thanks for all your comments - i'll try to find good connection and post a couple of photos. The ghost imaging theory seems to make a lot of sense. i'll try and look out for those filters. i'll also try to experiment different ways to block out light reflection and post the result as soon as i can.

thanks iceblinker

I'll do as you say re: the filter. The lenses I'm using are:

- (all SMC-A) 28/2.8, 50/1.7, and 135/2.8.

They never game me flare problems (not to this extent anyway) in night photography in London. Do you think it's got to do with the environment?

...also forgotten to mention that I'm using a Pentax K20D

I've forgotten to add that I have only limited access to internet, so might not be able to post any photo by way of example.

hello,

I'm in Cairo at the moment, and the other night I was out taking photos...when I noticed a luminous spot in one of the photos (mosque courtyard, lit background - spotlights on top of columnade). I probably wouldn't have noticed it if it hadn't been in the wrong place, that is, above the colunmade, in the sky.

After trying to take a number of photos against the same and other lit backgrounds (same angle of shooting), I noticed the following:

a) whenver a spot-light or a street-light is in the picture, if the light they radiate is strong enough, the spot-light or street-light replicate itself somewhwere above its location. Usually it looks as if there were a bulb hanging from the sky. I never got more than one of these luminous spots, but they're all surrounded by halo;

b) elsewhere in the picture, the glow surrounding other (less strong) sources of light is perfectly noticeable (and looks quite annoying). I'm comparing this with night photos taken in London, where the flare is on the contrary hardly noticeable;

c) if I remove the UV protection filter, the glow at b) (or flare) becomes less noticeable. Also the lumninous spots at a) are much less visible (though still present);

d) if I use a "blue" filter, the glow at b) (or flare) disappears. The luminous spots at a) are almost gone but still slightly visible.

Cairo is extremely polluted. There's a lot of dust in the air, and probably my sensor is already covered in it. Nights are really dark here, and this seems to make any street-light look much more luminous than it would in London, for instance.

I also seem to recall reading somewhere that dust in the air can reflect light in night photography and increase the flare, but I don't know if this is really the case.

Do you know the issue, is all this happening simply because my sensor is dirty, or might there be some other reason? Any advice you could give me, also regarding home-cleaning the sensor (if that's a good idea at all), and/or trying to avoid flare? I tried using a hood, by the way, but it doesn't really make much of the difference. I also tried out different lenses, but the result in terms of flare and luminous spots is the same.

Thanks.

Thanks everyone. Now happily using JPEG on start-up. For some reason I missed out that option. Good learning experience.

Good suggestion but can't find anything of the sort. Is there something like that in the K10D?

it looks like it's working now...just that the camera - as I turn it on - it's always in RAW. If I click the RAW button, it switches to JPEG, and it remains that way till I click the RAW again.

I guess there's no way to have it ready on JPEG as I turn it on?

couldn't find reference to this (except on the K20D manual, but then it sounds a bit obscure):

- I usually shoot in RAW
- occasionally, I'd like to shoot several photos in JPEG.

Now, as for the latter, I thought that if I go to Menu>RecMode>RAW button, untick "cancel each time" + highlight JPEG>RAW + press OK twice, the camera would be ready to shoot JPEG when I turn it on, and if I want to shoot RAW, I just need to press the RAW button. Once I've shot, the camera is ready to shoot JPEG again.

Have I got it completely wrong? Whatever I do in Menu>RAW button, the camera is always on RAW anyway...pressing the RAW button does allow me to shoot JPEG, but then I'd like it to be possible to other way around as well...

Got it. Thanks everyone!