Just a cactus

Images taken in a controlled environment or with a posed subject. All subject types.

Moderators: rjlittlefield, ChrisR, Chris S., Pau

DaveW
Posts: 1702
Joined: Fri Aug 04, 2006 4:29 am
Location: Nottingham, UK

Just a cactus

Post by DaveW »

Echinocereus baileyi Taken solely to record this years flowering.

Image

DaveW

rjlittlefield
Site Admin
Posts: 23561
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

Now that's a lovely flower! :D

Beautiful color & gradation in the flower.

I'm puzzled by the background, though. There's a pattern of "ripples" to the left of the flower that doesn't look like any artifact I'd expect here. I'm thinking those might be folds in dark fabric used as a backdrop. But there are also large blocks of noise that are way too big to be jpeg artifacts. I don't have a clue what causes those. Do you have any ideas? Did this image go through any software other than Photoshop or similar?

BTW, the ripples and blocks might be invisible, depending on how your monitor is set up. If you can't see them, try brightening up the image in Photoshop.

--Rik

DaveW
Posts: 1702
Joined: Fri Aug 04, 2006 4:29 am
Location: Nottingham, UK

Post by DaveW »

Yes it is black velvet Rik and the ripples do not show on my monitor. The blocks may be where I removed grains of sand on the background using the Healing Brush Tool in Photoshop Elements to generally clean up the background?

DaveW

DaveW
Posts: 1702
Joined: Fri Aug 04, 2006 4:29 am
Location: Nottingham, UK

Post by DaveW »

So far it's 50% - 50% Rik when I posted it elsewhere. You and another can normally see problems on their monitor and another two can not, or three if you include me. One comments he sees pixelation and marks them, but I cannot normally detect them on my monitor. He has now enhanced it and I think it may be my use of the Healing Brush in Elements you are both seeing, but normally it does not show on my monitor. See:-

http://www.tipf.org.uk/forums/index.php ... entry40204

Is that what you are seeing Rik?

DaveW

lauriek
Posts: 2402
Joined: Sun Nov 25, 2007 6:57 am
Location: South East UK
Contact:

Post by lauriek »

I can see what Rik's talking about as well, although I just got a new monitor and I think it might be set a bit bright at the moment!!

Nice pic though! Love the little green bits in the middle of the flower, is that the stigma?

rjlittlefield
Site Admin
Posts: 23561
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

Yes, the big blotches of pixel-level noise that are obvious on the enhancement. The ripples are not much more obvious in the enhancement than they are in the original view, on my monitor.

If you're seeing that background as black or nearly so, then your monitor is set way different from mine. On mine, it's dark grayish. Photoshop reports a mean value of around 30, with a distinct color cast -- the mean value for blue in the background is about 42, for red it's only 22.

One technique that works well with images like this is to pick some values out of the real picture, use those to paint a gradient on a new layer, then use a feathered mask around the subject to show the smooth gradient except very close to the subject. It takes some practice to make an invisible transition from real background to gradient, but the effect is nice once you've got it down.

Another trick that I use frequently when editing dark backgrounds is to slap on an adjustment layer to brighten it up a lot, like your friend's enhancement. Then after I'm done editing, I turn off the adjustment layer before saving to jpeg. That leaves me pretty sure that people won't see my edits, no matter how they have their monitor set.

One final trick that helps to see irregularities in backgrounds is to slide the image around the screen. Moving patterns are easier to see than fixed ones, especially if they're low contrast and fuzzy.

None of this matters, of course, if you're just out to record the flower, and all of them can be applied later anyway. I was just curious...

--Rik

DaveW
Posts: 1702
Joined: Fri Aug 04, 2006 4:29 am
Location: Nottingham, UK

Post by DaveW »

The background is dead black on mine and the monitor is still set as the makers set it out of the box since when I used the following test it seemed reasonable, but perhaps the 0% and 10% squares don't show much difference, though there is some just discernible. What do I do turn up the brightness a little? I am using a Dell 24" flat panel monitor.

http://ludens.cl/photo/montest.html

I presume you are setting your monitor with Spyder or something similar?

The background was black velvet but of course in full light on a sunny day often shows some texture and imperfections which need spotting out in PP. I will probably have to come up with some method of shading it to try and get it blacker at the taking stage.

Yes the green bits are the stigma lobes and are characteristic of Echinocereus in that there are only a couple of species that are a slightly different colour.

DaveW

rjlittlefield
Site Admin
Posts: 23561
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

No, I don't have anything like Spyder. Currently my monitors are all running as out-of-the-box. I used to have one custom profile that matched a calibrated printer, but it rotted a couple of weeks ago when I replaced the graphics card.

All of my monitors (three different types tested just now) show a clear distinction between 0% and 10% on the monitor test you link. Two of the three also show gray background with obvious ripples & noise on the cactus image; the third shows a very dark gray background where ripples and noise are visible with study but would not be noticed otherwise.

