Photographing flowers in sunlight and posterised colours

[Steve F]

15 minutes ago, MDM said:

 

That is an excellent demonstration why it is a very bad idea to shoot JPEGs: white balance is locked in (and the relationship between the colours. Also highlight detail, sharpness and noise reduction settings are locked in. 

 

Looking at your LR settings for the raw, I would suggest you take the highlight slider well down as that should recover some highlight detail (although the histo is showing max white at about 90% which is low so you are definitely losing highlight detail ). My guess is the problem is with the lighting. Full frontal sunlight is not ideal for showing texture and detail. 

Thanks MDM, I've given up on this raw file, I just can't get the colours looking realistic. Agree that it's the lighting - too harsh.

[Bill Brooks]

Yellow is a combination of the red and green channel with red higher than green. Images with yellow should be underexposed to hold detail in the red channel. 

 

Take a test shot at normal exposure. Consult the camera 3 colour histogram and note the red channel climbing up the right hand side, indicating that the red channel is overexposed and has lost detail and shifted the yellow colour towards green. Cut back exposure until the red channel meets the end of the histogram but does not climb up the side. So now, on the final exposure, you probably have red 254 Green 235 and blue 20 in the yellow areas of the image only.

 

This means that the red channel is as exposed as much as it can be and the green is bright and the blue is dark in the yellow areas of the image. All colours have the same ratio to each other so colour is correct without detail loss. However elsewhere in the image all colours are correct but underexposed.

 

Raise all the shadows in software so that the Red and Green are not changed in the yellow, as Red and Green are considered highlights. However all shadow underexposed RGB are brightened elsewhere in the image. The final image is correctly exposed overall and retains the correct yellow without loss of detail.

 

Full harsh sunlight. Note the open shadows on the blue and correct yellow.

 

 

[Steve F]

6 minutes ago, Bill Brooks said:

Yellow is a combination of the red and green channel with red higher than green. Images with yellow should be underexposed to hold detail in the red channel. 

 

Take a test shot at normal exposure. Consult the camera 3 colour histogram and note the red channel climbing up the right hand side, indicating that the red channel is overexposed and has lost detail and shifted the yellow colour towards green. Cut back exposure until the red channel meets the end of the histogram but does not climb up the side. So now, on the final exposure, you probably have red 254 Green 235 and blue 20 in the yellow areas of the image only.

 

This means that the red channel is as exposed as much as it can be and the green is bright and the blue is dark in the yellow areas of the image. All colours have the same ratio to each other so colour is correct without detail loss. However elsewhere in the image all colours are correct but underexposed.

 

Raise all the shadows in software so that the Red and Green are not changed in the yellow, as Red and Green are considered highlights. However all shadow underexposed RGB are brightened elsewhere in the image. The final image is correctly exposed overall and retains the correct yellow without loss of detail.

 

Full harsh sunlight. Note the open shadows on the blue and correct yellow.

 

 

 

 

Bill, firstly, great image. Secondly, I love technical aspects and learning new things! So I really needed to underexpose this shot... I can see even on my underexposed raw file that the red is climbing up on the right hand side so is overexposed on the highlights.

 

I tried photographing again tonight before dusk, but didn't have enough light to handhold and get enough detail. Will photograph tomorrow using something to diffuse the light and try to follow the advice you've given above. Fun and games...!

[Steve F]

1 hour ago, John Mitchell said:

Doesn't converting from RGB to sRGB sometimes cause some loss of detail and definition? That might be adding to the problem.

 

 

Could be. I'm working in Adobe RGB and don't softproof in sRGB...

Edited September 13, 2020 by Steve F

[Cal]

44 minutes ago, Bill Brooks said:

Yellow is a combination of the red and green channel with red higher than green. Images with yellow should be underexposed to hold detail in the red channel. 

