[Jack]

Hi there,

I am new to the forum and I would like to describe the problem I have. I am owner of the sony slt a33, as the title says, and the problem is that when i spot to a light source (lamp, sun) i have a bad reflection of the same object but upside down. Other than the light reflections, for example, if I spot to a lamp, i get in the photo the lamp plus the lamp upside down in a green color right down from the "real" lamb.

I must admit that I didn't know the issues when I bought it but now it seems to me that I did a bad purchase.

Can you tell me if this is a problem which can be sold with a lens hood, is it a faulty body/lense,is the ghost issue the specific models has or is the price you have to pay from the slt technology so nothing can change?

If it helps, I can upload some sample photos to see what the problem.

Thanks!

[Klaus]

[quote name='Jack' timestamp='1337715009' post='18439']

Hi there,

I am new to the forum and I would like to describe the problem I have. I am owner of the sony slt a33, as the title says, and the problem is that when i spot to a light source (lamp, sun) i have a bad reflection of the same object but upside down. Other than the light reflections, for example, if I spot to a lamp, i get in the photo the lamp plus the lamp upside down in a green color right down from the "real" lamb.

I must admit that I didn't know the issues when I bought it but now it seems to me that I did a bad purchase.

Can you tell me if this is a problem which can be sold with a lens hood, is it a faulty body/lense,is the ghost issue the specific models has or is the price you have to pay from the slt technology so nothing can change?

If it helps, I can upload some sample photos to see what the problem.

Thanks!

[/quote]



It is known that the transparent mirror can produce minor reflections in extreme situations but you seem to describe some kind of lens reflections I guess.

Anyway, maybe just upload a sample image to clarify the issue.

[popo]

A sample would definitely help, but first impressions are it sounds like a classic case of reflection off a front filter. Do you have one fitted? If so, try removing it.

[Jack]

I had a cheap cpl in fron of it, the truth is that when i removed it i did see some better results.

Anyway, i now convert the arw to jpg and upload some photos to help me guys!

[Jack]

Here you see the lamp with the reflection in the roof [url="http://imageshack.us/photo/my-images/651/dsc00389sy.jpg/"]http://imageshack.us/photo/my-images/651/dsc00389sy.jpg/[/url]

and here the lamp with the reflection (the conversion from the raw did had significant changes to the quality)

[url="http://imageshack.us/photo/my-images/401/dsc00415qg.jpg/"]http://imageshack.us/photo/my-images/401/dsc00415qg.jpg/[/url]

[url="http://imageshack.us/photo/my-images/515/dsc00376kk.jpg/"]http://imageshack.us/photo/my-images/515/dsc00376kk.jpg/[/url]

and the last one here ( here you can see the reflection front of the clock)

[url="http://imageshack.us/photo/my-images/839/dsc00380gc.jpg/"]http://imageshack.us/photo/my-images/839/dsc00380gc.jpg/[/url]



Maybe you could suggest me a way to send the raw files or to upload them in a server so you have a clearer view.

[Klaus]

These are conventional ghostings that you will experience with all cameras and lenses in such situations. ~99.9% (roughly) of the light is transmitted directly to the sensor. ~0.1% is bounced back and forth creating such ghost images.



Depending on the lens this can be more or less - it has little to do with the A33 other than that the sensor is also reflecting light back towards the lens but this applies to all cameras anyway. The semi-transparent mirror introduces a further glass element but the effect is usually negligible because of the angle of the mirror in the optical path.



As a rule of the thumbs this is least pronounced with lenses featuring few lens elements and these elements should be all multi-coated.



I used the A33 for a while myself and I really enjoyed it. It's a good camera.

[Brightcolours]

[quote name='Klaus' timestamp='1337720057' post='18447']

These are conventional ghostings that you will experience with all cameras and lenses in such situations. ~99.9% (roughly) of the light is transmitted directly to the sensor. ~0.1% is bounced back and forth creating such ghost images. Depending on the lens this can be more or less - it has little to do with the A33 (other than that the sensor is also reflecting light back towards the lens but this applies to all cameras anyway).



