Ahh Choo!!! It's allergy season!

[Ed Vatza]

Fortunately no pollen allergies for me. Even my wife commented that she can't remember a year that there was so much Goldenrod around. It seems to be everywhere. So I thought I take advantage of its abundance to make some images. I just wish the leaves weren't as chewed up as they are.

I am really curious about your thoughts here. I have made many Goldenrod images over the past week or so and have junked most of them. Focus is very difficult since they reach out in all directions. And the yellows seem to oversaturate badly. I desaturated the yellow in this image but am not sure I backed off enough. Thoughts?

Canon Rebel XT; Sigma 150mm Macro lens; Canon 430 EX Flash with LumiQuest Softbox; Tripod-mounted with Novoflex focusing rail.

1/30 sec @ f/11; ISO 800; ISO -1/3; Shade WB; FEC -1

[Julie Kenward]

Hahaha...I see you've met my nemesis! For as much goldenrod that's around I have had a pretty mild allergy season (so far...knock on wood) but I've been trying to photograph this plant as well and it's H.A.R.D.! You said exactly what I've been experiencing - only part of the image is in focus and the yellows! Yikes!

I think you're really close on this one but they do still seem a bit saturated. You did manage to get about 90% in focus and the other 10% you have to really look for it so I think you did really well there. Maybe I'll give it another try when I'm out today...

[Ed Vatza]

Thanks Jules. I wasn't sure if I had desaturated the yellows enough. But I was chicken to go any farther. Now here is a second version where I have desaturated just a little more. I'm trying to strike that perfect balance.

[Anita Rakestraw]

Hi, Ed, certainly agree with the difficulty of photographing these!! Not sure if I've kept any of my attempts either! I think both your posts look fine for the saturation; I can hardly tell the difference but it may be my monitor. Have you checked for oversaturation on the histogram? I'm no expert on determining saturation from the histogram, but looking at these in PSP (which I use mostly) it looks like the reds are oversaturated...?? Does anyone use the histogram to determine proper saturation??

[Robert O'Toole]

Ed, Image looks great, I like the cool shape of the plant. DOF looks great and best of all the light is nice and soft.

I prefer the repost. Sat doesnt look too bad now. Yellows and reds are difficult in SRGB color space.

Did you or anyone notice the white crab spider hanging under on the right? Cool image there also!!!!!!

Robert

[Robert O'Toole]

Hi, Ed, certainly agree with the difficulty of photographing these!! Not sure if I've kept any of my attempts either! I think both your posts look fine for the saturation; I can hardly tell the difference but it may be my monitor. Have you checked for oversaturation on the histogram? I'm no expert on determining saturation from the histogram, but looking at these in PSP (which I use mostly) it looks like the reds are oversaturated...?? Does anyone use the histogram to determine proper saturation??

Yes its easy Anita.

Open image in PSCS3.

Press Ctrl+M for curve and press show clipping.

Or

Press F8 for info/histogram. Select Histogram tab behind info tab.

Click the little triangle in the right corner for the options menu.

Select all view + show all channels in color.

Also there is a gamut warning under menu>view if you have a printer profile selected.

Robert

[Mike Moats]

Hey Ed, I see a lot of golden rod when I'm out, but haven't tried shooting it. The flowers are so tiny and clustered that it would be hard to get a image where you can detect the flower heads. The yellows as you say are tough to work with. Hope you closed in on that sprider and give it a try. These flower heads are very deep so it take a lot of DOF to get them in focus so you did well while still maintaining a soft BG.

[Anita Rakestraw]

Yes its easy Anita.

Open image in PSCS3.

Press Ctrl+M for curve and press show clipping.

Or

Press F8 for info/histogram. Select Histogram tab behind info tab.

Click the little triangle in the right corner for the options menu.

Select all view + show all channels in color.

Also there is a gamut warning under menu>view if you have a printer profile selected.

Robert

Thanks, Robert!

[Ed Vatza]

Thanks everybody! As always, I appreciated the comments and critiques. The yellows are certainly a bear for me to deal with. And I was having nightmares about trying to get the dof right here. I think I am close on this image.

The Goldenrods caught my attention mostly because of their color and the kind of randomly flowing shapes that they take. I wouldn't even think of trying to focus in on showing the detail of a single flowers... unless I had something like the Canon MP-E65 which I don't.

