Reflections

[Camellia]

I've just bought some black perspex to replace my black cardboard for backgrounds. The perspex has matte on one side and gloss on the other.

I'm finding it a bit of a challenge to get a good reflection off the gloss. I can see a reflection when I look at my set up, but the camera is not capturing it very well. It seems to me that there is some sort of trick to the exposure. If I set the exposure for the object, the reflection is lost or diminished. I've tried adjusting the exposure on the reflection in PP but I wondered if anyone has any tips?

Thanks

R

[rob marshall]

Raylee

You need the right kind of material. I use a black acrylic perspex sheeting that is coated gloss on both sides. I get mine from Ebay from a company called Trent Plastics based in Gainsborough, UK. I use 500mmx500mm. Here is the link...

http://cgi.ebay.co.uk/3mm-BLACK-ACRY...item5d2a6bbb61

And here is their Ebay shop link...
http://stores.ebay.co.uk/Trent-Plastics

I had a look on Ebay Australia, but couldn't see an equivalent product. If you can't get your material to work you could try emailing Trent, and ask how much shipping is to Australia - quite a lot I should think.


And here is what mine produces. This one was adjusted in CS5 to get the reflection side boosted so they match evenly. I'm just showing this one to show it can be done.


And this one has no adjustment, so you can see how well the reflection comes out.


Two other things are important.

1. Lighting can make a big difference. A reflection is not just dependent upon a glossy surface; it needs a good light to reflect the subject. For the perfume bottle I had a soft diffused studio light, slightly above the level of the subject and at 45 degrees to the subject from the front.

2. Camera angle is also critical. Try this experiment. Place your sheet on a table with a piece of black art board behind the subject, which should be placed on the perspex. Stand near the table and look at the reflection. It won't look very impressive. Now slowly crouch down so your eyes gradually get down to table level, and you should see an improving reflection. You need to get the camera as low as possible - but there's obviously a limit when you start to get the edge of the perspex in the shot.

I don't use any special exposure compensation, because I always use studio flash with a hand-held light meter. If you are not using a meter, then switch to spot metering. This will ensure the subject is not over-exposed (the camera can get confused with all that black). It will also have the effect of making the black very black, excluding any stray light around the edges.

You need to be very careful to clean the plastic, so it is free of dust. Otherwise you will become a very close friend of the cloning tool in Photoshop.

[jeeperman]

I have no perspex but instead have used glass painted black on one side. An old round 4ft coffee table infact. It is what I used to shoot the bike shot I recently posted and the picture below. So far I have worked out my shooting angles but the lighting gives me fits. I feel the lighting and reflections of everything in the room will be the roughest to work out. The bike shot required a lot of work as the table reflected the wall, door and everything else. For that I had to hang a back drop behind me...hence the blueish tone. I had no black sheets. lol While horizontal I need only give myself a small black backdrop to combat reflections the other side of my smaller subject. Basically once you get the reflection, everything else is trial and error. For me....a lot of error.

[rob marshall]

Paul

The problem with glass painted on one side is that it's basically a standard mirror, and that can cause ghosting of the reflection when the camera angle is close to the flat reflective surface. It was OK in your bike shot, because the bike was in front of the perspex, and so was nearly a direct reflection. As soon as you start to get more of a camera angle you will get problems with it. What you really want is a material (like the black perspex) which reflects on the surface, not at the rear, like a mirror or your method.

[jeeperman]

Hmm that is something I will have to look out for Rob. I had not noticed this as of yet. I wonder if the glass is also smoked if it would make a difference. I believe the table is. The struggle I did notice in the bike shot was a bit of distortion depending upon angle of the glass. Thank you for clueing me in. as I hope to at some point emulate the quality of your shots. They are quite superb.

[Camellia]

Raylee

You need the right kind of material. I use a black acrylic perspex sheeting that is coated gloss on both sides.

I'm pretty sure that's what I've got - cast acrylic sheet. The gloss scratches very easily.

1. Lighting can make a big difference. A reflection is not just dependent upon a glossy surface; it needs a good light to reflect the subject. For the perfume bottle I had a soft diffused studio light, slightly above the level of the subject and at 45 degrees to the subject from the front.

At the moment I'm basically using natural light at one side, sometimes I'm using a desk lamp. I think lighting may be my problem.

2. Camera angle is also critical. Try this experiment. Place your sheet on a table with a piece of black art board behind the subject, which should be placed on the perspex. Stand near the table and look at the reflection. It won't look very impressive. Now slowly crouch down so your eyes gradually get down to table level, and you should see an improving reflection. You need to get the camera as low as possible - but there's obviously a limit when you start to get the edge of the perspex in the shot.

I've noticed that. And the wrong angle brings in other reflections.