What to do to turn up the brightness depends heavily on exactly what type monitor you have and how you are driving it. Many of the Dell monitors have on-screen menus with brightness and contrast controls operated by buttons. One of my Samsung monitors has nothing more than a power button; I would have to use some software to adjust that one.

--Rik

Aynia
Posts: 724
Joined: Thu May 01, 2008 7:42 am
Location: Europe somewhere
Contact:

Post by Aynia »

The background is a dark dark grey to me - not unattractive. I was too busy looking at the lovely flower to notice any imperfections.

Dave, have you tried out different background colours - I'm thinking desert type colours, green or sandy - something a bit more 'natural' than black.?

DaveW
Posts: 1702
Joined: Fri Aug 04, 2006 4:29 am
Location: Nottingham, UK

Post by DaveW »

I have tried other backgrounds Anyia but was not too keen on them. Black tends to produce the "3D" effect when projected, as all my cactus shots are intended solely for web use or digital projection at my cactus societies monthly meetings. I understand monitor screen and projection screen resolution is about the same. Obviously different criteria apply if you are printing out.

Given the comments regarding viewing text in the link I gave Rik, I wonder if Dell made a compromise setting so text on white backgrounds was not too glaring?

Dell give my monitor in their invoice as FP/BL - UK/IRISH Wide Flat Panel 2407FPW 242 (TCO99) Ultrasharp (DVI-D) Black. See:-

http://www.bit-tech.net/hardware/2006/0 ... P_monito/1

Obviously if my monitor is producing dark grey as black it will upset my PP assessment if it is to be seen on other monitors with the brightness turned up higher.

Will see what I can do.

DaveW

lauriek
Posts: 2402
Joined: Sun Nov 25, 2007 6:57 am
Location: South East UK
Contact:

Post by lauriek »

I just got the new version of that monitor, the 2408 - it's fantastic! Was exceptionally bright out of the box, I still have my old CRT here on another box, and it's so dull by comparison it looks broken! I've tweaked the brightness down a bit and I can still see the glitches in the background, I think you might want to brighten your screen up a little..

I use one technique Rik mentioned in pretty much the same way:

I create a curves adjustment layer, and use that to brighten up the image so that you can see the detail in the background (or darken if your background is very bright), at this point don't worry about the fact the detail in your image is blown right out, the layer is only temporary.

Note at this point if there is a lot of noise in the background I normally use Neatimage to reduce that at this stage then start this process again with the new noise reduced image..

Then I go back to the main image layer, edit out anything I can see in the background with the clone tool, then when I'm happy I turn off the adjustment layer and save.

Then as Rik says, no matter what relative brightness the image is being viewed with the background should at least always look clean...

rjlittlefield
Site Admin
Posts: 23561
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

That's a lovely monitor! Substantially higher resolution than any projector you're likely to encounter, BTW.

It appears from the online illustrations that there are 6 physical buttons at the lower right of the display bezel. On every Dell monitor that I know, one of those buttons will get you into an onscreen menu, which can then be navigated using the other buttons. The menu allows to adjust brightness, contrast, color balance, and numerous other options that you probably won't have any reason to touch.

--Rik

DaveW
Posts: 1702
Joined: Fri Aug 04, 2006 4:29 am
Location: Nottingham, UK

Post by DaveW »

There is another monitor calibration web site here:-

http://www.drycreekphoto.com/Learn/moni ... ration.htm

The interesting statement in the above link is:-

"The brightness should be set so almost black is just barely distinguishable from pure black. Set brightness too low, and all your shadow details go dark. Set too high, the shadows get washed out."

As I said earlier almost black is just distinguishable from black on my monitor on the first monitor calibration link I posted. I can perhaps get away with brightening a bit.

DaveW

Aynia
Posts: 724
Joined: Thu May 01, 2008 7:42 am
Location: Europe somewhere
Contact:

Post by Aynia »

DaveW wrote:I have tried other backgrounds Anyia but was not too keen on them.
I thought you probably did! Another background colour would stop this discussion dead in its tracks as we'd all be seeing a slightly different shade of something else...

Of course then I wouldn't be learning about all those different monitors. :D

rjlittlefield
Site Admin
Posts: 23561
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

Dave,

Those two monitor test sites that you've linked are quite different.

At http://ludens.cl/photo/montest.html , the box labeled "10%" displays as RGB=26.

Contrast this with http://www.drycreekphoto.com/Learn/Cali ... _black.htm which says that "A top quality monitor using an excellent calibration system can show the difference between levels 0 and 1. Average monitors will not show any increase in output until level 5 to 8", and by "level 5", it really does mean RGB=5.

The three monitors I just tested are all on the good end of Dry Creek Photo's scale, first starting to show gray at RGB=4 in a dim room. It's interesting to note however that they don't all have the same curves. At RGB=20, one of the three is significantly darker than the other two, even though it starts and ends at about the same black and white.

The Dry Creek test seems to be well structured and to have good recommendations.

--Rik

Post Reply Previous topicNext topic