Monster spider and posterizeing problem on D80

First of, can anyone help me identify this spider? It was in my garden and it is a monster! Well... OK... only ± 1" I would guess, but it did create a several feet long line for her web.

Second, as you can see, I have some serious posterizeing problems in the shadows. It was accentuated by making a JPEG for posting, but it is there in the NEF file as well

Any idea of what can cause this? Just a matter of not having enough bit depth (even at 12 bit?).

I am sure that the flash did not help, but the speed + ISO + ƒ stop were reasonable considering there was plenty of natural (sun) light.

CC always welcome too.

D80; ISO 200; Tamron 90 ƒ 2.8 @ ƒ 16; -0.5 EV; SB-800 @ -0.5 EV.







--
Lito
D80 + Mac



Bombing for peace is the same as f_ g for virginity

Looks like a Common Garden Spider, they are sometimes mistaken for a Wolf Spider. I get some big ones in my garden, creepy.

Patrick
D80
http://peters.zenfolio.com
http://picasaweb.google.ca/Patrick.D80.P850/WhatISee

Very nice. Nocturnal garden orb-web spider. One of a large number of subspecies, they are nice spiders (shy), not poisonous but have been known to cause heartfailure when people walked into their webs at night and the spider crawled about a face or dropped down a shirt.

I spent a bit of time last night shooting one with my Tamron 90.
--
Purely a hobby.

--



http://leungphotography.smugmug.com

LitoD80 said:

Second, as you can see, I have some serious posterizeing problems in
the shadows. It was accentuated by making a JPEG for posting, but it
is there in the NEF file as well

Click to expand...

Hard to see at this size, I think you mean the pink and green areas.

It may be due to sharpenning in which case selective sharpenning will fix it.

Most likely caused by the way you saved the JPG for example if have a gradient accross blue sky shot with a wide angle lens and I save the JPG in NX using a lower quality like 'Good or HIGH compression ratio' then I get seriuos visble steps instead of the nice gradient.

Open your original JPG and compare it to your saved JPG that will tell you if the problem is the way you saved it.

LitoD80 said:

Any idea of what can cause this? Just a matter of not having enough
bit depth (even at 12 bit?).

Click to expand...

12 bits when you shot it, only 8 bits in JPG and less if you saved it in a way to minimize file size at the expense of image quality

--
Inspector Kluso

Sorry about the pun. My orb weavers in my garden seem to get creepier during the season. Personally, I think they are cute in the beginning, but by the end of the season, they get kind of bulgy looking.

I've been told not to worry about the posterizing (didn't know what it was called until now), but it does bother me. On the other hand, if you didn't mention it, I wouldn't have noticed. What I've never tested is to see if the photo is affected in print.

jpeg compression handles edges well, but doesn't do smooth well (at least from what I've read and tried). Also, while we think Jpeg is a uniform standard, it is not. I'm pretty sure every manufacturer uses a different compression matrix (I think that's what its called). I've done some test shots w/ my D80 and find that if the picture is properly exposed the posterizing does not show up as much. On the other hand, at -1 stop it starts to show up when I'm digitally adjusting the exposure. I think that is, as you pointed out, because you've squished your bit depth down. You might be shooting at 12, but since you are not properly exposed (in the black areas), you are only using 6 or 8 bits.

Another factor is the quality I apply to the jpeg (eg. fine to basic). It is really not evident to any great extent in fine, but its all over the place in basic. This is especially true if the subject is black or I shoot in higher iso.

Here's a composite of a number of test shots. I gathered these pictures into a single photshop file from the jpegs at 1:1. I never thought to look into the raw files (NEF are compressed as well). I guess that's next . I exported the final image using png since it does not compress. I should point out that there is a small amount of variation in the glossiness of the calculator which you see in both Medium and Fine.



By the way, if I'm way off base, feel free to tell me (be nice).

Kirk

Creepy indeed!
--
Lito
D80 + Mac



Bombing for peace is the same as f_ g for virginity

I'd like to see some of your images if you get the time! Would be good to see how different eyes with the same gear look at the same subject.

--
Lito
D80 + Mac



Bombing for peace is the same as f_ g for virginity

--
Lito
D80 + Mac



Bombing for peace is the same as f_ g for virginity

The images are all from NEF (RAW files). The posterizeing is there even when opened in NX... But you are right; hard to distinguish at this size.

