White Background Exercise

[Stagecoach]

One of the areas I have struggled with over the years with my macro work is trying to achieve a white background and generally go for black because I have found it way easier. I have used flash predominately for inside work and past attempts have used flash for the subject and then another one or two to light a white backboard but the results have been pretty hit and miss resulting in underexposed and uneven backgrounds.

It is now my intention to do more work inside during daylight with natural light as I have no direct sunlight coming into the room where my subjects will be but have excellent diffused light, so today I experimented to see if I could confidently achieve a white background.

I used a piece of opaque white plastic around 200mm behind my subject and behind this had my flash fitted with a diffuser around 150mm from the plastic.

The camera was set in manual with required aperture and speed adjusted to achieve the natural light exposure I wanted and a couple of shots taken to confirm all was correct and note taken of the histogram. The flash was then adjusted to approx 1/4 power and a further shot taken triggering the flash from the camera. The histogram showed a clear narrow peak towards the right and flash power was increased until this narrow peak was almost at the far right without clipping.

Hey presto, minimal PP work and here's the result



During the exercise I played around with moving the opaque plastic at different distances from the subject to vary affects. The subject was chosen for its shape and hair detail of the stalk to ensure I retained this detail, and also to show that I do not just grow strawberries

On my monitor I can see a very small area bottom right that is not quite white probably caused by the flash not being aimed quite right.

Grahame

[Mike Buckley]

People who haven't made a photo this way can't appreciate how difficult it is to get an even white background without using post-processing. I would have "cheated" in the bottom right corner by post-processing that area to make it white.

I use mostly 5500K compact fluorescent bulbs in my makeshift studio, so I marvel at how you can get the lighting that you want using flash. I realize they have modeling lights but I study and fine tune the lighting for so long that I would go crazy using flash.

Despite my admiration about that, the remarkable aspect of this photo for me is the absolutely perfect depth of field. If it had been just the slightest bit smaller or larger, it would have been a very different photo in my mind. This photo has to be viewed at its largest size to fully appreciate that.

[Dusty]

Spot on with this image, lovely lighting which emphasises the subject.
Dave.

[Stagecoach]

Mike, thanks for the encouragement. The lighting on the tomato is natural window light and there would be some coming off the illuminated panel at the back but I kept that to a minimum on this shot.

I was sat behind the camera so that would have shielded some of the light directly from the front. It required a minor correction of white balance as would be expected.

I'll do a couple more this weekend and make sure I record the shots without and with the plastic rear panel lit with the flash. One of the beauty's of the set up was that I could simply sit behind the camera using it in commander mode to vary the flash power and trust what I was seeing on the histogram as you can not judge white by looking at the LCD.

Grahame

[Stagecoach]

Thanks Dave, I grow these tomatoes for their uneven shape

[Kaye Leggett]

Grahame - its a beautiful photo and thank you for sharing in such detail how you achieved it. I like messing about at the macro level and I shall be trying your technique sometime soon.

[Brownbear]

Stunning image. Thank you for sharing your technique. I would like to try this one day, too... so very helpful

[Stagecoach]

Thank you Kaye, I love your wording 'messing about' because to me that's what it's all about.

[Stagecoach]

Hi Christina,

What a compliment! Now to see if I can get repeatable results using other subjects.

[Donald]

That's a sublime image.

What hasn't been explicitly mentioned, although indirectly referred to in the praise given, is the strength of the composition ( or call it the positioning of the subject, if you like). It just works. I think it's perfectly balanced.

[Brownbear]

Hi Grahame,

Not a compliment, just a fact.. I don't have any doubts at all that you will.

Hi Christina,

What a compliment! Now to see if I can get repeatable results using other subjects.

[ajsmith]

I like this photo. The composition, color and depth of field. Nice!

[Stagecoach]

Hi Donald,

I had to look up the word sublime, thank you.

The original had a lot more white space around it because I wanted to check for variations in brightness and the exercise had concentrated more on achieving that rather than producing a picture. Cropping and positioning is something I now put more effort into using the knowledge that I have learnt here.

[Stagecoach]

Hi Ali,

It's surprising that the humble tomato is not only appreciated due to its taste but also it's modelling skills, thank you.

[Colin Southern]

Hi Ali,

It's surprising that the humble tomato is not only appreciated due to its taste but also it's modelling skills, thank you.

But is it a vegetable or a fruit?

[Colin Southern]

One of the areas I have struggled with over the years with my macro work is trying to achieve a white background and generally go for black because I have found it way easier. I have used flash predominately for inside work and past attempts have used flash for the subject and then another one or two to light a white backboard but the results have been pretty hit and miss resulting in underexposed and uneven backgrounds.

