D-Range - to use or not to use?

Hi all -

Whilst reading (and drooling over) the recent K7 reviews, I noticed that the D-Range functionality has been carried over. Now, I've tried it on my K200D but I can't quite make my mind up whether it's better to leave D-Range turned on and shoot at ISO 200 (the lowest offering available) or turn it off and shoot at ISO 100. Have any of you done any "scientific" testing of this function, or do you ignore this namby-pamby hand holding and go as manual as you can?

I did try it out once (see this thread) but didn't get round to do the 'scientific' test. So that one was only giving an indication.

I almost always leave D-range turned on.

Prieni

I'm just considering this function too having just bought a K20D, having done a little reading & posted a thread or two on here it seems that it can cause some shadow noise which I'm non too kenn on...I'm trying the camera initially with D Range turned off

simon

I use it when shooting macro as it helps pull details out of shadow. I don't use it when shooting birds as it introduces too much noise for me. I think it depends on the situation as to whether it's a good idea or not.

I switched that off on my K20D after a short time playing with when I noticed that all my pictures (even @ISO200) gained some noise in shadows.

Can someone explain in layman's terms what the D-setting is all about?

What I can glean is that it somehow boosts the brightness of the image, but am not sure why you would use it instead of simply adjusting the EV or changing some other setting. So what, in kindergarten terms (remember I am new to DSLR idosyncrasies) is the D-setting for and why would you opt to switch it on? I have seen that when you do switch it on the 100 ISO disappears so what is really going on? Obviously I have read the manual on this but am still really none the wiser

In 35mm film terms, think of it as automatically 'push processing' the dark areas while leaving the highlights as they are so they don't burn out.

You can do the same thing with more control in a RAW converter or even in PS.

As far as I understand this function, switching on Expanded Dynamic Range will increase the dynamic range of the image sensor at the cost of reduced ISO range (you loose the ISO 100 setting).

This means that the image sensor can detect more levels of light from bright to dark. Sounds good, but on the other hand you loose the low noise ISO 100 setting.

Personally, I have not given this function a thorough test. I tend to use manual ISO setting, and selecting ISO 100 for well lit scenes or flash to reduce the noise as much as possible.

Hopefully the above is correct, otherwise I am sure somebody will be quick to correct me.

Nice explanation Pentaxophile!
I do not concur, though with the assessment that you can do the same thing in a RAW converter or PS. Once the highlights are burned irrecoverably the RAW converter cannot do anything about it.
If you look at my examples in the other thread I referred to, you can see that even for a +2.5 EV shot I was able to recover almost all of the highlights. So it's doing a bit more.
But then, you tried to simplify...

Prieni

So it will boost the shadow areas and not blow the highlights, but at the risk of giving you more noise or grain in film terms?

So if you are someone who likes grain in your B&W like me (I know that probably makes me odd) then it should be enabled?

Prieni - you did not take any shots with D-Range disabled, so it's inconclusive whether you would have been able to retrieve the same amount in your Raw Converter! I have a hunch you would have done, as I have had sucess at retrieving blown highlights simply using Raw Shooter Essentials.

I think they key is to experiment... these things are down to user preference at the end of the day. It probably does increase noise a bit, but not heinously so... even so I personally would only use it if you know the shot is problematic.

I like grainy black and white too, but I don't like splodgy, coloured noise in my photos!

With photography, everything has both pros & cons...you never get a free lunch. You just need to decide which balance of the pros & cons suits your photography...

cheers Steve.M.

Well, to give the new Silkypix RC a test run and to answer the long standing question I tried to perform a test that is a little bit more exhaustive. I took a test frame with a high dynamic range:
[IMG]http://i156.photobucket.com/albums/t5/Prieni/_PRI6500all.jpg[/IMG]

I took a lot of shots from +0EV to +3EV (as shown in the viewfinder), manual settings of aperture (constant 11) and time. The poppy is out of focus as I wanted to concentrate on the fine structure of the background (as it is the background that blows out).

Here are 100 percent crops of the lower right corner. These were developed in SilkyPix Pro, pulled back -1.4 EV.

1. ISO 100, +2 EV
[IMG]http://i156.photobucket.com/albums/t5/Prieni/_PRI6492.jpg[/IMG]

2. ISO 200, +2 EV, D-range off
[IMG]http://i156.photobucket.com/albums/t5/Prieni/_PRI6497.jpg[/IMG]

3. ISO 200, +2 EV, D-range on
[IMG]http://i156.photobucket.com/albums/t5/Prieni/_PRI6500.jpg[/IMG]

To see the influence on the shadows I developed the images again, this time with +0.5 EV in SilkyPix. Crops are from the center of the frame:
1. ISO 100, +2 EV
[IMG]http://i156.photobucket.com/albums/t5/Prieni/_PRI6492_1.jpg[/IMG]

2. ISO 200, +2 EV, D-range off
[IMG]http://i156.photobucket.com/albums/t5/Prieni/_PRI6497_1.jpg[/IMG]

3. ISO 200, +2 EV, D-range on
[IMG]http://i156.photobucket.com/albums/t5/Prieni/_PRI6500_1.jpg[/IMG]

For me it shows that by leaving D-range on not much is lost. Yes, 200 ISO does show more noise than 100 ISO and perhaps the 200 ISO with D-range on is a smidgeon noisier than 200 ISO with D-range off, but it is hard to make out the difference.

Prieni

P.S.: No poppies were harmed during these tests, it's an artificial flower. The EXIF data have been saved with the JPG's for you to examine.

Thanks Prieni, I normally use 200 and D-range on as I normally do hand-held and assumed it would give me a little more latitude. Your window blinds with D-range on look better and I can't see any deficit in the poppy so I'll continue with it on. (I don't get a lot of time on the computer since the g/f discovered Flickr with her mobile phone:roll.