--
Lito
D80 + Mac



Bombing for peace is the same as f_ g for virginity

Great examples! Thank you for posting them.

Yes, I know the D80 compresses the NEF file (as opposed to the D200). The difference must reflect someplace, right?

I am mostly bothered because when you try to recover details from shadows is when the effect becomes most obvious.

In the images of the spider is no biggie of course, but when I have a good shot that just need some PP in the shadows, even if well exposed for other areas, then it kills me.

I guess HDR is a solution for when you have a huge dynamic range, but on daylight shots with fill flash...

Well... Start saving for a D90 I guess

--
Lito
D80 + Mac



Bombing for peace is the same as f_ g for virginity

I have one of those spinning her web across my porch steps every night right now. She seems very optimistic about bagging me eventually.

--
Roscoe

Today I took my car out for the first time in a week. I noticed as I was cruizing down the Queensway that one had made a web between my Thule box and my windshield wiper. 100km wind didn't budge him - he's still there.

Here's one on my front porch... they do get big.



Richard

LitoD80 said:

The images are all from NEF (RAW files). The posterizeing is there
even when opened in NX... But you are right; hard to distinguish at
this size.

Click to expand...

In that case what you are seeing is noise from trying to push dark levels too far, to a degree you are going to see that on all DSLR.

Try overexposing slightly rather than underexposing as you can recover more easily a slightly overexposed [at least 1 stop is easily recovered from NEF by NX] area than underexposure.
--
Inspector Kluso

LitoD80 said:

Great examples! Thank you for posting them.

Yes, I know the D80 compresses the NEF file (as opposed to the D200).
The difference must reflect someplace, right?

I am mostly bothered because when you try to recover details from
shadows is when the effect becomes most obvious.

In the images of the spider is no biggie of course, but when I have a
good shot that just need some PP in the shadows, even if well exposed
for other areas, then it kills me.

I guess HDR is a solution for when you have a huge dynamic range, but
on daylight shots with fill flash...

Well... Start saving for a D90 I guess
will be very popular

Click to expand...

A D90 will not help. If you underexpose and then push the shadows you can get this as well as increased noise in those darker areas. When you push the shadows you increase the gain in the darker areas, spreading the difference between the consecutive binary steps of the original, hence posterization. This can happen on a D300 as well as a D80, so save your money and work on exposure and lighting. OK, so find yourself another spider and get to work
--
Stan ;o()



In the spirit of Occam’s Razor one should embrace the less complicated formulation or simply put, less is more.
http://standavidson.com/post/Birds

Lovely lady (?) in these pictures!

Last one is my favorite. Black/green background and spider hanging in a single line. Very nice! Other two might be better with more light and contrast?

Best regards,

--mikko--

Hi,

See the excelent ( IMO) Ron Bigelow website ( see articles section ) about the 14 bit advantages and posterisation problem:

http://www.ronbigelow.com/articles/bits-1/bits-1.htm ( part 1 )
and
http://www.ronbigelow.com/articles/bits-2/bits-2.htm ( part 2 )

You can find very interesting general photography articles on Ron Bigelows website : http://www.ronbigelow.com/articles/articles.htm ( also about using photoshop )

As another person in this thread suggested , the solution to your problem is IMO : shoot RAW "overexposing" a bit ( about max 1 stop can be recovered in PP ). This way you have max information in the darker parts of your picture, wich should diminue the posterisation effects.

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Greetings,
Marc



my photos (under construction):
http://www.flickr.com/photos/mrbr03/

is it halloween already? those spiders make the hair on the back of my neck stick up. looks like a prime candidate for the slipper treatment.

cool info on the posterizing.
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SophieZ

Thank you all for the compliments and the good advise.

Indeed, you are all correct when you tell me of the results one can expect when pushing the dark areas.

This said, I just realize (now in my office), that the calibration of my monitor at home must be way off. I have the same monitor at both ends, but only the office gets calibrated once a month.

It is very possible that the monitor at home needs fine tuning, as the images here do look way darker in the shadows and this display was calibrated last week.

Thank you also for the samples! Yup... That is the same spider. 100 clicks eh?... Must be the fastest spider in Canada

--
Lito
D80 + Mac



Bombing for peace is the same as f_ g for virginity