During the exercise I played around with moving the opaque plastic at different distances from the subject to vary affects. The subject was chosen for its shape and hair detail of the stalk to ensure I retained this detail, and also to show that I do not just grow strawberries

On my monitor I can see a very small area bottom right that is not quite white probably caused by the flash not being aimed quite right.

Grahame

Hi Grahame,

Yes - it is trickier than most people realise.

In essence, what you're aiming for isn't so much a "white background" as it is the correct RATIO of light between subject and background - and that ratio is typically 1:1, with just a touch more on the background.

Some folks advocate "nuking" the background by a couple of extra stops; that works well when one is using a sheet and wishes to kill the wrinkles, but there's a price to pay in doing that, and that price is loss of fine detail (it looks like this may have occurred a little in this shot).

The best way to achieve what you're after is to use a light meter and a colour card; spot-meter the white patch on the card and then the same for the background - then adjust the background to be about 1/3 stop brighter. That way if the foreground is correctly exposed (white's are whites - middle grays are middle gray - and blacks are "black") then when you normalise the levels in post-production, the background will always be a smidgen higher, but not so high as to call significant loss of fine detail that's in the line of fire.

With regards to the even-ness of it - if you want to even it out in-camera as such then "go for it", but in truth, it's a big time-waster; so long as the transition zone around where the subject finishes and the background starts is correct then - so long as you ensure that area is "255" in post-production then it's usually a brutally quick process to max out the rest of it (usually a digital GND set a couple of stops higher or even a paintbrush will fix it in a few seconds). Just be sure to check it though; I've been guilty of missing the checking stage on several occasions - publishing the work - and then discovering all kinds of brush marks visible on other peoples monitors that are adjusted slightly differently to mine.

Also - don't be afraid to experiment with rim lighting in conjunction with a white background -- it can add a nice softness to the edges of the image (if suitable for the subject).

Hope this helps

[Stagecoach]

Achieving the result you want is good but it's even more useful when you remember how you did it and if you can repeat it confidently so today I had another go. So two more subjects and same process with the intention of achieving a pure white evenly exposed background with the subject lit by natural window light.

f13, 1/2s, ISO200


f22, 1.3s, ISO200


Further lessons learnt;

a) use the camera blinkies to show the position of clipping within the frame and align the flash to correct this. Basically its centre should be inline with the camera and subject both vertically and horizontally. I have not experimented with flash light angle or the difference with using it with or without the diffuser.

b) There is a slight difference between the blinkies on the camera and that seen with the image open in ACR. This is due to the camera histogram and blinkies being determined by the in camera jpeg settings.

The results were as hoped with very minor error as that in the first post very easily corrected using levels.

Grahame

[Stagecoach]

Hi Colin,

Your advice is well received. I could not remember if the background was supposed to be over or under the subject so was going to check tonight. So from what you say there was no need for me to pull the slight overexposures back in ACR with the recovery tool.

I do not have a light meter although still retain a flash meter I purchased about 40 years ago which I suppose is now considered from the Ark as my camera has been

Lighting of the subjects was not really bothered about but something I will address when producing images for the subject rather than the background.

Cheers

Grahame

[Colin Southern]

Hi Colin,

Your advice is well received. I could not remember if the background was supposed to be over or under the subject so was going to check tonight. So from what you say there was no need for me to pull the slight overexposures back in ACR with the recovery tool.

Normally a camera will expose a middle gray about 4 stops down from sensor saturation - and a white highlight is 2 stops above middle gray - so - with a RAW exposure your highlights are typically a little over 2 stops below sensor saturation which means they present as being quite gray before being adjusted in post-processing -- which inturn means you always have to adjust them.

Normally when you adjust a highlight you want to push the brightest part (in post processing) up to the point where it clips - and you'll usually want that portion that you adjust to be part of your subject (assuming that it has white in it). If your background highlight is lower than your subject highlight then when the subject highlight is correct then the background will be a shade of gray, which isn't a good thing (unless you want that).

If the background is a smidgen higher then when the subject clipping point is set correctly then the background will be nicely clipped.

I do not have a light meter although still retain a flash meter I purchased about 40 years ago which I suppose is now considered from the Ark as my camera has been

When you start working multiple light zones they save a LOT of time in getting both exposures and contrast ratios correct.

[Mike Buckley]

it's even more useful when you remember how you did it

I record that information in the photo's metadata.