 

Take a test shot at normal exposure. Consult the camera 3 colour histogram and note the red channel climbing up the right hand side, indicating that the red channel is overexposed and has lost detail and shifted the yellow colour towards green. Cut back exposure until the red channel meets the end of the histogram but does not climb up the side. So now, on the final exposure, you probably have red 254 Green 235 and blue 20 in the yellow areas of the image only.

 

This means that the red channel is as exposed as much as it can be and the green is bright and the blue is dark in the yellow areas of the image. All colours have the same ratio to each other so colour is correct without detail loss. However elsewhere in the image all colours are correct but underexposed.

 

Raise all the shadows in software so that the Red and Green are not changed in the yellow, as Red and Green are considered highlights. However all shadow underexposed RGB are brightened elsewhere in the image. The final image is correctly exposed overall and retains the correct yellow without loss of detail.

 

Full harsh sunlight. Note the open shadows on the blue and correct yellow.

 

 

 

This is a great post, I didn't understand the significance of the colour histogram until now. Will change how I shoot going forward particularly with shots where I'm having odd colour balance issues. Every day is a school day... even had to get my camera out to remind me that yes it does show a colour histo!

Edited September 13, 2020 by Cal

[MDM]

13 minutes ago, Steve F said:

 

Bill, firstly, great image. Secondly, I love technical aspects and learning new things! So I really needed to underexpose this shot... I can see even on my underexposed raw file that the red is climbing up on the right hand side so is overexposed on the highlights.

 

 

 

The red is not overexposed on the highlights in your image Steve. If it was it would be clipping (i.e. hitting 100% - use the clippings indicators) whereas it is only barely on about 90% and that is after you have increased the overall exposure and the whites. Different cameras have different ability to capture highlight detail and your Sony should be excellent in that regard. Underexposing significantly is not good as it will negatively affect the colour and tonal range. It s better to go as far to the right as you can without clipping the highlights and pulling back the detail in LR. The camera histogram is based on the JPEG so spending time on trying to get it right in camera is of dubious value. Just try a series of exposures a stop apart and be aware that if you expose off the flower itself then you will underexpose anyway. For flower photography where colour is critical, a good gray card such as the one by X-Rite is very useful for correctly exposing and later colour balancing in LR. 

[MDM]

Deleted

Edited September 13, 2020 by MDM

[Steve F]

14 minutes ago, MDM said:

 

The red is not overexposed on the highlights in your image Steve. If it was it would be clipping (i.e. hitting 100% - use the clippings indicators) whereas it is only barely on about 90% and that is after you have increased the overall exposure and the whites. Different cameras have different ability to capture highlight detail and your Sony should be excellent in that regard. Underexposing significantly is not good as it will negatively affect the colour and tonal range. It s better to go as far to the right as you can without clipping the highlights and pulling back the detail in LR. The camera histogram is based on the JPEG so spending time on trying to get it right in camera is of dubious value. Just try a series of exposures a stop apart and be aware that if you expose off the flower itself then you will underexpose anyway. For flower photography where colour is critical, a good gray card such as the one by X-Rite is very useful for correctly exposing and later colour balancing in LR. 

Ok, I'm getting confused. Think I need to look at some YouTube videos! So if a colour, e.g. red, rises above the histogram on the right hand side, it's saying that the highlights are mostly formed of that colour? I understand that if the histogram generally, or a particular colour, disappears off the left or right hand side, then it's clipped and I've lost information.

 

Yes the flowers are often very bright so the camera automatically underexposes back to mid-grey, giving an underexposed image. Will try different exposures and different lighting.....

 

p.s. it's interesting the in-camera histogram is based on the JPEG in 'professional' cameras and not the raw file.