I don't use any special exposure compensation, because I always use studio flash with a hand-held light meter. If you are not using a meter, then switch to spot metering. This will ensure the subject is not over-exposed (the camera can get confused with all that black). It will also have the effect of making the black very black, excluding any stray light around the edges.

I was using spot metering today when I was experimenting. I was metering off a strawberry but that resulted in the reflection not being very strong. The strawberry was spot on but the reflection was lost in the black. I think lighting is the answer - I don't think my light is strong enough.

You need to be very careful to clean the plastic, so it is free of dust. Otherwise you will become a very close friend of the cloning tool in Photoshop.

Don't I know it!

I think I'll be practicing quite a bit but thanks to you Rob, I know what can be achieved under the right conditions.

Thanks!

R

[Camellia]

I took this photo a couple of days ago in the early evening with a desk lamp to supplement the natural light.

[rob marshall]

Raylee

I'm busy until this evening (morning now) but I'll try one later with a desk lamp.

[Camellia]

Raylee

I'm busy until this evening (morning now) but I'll try one later with a desk lamp.

Thanks Rob!

R

[rob marshall]

Raylee

OK, I just shot this one on my perspex. For one test shot I used a halogen desk lamp (not diffused), and for the second I used my studio flash head which was diffused.

Here's the RAW (no processing) straight from the camera for the halogen.


And here's the RAW for the studio flash version


The halogen is darker in the areas that are meant to be black because the halogen light source was quite small and concentrated. So most of the light fell onto the box/watch. However, it has resulted in a slightly harsher look. The studio flash version has a softer look. There is more light spill, but you can improve that in RAW edit and Photoshop.

I processed them both in CS5 to see how they compared. here is the halogen version.


and here is the Studio flash version


There's not a huge difference between them, and the reflection is pretty good in both. The studio flash will always give a softer look (if that's what you want) with less harsh shadows. Although, you could diffuse the halogen with a cloth of some kind - I see Jiro did that with one of his shots the other day. It's just easier with the studio flash, and metering is a lot quicker and more reliable. You can get a good reflection though with an ordinary lamp.

[Camellia]

Thanks Rob. I'll keep experimenting and posts some shots later today.

R

[maloufn]

Raylee,

I am just reading a book called "Light - Science and Majic" a must for understanding the physics of light in photography. It is an eye opener. But I am sure it has something to do with the position of your camera in relation to the "family of angles" ie the light path/rays from source to object and how it is reflected off the surface. I am sure some of the light gurus will enlighten you. Otherwise you might have to wait until I finish my book!!!

Regards

Nasseem

[rob marshall]

Raylee,

I am just reading a book called "Light - Science or Majic" a must for understanding the physics of light in
photography. It is an eye opener.

It's a brilliant book - really useful. I'm re-reading mine at the moment. http://www.amazon.co.uk/Light-Scienc...6622400&sr=1-1

[maloufn]

It's a brilliant book - really useful. I'm re-reading mine at the moment. http://www.amazon.co.uk/Light-Scienc...6622400&sr=1-1

Yes I think anyone serious about their photography has to have a good understanding about light and how to manipulate it, how it is reflected, diffracted, absorbed etc by objects and how it is captured by the camera placed in different positions. I am just about to start a Lighting course with the Australian Centre for Photography over 10 weeks. I am sure the book will be a great help.

Nasseem

[Camellia]

Yes I think anyone serious about their photography has to have a good understanding about light and how
to manipulate it, how it is reflected, diffracted, absorbed etc by objects and how it is captured by the
camera placed in different positions. I am just about to start a Lighting course with the Australian Centre for Photography over 10 weeks. I am sure the book will be a great help.

Nasseem

Lucky you Nasseem - I subscribe to the ACP newsletter and their courses look really good.

I'll check out the book - thanks.

R

[Katy Noelle]

Raylee,

I am just reading a book called "Light - Science or Majic" a must for understanding the physics of light in
photography. It is an eye opener.

Regards

Nasseem

That's really funny! I just ordered it (FINALLY) after having it in my "cart" for over three months!

[maloufn]

That's really funny! I just ordered it (FINALLY) after having it in my "cart" for over three months!

Katy,

Coincidental!! It certainly gets you thinking and also explains why and how light is working. Youll have a
different understanding of how and why your pictures look the way they do.

May be we (Raylee, Rob, you) can discuss unclear points in the book further when we have all read it.

Good shooting Katy. You got some beautiful simple shots.

Nasseem

[Katy Noelle]

Oh, thanks, Nasseem!

[MiniChris]

It took me a while to find one, but I got one of the old Anti-static brushes used for "dusting" off large format negatives and after a good cleaning with a damp chamois, I wait until the moisture dries from the surface, then lightly pull the anti-static brush across the top of the plexiglass. Using this method, I've only had to clone out a few offenders and they were quite small.