As a rule of the thumbs this is least pronounced with lenses featuring few lens elements and these elements should be all multi-coated.



I used the A33 for a while myself and I really enjoyed it. It's a good camera.

[/quote]

Not quite an accurate description of what happens. What actually happens is that light gets reflected back by the sensor, then goes through the lens system again. Normally it will go out the front of the lens and be gone. Now if you place a flat slab of glass in front of the lens, that outgoing light gets reflected back partly again, into the lens system. It goes through the focal point again, getting mirrored through the optical axis (that is why it ends up up side down. left side right, on the other side of the image). This then gets recorded by the sensor as party of the image.



Just about always the ghost light is caused by a filter. Only very few lenses have the ability to make a ghost light like that without a filter, this depends on the lens elements (there has to be one flat surface in front of the focal point).

Advice: do not use filters when they are not needed, ESPECIALLY in night photography where lights are very bright compared to the rest of the photo.

[Jack]

Thanks for the answer and your interest Klaus (and Brightcolours <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' /> ).

I am pretty amateur in slr's and excuse me for my ignorance, i bought this body because i found it in a really good price and checked the stats and specs with other canon and nikon models in dxomark. I then realised that a33 did covered my needs for the things i would like to do and did had a good rank in dxomark compared with other bodies.

I mainly shoot sunsets and landscapes, but when it comes to light I do have these effects. I thought that it's from the slt technology but as you say, I will have the same issues with any slr and any lens.

So, could I have better results with a lens hood or even a filter (dunno) ?

Will i have the same results with a nikon/canon body or better?

Or should i sell it and buy a nikon/canon and shoot sunset without such effects?

Do slr bodies have better results (without ghosting, flare) in these situations (light source, sunset) or are the same with slt?

Sorry for my ignorance and my many questions <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/sad.gif' class='bbc_emoticon' alt='' />

[Brightcolours]

[quote name='Jack' timestamp='1337721217' post='18450']

Thanks for the answer and your interest Klaus (and Brightcolours <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' /> ).

I am pretty amateur in slr's and excuse me for my ignorance, i bought this body because i found it in a really good price and checked the stats and specs with other canon and nikon models in dxomark. I then realised that a33 did covered my needs for the things i would like to do and did had a good rank in dxomark compared with other bodies.

I mainly shoot sunsets and landscapes, but when it comes to light I do have these effects. I thought that it's from the slt technology but as you say, I will have the same issues with any slr and any lens.

So, could I have better results with a lens hood or even a filter (dunno) ?

Will i have the same results with a nikon/canon body or better?

Or should i sell it and buy a nikon/canon and shoot sunset without such effects?

Do slr bodies have better results (without ghosting, flare) in these situations (light source, sunset) or are the same with slt?

Sorry for my ignorance and my many questions <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/sad.gif' class='bbc_emoticon' alt='' />

[/quote]

Usually, without putting a filter on the lens, you will NOT get those ghost lights.

It is right or wrong to suppose that the images you showed all had a filter mounted on the lens?



If not, then you are using a lens whose design is not typical, as most lenses on their own do not reflect ghost lights back that way.



The A33 with its translucent mirror does create a different type of ghost light, with night photography. But those do not look like what you show. The A55/A55 specific "SLT" ghost lights appear very close to the original light source, kind of like an echo of bright spots. A different phenomenon,



The ghost lights you have shown can not be avoided with lens hoods. If it is the filter causing them, just take the filter off. If it is one specific lens design causing it, use a different lens in those situations.



DSLRs are similar to your SLT with the shown ghostings. In fact, the ghost lights may show up a bit stronger with the same filter because with your SLT the mirror takes away a bit of the brightness from the reflected light, directing down and up the mirror box.

[Klaus]

I've seen all kinds of funny ghostings - without filter that is.

Just putting ghostings on the filter is a bold statement IMHO.





A cheap filter is certainly no good though.