 

 

Edited September 13, 2020 by Steve F

[John Richmond]

Red and orange flowers are always a problem in bright sunshine.  It's very easy to over saturate the red channel and lose detail.  White flowers are another problem.  Metering to preserve detail in the white blooms often under exposes the remainder of the image.  For these cases softer light - morning, evening or light overcast = is far better for plant portraits as the dynamic range is reduced and the chances of clipping are far less.  I do shoot in bright sunshine on occasion but rarely for close up portraits of bright red, orange or white flowers, more for general shots with combinations of plants and here a polarising filter is very useful to cut down glare on foliage and the more reflective flowers.  I rarely use flash in the field for my total illumination but I do use fill flash on occasion for against the light shots.

 

For example:

 

Orange rimmed red flower of the half-hardy annual, Tagetes linnaeus.  Taken in softer light to preserve detail in the petals and provide a balanced foreground/background shading.

 

 

Elegant red centered white flowers of the hardy small ornamental tree, Magnolia x wieseneri, taken again in softer, diffused afternoon light

 

 

I used a polariser for this view of the sunken garden at The Garden House to avoid problems with the bright yellow of Hakonechloa aurea 'All Gold' center left.

 

 

Fill flash was useful for these two backlit portraits of Eucomis comosa and Lavandula stoechas 'Anouk' in my own garden.  Both taken against evening sunlight, hence the darker backgrounds.

 

         

 

The alternative is to take the flowers or plants indoors for studio shots - but that's another story.  (Though the results can excellent even with minimal equipment):

 

[MDM]

30 minutes ago, Steve F said:

Ok, I'm getting confused. Think I need to look at some YouTube videos! So if a colour, e.g. red, rises above the histogram on the right hand side, it's saying that the highlights are mostly formed of that colour? I understand that if the histogram generally, or a particular colour, disappears off the left or right hand side, then it's clipped and I've lost information.

 

Yes the flowers are often very bright so the camera automatically underexposes back to mid-grey, giving an underexposed image. Will try different exposures and different lighting.....

 

p.s. it's interesting the in-camera histogram is based on the JPEG in 'professional' cameras and not the raw file.

 

 

 

Actually Steve I might be wrong about the in camera histogram in general. What I said is true for Nikon cameras - they use an embedded JPEG file for the histogram and not the raw file. But it may not be true in the general case. You would need to check for your camera. However, that said, I prefer to shoot first and worry about getting the details right in post. I very rarely get it too far wrong and if I am in doubt  I will use a few different exposures. The Nikons (and the Sonys) have such good dynamic range that checking the histogram in camera is not something I do. But a good gray card can be invaluable. 

Edited September 13, 2020 by MDM

[MDM]

20 minutes ago, John Richmond said:

Red and orange flowers are always a problem in bright sunshine.  It's very easy to over saturate the red channel and lose detail.  White flowers are another problem.  Metering to preserve detail in the white blooms often under exposes the remainder of the image.  For these cases softer light - morning, evening or light overcast = is far better for plant portraits as the dynamic range is reduced and the chances of clipping are far less.  I do shoot in bright sunshine on occasion but rarely for close up portraits of bright red, orange or white flowers, more for general shots with combinations of plants and here a polarising filter is very useful to cut down glare on foliage and the more reflective flowers.  I rarely use flash in the field for my total illumination but I do use fill flash on occasion for against the light shots.

 

 

 

Great advice John. I am with you on the polariser. Not only does it cut glare but it can give purer, more naturally saturated colours. The drawback is it cuts down the light by a stop or two.

Edited September 13, 2020 by MDM

[Steve F]

25 minutes ago, MDM said:

 

Actually Steve I might be wrong about the in camera histogram in general. What I said is true for Nikon cameras - they use an embedded JPEG file for the histogram and not the raw file. But it may not be true in the general case. You would need to check for your camera. However, that said, I prefer to shoot first and worry about getting the details right in post. I very rarely get it too far wrong and if I am in doubt  I will use a few different exposures. The Nikons (and the Sonys) have such good dynamic range that checking the histogram in camera is not something I do. But a good gray card can be invaluable. 

