15

Correct, there is NO light coming from the sides.
The only light source is the suns reflection off of the wall

gwphoto

Canon EOS-1D Mark II

04/04/2005 12:23:43 AM · #16

Originally posted by kirbic:

Originally posted by gwphoto:
Try putting your camera on a tripod and then look at the front element of the lens and see if you see the reflection in the glass. If you do, take your hand or a card and shade the lens till the reflection foes away. A lot of pros use a large compendium shade to stop just that. You will also get better photos with a good lens shade.

What he's seeing will not be stopped by a lens shade. It's not off-axis light, it's light from within the lens field of view.

It sure looks like a reflection in the optics from a brihgt source that can be shielded with a card or a hand. I have shot in areas with extreme light and reflections. I have learned to look at the fron of the lens and check if a light source is hitting it.

04/04/2005 12:24:52 AM · #17

If you look at the reflection, it is an image of the bright square that is also in the frame. You cannot shield an object that is also in the frame, without blocking part of the frame.

gwphoto

Canon EOS-1D Mark II

04/04/2005 12:26:03 AM · #18

Originally posted by kirbic:

If you look at the reflection, it is an image of the bright square that is also in the frame. You cannot shield an object that is also in the frame, without blocking part of the frame.

You sure can...