[Chris Starbuck]

Ed,
I know I'm a week behind everyone else (I've been offline quite a while), but since Goldenrod blooms for quite some time I thought I might still offer a little help.

Everyone else has offered good comments, with which I pretty much agree. I think your composition is fine, and the DOF is sufficient (even though I tend to obsess over DOF). I love finding "bonus bugs" in flower images (and you have two!); I think they add a lot of interest and tell more of a story than just an isolated flower portrait.

On the DOF issue, you were so close to covering the whole flower head at f/11 that I think f/16 might have covered it all, or very nearly, without unduly focusing the background. Of course if you were already struggling with air movement at 1/30 sec, 1/15 sec might have driven you completely nuts, except for my next comment below. An alternative approach is to go for a very shallow DOF, but that's a very different sort of image.

The root of the "oversaturation" problem is that the XT and many other Canons (probably others too, since I think it's rooted in a fundamental property of silicon photodetectors -- I'm an electronics engineer, BTW) is that the sensors are much more sensitive to red than to green or blue. The XT and my 20D and a number of other older models only display a composite (luminance) histogram. So frequently when photographing bright highly saturated red or yellow subjects, the overall histogram can look fine, with the right side well away from the right edge, while in fact the red channel is seriously over-exposed, losing all detail. With newer camera models (starting with the 30D) which can display separate histograms for each color channel, you can check the red channel, and adjust exposure so that it's not blown out. With our older models, about the best solution I've found for shooting bright red or yellow subjects is to get the composite histogram to look like you think it should, then reduce the exposure by 2/3 or a full stop. [This will recover most or all of the shutter speed lost by stopping down the aperture from f/11 to f/16.] Of course this will darken the overall image, resulting in more noise when you later lighten the mid-to-dark tones in post-processing to optimize the image, but it's the only way I've found to avoid the complete loss of detail in the bright reds & yellows. If you've exposed normally, then desaturating the red channel in post-processing will make the colors look better, but as with any over-exposure it can't bring back detail that the camera didn't record. So you have (yet another) trade-off to make: noise vs. highlight detail preservation. Try it both ways and see which works better for you.

One final note in defense of the Missouri state flower. ;-) Goldenrod pollen (all species) is so small and smooth that almost nobody is actually alergic to it. Folks who think they are, are much more likely to be reacting to ragweed, which grows in much the same places as Goldenrod, blooms at about the same time, and is one of the worst pollen alergens on the planet -- very large spiky mace-like pollen grains. Ragweed is also nearly invisible unless you know what to look for; the flowers are tiny and the same shade of green as the foliage.

That's my much-less-than-$.02-worth.

Chris

[Robert O'Toole]

Chris you have made some good points especially the info on the Ragweed.



The root of the "oversaturation" problem is that the XT and many other Canons .... is that the sensors are much more sensitive to red than to green or blue. ....With newer camera models (starting with the 30D) which can display separate histograms for each color channel, you can check the red channel, and adjust exposure so that it's not blown out.

This is one of those subjects that when you look into it you and learn more you sometimes decide it was better not to know. :)

First of all the reason for DSLR histogram channel display discrepancies are that the camera adds a red and blue channel multiplier factor of 2x or so. This is to compensate for the fact that DSLR bayer sensors have twice as many green photosites as red or blue. You can easily get around this to get an accurate channel histogram by loading a corrected custom WB. This will give you a strange looking preview thumbnail but will give you a close to perfect histogram that will let you get the most dynamic range possible. For Nikon this is called UniWB.

To overcome the red channel sensitivity some people use a magenta CC filter. I have never bothered to try this one.

Also in this case Ed choose Shade WB, which is very warm 7000K (!). This effects not only the histogram but also the exposure of course since the histogram date is not from the Raw file but the preview JPEG. More accurate WB settings will always give you a better histogram.



With our older models, about the best solution I've found for shooting bright red or yellow subjects is to get the composite histogram to look like you think it should,...Of course this will darken the overall image, resulting in more noise when you later lighten the mid-to-dark tones in post-processing to optimize the image,

Good point. This is important and I always cover this in my workshops. I recommend soft light, good flash balance, and exposing to the right, but not too far to the right to limit visible noise.

Robert