It's the same for Sony, A7iii at least. I never use my in-camera histogram; now I feel vindicated 😅

[Steve F]

45 minutes ago, John Richmond said:

Red and orange flowers are always a problem in bright sunshine.  It's very easy to over saturate the red channel and lose detail.  White flowers are another problem.  Metering to preserve detail in the white blooms often under exposes the remainder of the image.  For these cases softer light - morning, evening or light overcast = is far better for plant portraits as the dynamic range is reduced and the chances of clipping are far less.  I do shoot in bright sunshine on occasion but rarely for close up portraits of bright red, orange or white flowers, more for general shots with combinations of plants and here a polarising filter is very useful to cut down glare on foliage and the more reflective flowers.  I rarely use flash in the field for my total illumination but I do use fill flash on occasion for against the light shots.

 

John, thanks a lot for posting these images. Yes, I had noticed photographing white flowers can also be a pain. It's great to see the range of techniques for different flowers and lighting conditions. Now, where is my polariser.....

Edited September 13, 2020 by Steve F

[M.Chapman]

9 hours ago, Steve F said:

Could be. I'm working in Adobe RGB and don't softproof in sRGB...

Yes. If you want to see a potential source of problems, try this on one of your images with a red channel that's close to saturated (as seen in the LR histogram). Export sRGB and AdobeRGB jpg versions of the image from LR. Now open those images in PS and look at their histograms. Note how the red channel may have become clipped.

 

AdobeRGB

 

 

sRGB

 

Because Alamy convert to sRGB (even if the contributor submits in AdobeRGB) this is a potential problem that it's worth being aware of. Soft proofing is a good way to anticipate problems and correct them before the image is converted to sRGB. Unfortunately soft-proofing in PS doesn't update the histogram display. If you use soft proofing in LR, set the destination to sRGB to see the effect on the histogram and then toggle the out of gamut warning to see affected areas of the image (I think that's how it works anyway).

 

Interestingly, in PS ACR the histogram does update in line with the export colour space settings you select. I find this very useful when setting sRGB as the working colour space in ACR preferences.

 

Mark

Edited September 14, 2020 by M.Chapman
Correction it's the histogram in PS that doesn't update.

[MDM]

Mark . Not clear what you mean there. Changing the output profile in LR soft proofing (the dropdown at the bottom of the histogram) or making changes to any of the development parameters does update the histogram. As far as I can recall it always has done as well as I use this a lot for printing to different profiles and the histogram is important here. 

[M.Chapman]

9 hours ago, MDM said:

Mark . Not clear what you mean there. Changing the output profile in LR soft proofing (the dropdown at the bottom of the histogram) or making changes to any of the development parameters does update the histogram. As far as I can recall it always has done as well as I use this a lot for printing to different profiles and the histogram is important here. 

I must be doing something wrong then. I’ll take a look tomorrow.

 

Mark

 

Update: You're right. My mistake. It's the histogram in PS that doesn't update, LR is fine. The image also shifts by more than I'd expect in PS when soft proofing to sRGB. I'm not sure what's going on with soft-proofing in PS. PS ACR is fine though, the histogram and image change correctly according to the colour space selected in ACR preferences. I've  corrected my earlier post. Thanks!

Edited September 14, 2020 by M.Chapman

[Bill Brooks]

The in camera histogram is read from the extra small JPG file made for the RAW file header. This header JPG is made from the camera's JPG settings acting on the RAW info, but does not capture all of the info in the RAW file.

 

I only shoot RAW, and so I have the camera's JPG settings set as bland as possible. Everything in the camera JPG settings turned down, shoot in Adobe RGB. This bland setting produces a camera display JPG, and the camera histogram from it, close to the unprocessed raw. So now the in camera histogram, although read from the bland camera JPG settings, is very close to the information in the RAW file.

 

I still get a slightly misleading JPG camera histogram, but it is only slight, and I can usually mentally adjust for it in order to get individual RAW colours at no more than 254, when necessary.

