300D Exposure Lattitude

[rchwallace]

Hello All,

New member and first post so go easy. ;)

I am wondering if anyone has the answer or can point me in the right direction for information on the 300D's exposure lattitude. Plus (?) stops and Minus (?) stops.....

I know this may be info which is not really as important when shooting digital but I would still like to see if I can find the stats as it will none the less help.

Cheers

Ron

[tim]

And if someone could explain the question to me, that'd be great too ;) I guess the question is about how much dynamic range the sensor can capture, which I have no idea about.

[Dante King]

That would have to do with the lens attached for F/stops i beleive.

[Olegis]

You can run a very simple test to find out how much dynamic range your sensor has. Find a wall with some clearly visible texture, the color of the wall has to be as neutral as possible. Set your camera on a tripod and take the first picture according to the camera meter reading, which would correspond to 18% gray (write down the shutter speed and the f-stop combination). Then set your camera to manual mode and take 10 more pictures, decreasing the exposure by one stop in every picture (either by closing down the aperture or by setting faster shutter speed). Return to the 18% gray setting and repeat these 10 pictures, while increasing the exposure by one stop in every picture.

Review the pictures on your monitor (the computer one, not the camera LCD !) and see when the texture starts to disappear (it would happed when it will be too dark or too light). Note how many stops from the neutral 18% gray the texture is still visible - that would be your dynamic range.

[Monito]

Hello All,

New member and first post so go easy. ;)

Welcome to CDPF!

[ron chappel]

I've done the same test as olegis describes with a result of about 5.5 stops of available dynamic range - 6.5 at a stretch
...or about 7.25 if you want to count individual bright or dark pixels as some of the camera manufactures must do to come up with their silly claims;) :rolleyes: :rolleyes:

Oddly i didn't see much improvement when doing the same test in RAW mode,but i assume that this is due to me not 'pushing' the raw pic in post processing as its is claimed is possible(??)

By the way Ron ( cool name that!;) ) -the phrase 'exposure latitude' is not used much anymore which is probably a very good thing.It was used to describe how far a film could be pushed or pulled....but simply didn't take into account the brightness range of the scene so was allways a stupid half baked idea

These days 'Capturable brightness range' or 'dynamic range' are good phrases to use.
Just be carefull though.Dynamic range also means bit depth in the digital world

[gcogger]

I believe that if you do this 'wall test' in RAW (process to 16bits/colour), then use Photoshop Curves or the Shadow/Highlights tool, you'll find that there's detail way down in those shadows :)

[tim]

RAW is only 12 bits, it's padded to 16 bits for photoshop if you choose the 16 bit option.

[robertwgross]

Is dynamic range the original poster's question?

---Bob Gross---

[rchwallace]

Hey Everyone........ Thanks for the replies.


Great suggestion by the way with regards to using the camera to sort out my answer. I should of thought of that. For a little background on where the question came from.......

I am studieing a course in Photography which is currently reviewing film and its characteristics and how this applies to how one takes photos. The question was based in that with film (my understanding) there is a "lattitude" or as mentioned a "dynamic range" which basically means how many F/Stops the film can see. As we all know the eye can see a huge "dynamic range" and the film or now the CCD/CMOS can only see a much smaller range of that. So in the course they recommend a shooting technique which by knowing how many above and below your (I will just use sensor for this forum) sensor can read they you know where you should put your exposure to maximise the "dynamic range". Now in practicallity I am not sure that this is really going to be much of a factor, esspecially since I am shooting in RAW about 99% of the time and can make some fine adjustments to the exposure but for the "perfect" exposure it may help to knwo that in a high contrast scene.... if I underexpose the shot by about 1 to 2 stops then the sensor will have enough details and ability to capture lets say... -2 to +6 as indicated by the above experiment. Which would be 8 stops..... which I believe is quite a bit more than most film these days but I could be wrong.

So I will definintely run the experiment.... and with your suggestion I will also add the exposure in the oposite direction.... in the underexposure direction.

Thanks to Monito for the welcome message and to everyone for there suggestions. I leave for Cambodia tomorrow but if I can I will upload my results from the test here before I leave.

I will also update my profile but if anyone is interested here is my web site:
http://www.ronhayes.com

Best Regards

Ron

[rchwallace]

decreasing the exposure by one stop in every picture (either by closing down the aperture or by setting faster shutter speed). Return to the 18% gray setting and repeat these 10 pictures, while increasing the exposure by one stop in every picture. .

Hope this works...... Thanks Olegis, I just noticed you recommended to go in both directions.

[rchwallace]

...but simply didn't take into account the brightness range of the scene so was allways a stupid half baked idea

These days 'Capturable brightness range' or 'dynamic range' are good phrases to use.
Just be carefull though.Dynamic range also means bit depth in the digital world

Thanks Ron.....

[slejhamer]

if I underexpose the shot by about 1 to 2 stops then the sensor will have enough details and ability to capture lets say...

Yes ... sort of. One problem you may find is that an underexposed shot, when adjusted in post-processing, can show more sensor "noise," especially in the shadow areas, than a similar shot that is slightly overexposed and later toned down.

This article might be of interest to you:
http://www.luminous-landscape.com/tutorials/expose-right.shtml

Rather than arbitrarily underexposing a high-contrast scene by a set amount, the old advice of exposing for the most important highlight might be a better approach.

Very nice photo gallery, by the way. :)

[rchwallace]

Right.......

Thanks Mitch, I seem to remember reading an article of similar tone some time ago but have evidently passed the information on to the birds. Too much information and unfortunately I cant upgrade my RAM. None the less good article, thaks for passing it on. It brings home that in fact I have been working a little in the wrong direction of late and it is good to get it sorted before I launch in to Angkor posed to take photos.

Thanks again, and thanks for the comment about the site. Getting there I guess.

Cheers

Ron

[ron chappel]

Ah ,it looks like you have the right idea anyway Ron (your big post about 4 up the page)
.. your well on the way to making the most of the sensor.Probably more so than most of us!