[spacecadet]

Time to dust off the flashgun and mini-softbox maybe!

I've just got some very yellow chrysanths in and they are very sensitive to white balance which I usually forget to change from auto. No problem in RAW of course but having it right first look is nice.

This is the straight RAW, just default NR and sharpness. I don't think I've ever posted unprocessed before.

I note that LR flash WB is 5500K but the A58 and Sony Remote sets it to 6250K and tint+15. A bit more orangey.

Edited September 15, 2020 by spacecadet

[DDoug]

To solve a problem such as Steve described, or to change the overall appearance of an image, I sometimes use channel substitution.

 

For example: select and copy the green channel; convert to LAB color; select Lightness channel and paste the green channel; convert back to RGB color. This yields an image which has the same colors as before, but with the tones such as they would be on a black and white photo shot with a green filter.

 

Similarly, a sky can be made more dramatic by using the red channel. Sometimes this works well and sometimes it's awful. Fun to experiment with in any case.

 

edit: Coincidentally there was bright sunlight on a yellow Johanniskraut flower in the back yard this afternoon, so I made a sample including the basic shot, modified with the green channel and also with a mix of green and blue channels.

Edited September 16, 2020 by DDoug
add image

[Bill Brooks]

4 hours ago, DDoug said:

To solve a problem such as Steve described, or to change the overall appearance of an image, I sometimes use channel substitution.

 

For example: select and copy the green channel; convert to LAB color; select Lightness channel and paste the green channel; convert back to RGB color. This yields an image which has the same colors as before, but with the tones such as they would be on a black and white photo shot with a green filter.

 

Using LAB is a new one for me. I have always used all RGB swap with less control. Thanks DDoug I am going to try it.

 

If you want to make big colour changes without affecting the neutral and other colours, swap channels in RGB only.

 

This green maple leaf original was turned to red, by swapping the Red and Green channels. In such a swap any neutral colours or other colours will remain neutral or the same because there is very little difference between channels in neutral colours. Notice the blue colour at bottom left has not changed very much from the top original, only the green

 

 

[Betty LaRue]

It turned from blue to purple, pretty big change to my way of thinking. But such a small area of the image it’s easy to ignore.

[wiskerke]

34 minutes ago, Betty LaRue said:

It turned from blue to purple, pretty big change to my way of thinking. But such a small area of the image it’s easy to ignore.

 

 

Without words.

(We men that is.) 😁

 

wim

[Betty LaRue]

36 minutes ago, wiskerke said:

 

 

Without words.

(We men that is.) 😁

 

wim

Funny.  Maybe Bill is blue/purple challenged.
Pretty far apart on the color wheel. Erm..stick, erm.. ruler... Actually, blue & red makes purple.

I can certainly understand how messing with the red channel would turn blue to purple. Doing whatever was done in layers and brushing out that change would fix it.  Would need done in PS or any software having layers capability. I haven’t done much with layers recently, but did a bunch of it in the past.

[John Mitchell]

Glad to hear that others are seeing purple. I was worried that it was my monitor.

 

Being severely PS-challenged, I avoid photographing flowers in direct sunlight. Cloudy days or light shade work best for me.

 

Also, I prefer to wait for Mother Nature to do the colour changes. She's pretty good at it. 🍁 😁

 

 

 

 

Edited September 16, 2020 by John Mitchell

[DCSmith]

Try a UV filter on the lens as well. 

Certain flowers reflect a great deal of UV which the eye can't see but the camera can pick up.

Infrared is also a potential culprit.

Modern sensors are usually pretty good at blocking non visible wavelengths, but some do manage to sneak through.

I did some photography for 1800flowers back in the 80's when they were a startup and we had to have local color correction done on certain flowers  by a retoucher (pre digital) because film couldn't record their color correctly.  Happens with certain paint pigments as well.

Edited September 19, 2020 by DCSmith