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New A900

H

hardloaf

Guest
Typing some of these long posts on a 3" touchscreen keyboard deserves its own thread about technique! :LOL:
Interesting! Please do explain the technique :clap:
The A900 is much more conservative in metering than its counterparts, and that has given the camera a bit more of a bad rap than it deserves in regards to noise, IMO.
BTW - I did check that Zone option. I'm pretty positive now that it changes only light meter bias with 0.5EV steps. So -1 takes half stop off from highlights. This means if somebody finds that A900 underexposes too often Zone -1 should take care of that. 1 and 2 will give 0.5 and 1.0 more to highlights. There is no difference if your exposure step is set to 0.3 or 0.5, but 0.3 can be confusing because it doesn't fit exactly in 0.5 zone step, so meter may show 0.6 or 0.3 difference if you check it with different Zone values. Not an issue.

This is especially critical if you're using ACR/LR, because, as has been said many times, the design of that converter seems particularly bad at dealing with the A900 files, partially because of the camera's great color separation. Sony didn't help things by designing a camera with an ideal ISO of 320. :wtf:
ISO numbers for Raw shooters are totally bogus in all kinds of cameras anyway. There is no standard here and vendors are getting more and more creative with every new model. Some camera models from different vendors have more than full stop of difference for the very same ISO number.

I also want to chime about UniWB a little. It definitely has it's disadvantages and this is entirely camera vendors fault that they still cannot implement proper histogram and clipping warnings for Raw after all those years. Yes, it's green and ugly. My daughter thinks that daddy is joking when sees her green portrait on LCD and laughs, my wife gives me those cuckoo looks and I have difficulties with understanding if shot is sharp enough. However it works and there is no other options unfortunately to get real control over exposure. Last example - I was shooting with flash in a room with warm colored walls and floor. Camera was set to AWB and did balance ok, so pictures on LCD looked decent except one problem - it was constantly showing clipping warnings in some unexpected areas. So I started dialing it down more and more till they stopped blinking, but now picture was definitely underexposed. Here it actually occurred to me that I have AWB. So I switch to UniWB, restore initial settings and guess what - no damn blinking. So there was no overexposure in first place, that's just AWB while compensating flash and colored reflected light clipped some channels and showed the warning even though in Raw data there was no clipping.

I'll let everyone to make their own conclusions :)
 

jonoslack

Active member
My posts are geared towards getting the highest quality RAW data at capture, because I deal with looks and style after the fact, but I surely understand that we all go through our photography journeys in a different way. :) Party!!
HI Douglas
You know I wasn't criticising your approach when you talked about uniWB - I've found all your posts extremely valuable, and these days I'm mostly shooting at 320 ISO - the other settings are different as I'm using Aperture and it seems to treat the RAW files more straighforwardly.

There is so much information to learn here.

Personally, I like to keep settings on the camera the same as much as possible, (hence the daylight WB), because my small brain doesn't do well with things changing around. I get better when I can predict and understand what's going on, and for me, that means simple!:banghead:

Anyway, this post was just to reaffirm that I was in no way criticising your valuable input.
 

jonoslack

Active member
Hi Terry
I love the guy with the suit and the basket. As for the colours - well, perhaps it's just me, but they simply look 'right' to me. Whatever - I hope you're happy!

Andrey - Thanks for chipping in, I'm a bit slow on the uptake, and I've just realised who you are - great to have you around here.

Interesting points, both about uniWB and about the underexposure. I only use AWB in mixed lighting indoors, and noise isn't usually too much of a problem, but this knowledge is a powerful thing!

Most of my shooting is outside, and the camera is simply left on daylight WB, I don't often look at the histogram, as I can 'feel' the exposure from looking at the LCD, but I realise that I've long since stopped worrying about blown highlights. There are lots of ways of 'knowing' your exposure, consistent settings and experience can sometimes get you there without too much understanding . . . but it's so good to have these things explained!
 

douglasf13

New member
Interesting! Please do explain the technique :clap:


BTW - I did check that Zone option. I'm pretty positive now that it changes only light meter bias with 0.5EV steps. So -1 takes half stop off from highlights. This means if somebody finds that A900 underexposes too often Zone -1 should take care of that. 1 and 2 will give 0.5 and 1.0 more to highlights. There is no difference if your exposure step is set to 0.3 or 0.5, but 0.3 can be confusing because it doesn't fit exactly in 0.5 zone step, so meter may show 0.6 or 0.3 difference if you check it with different Zone values. Not an issue.



ISO numbers for Raw shooters are totally bogus in all kinds of cameras anyway. There is no standard here and vendors are getting more and more creative with every new model. Some camera models from different vendors have more than full stop of difference for the very same ISO number.

I also want to chime about UniWB a little. It definitely has it's disadvantages and this is entirely camera vendors fault that they still cannot implement proper histogram and clipping warnings for Raw after all those years. Yes, it's green and ugly. My daughter thinks that daddy is joking when sees her green portrait on LCD and laughs, my wife gives me those cuckoo looks and I have difficulties with understanding if shot is sharp enough. However it works and there is no other options unfortunately to get real control over exposure. Last example - I was shooting with flash in a room with warm colored walls and floor. Camera was set to AWB and did balance ok, so pictures on LCD looked decent except one problem - it was constantly showing clipping warnings in some unexpected areas. So I started dialing it down more and more till they stopped blinking, but now picture was definitely underexposed. Here it actually occurred to me that I have AWB. So I switch to UniWB, restore initial settings and guess what - no damn blinking. So there was no overexposure in first place, that's just AWB while compensating flash and colored reflected light clipped some channels and showed the warning even though in Raw data there was no clipping.

I'll let everyone to make their own conclusions :)
Ha, I was just teasing about the iphone technique, Andrey. I'm not particularly fast at it, and I apologize to everyone for the typos that result from using that phone! :LOL:

As far as ZONE, thanks for clearing that up. The .3 step thing was misleading me a bit. I think I'll keep mine at -1 ZONE setting.

Oh, Jono, I didn't feel criticized by you at all. No biggie :) The pleasant nature of this forum is my favorite thing about it. I can't remember for sure, but I think I started using daylight WB consistently after reading one of your threads in the past. You're the man!

Terry, that camera sure does rendering things nicely, huh? That, combined with your eye, is gonna be one lethal combo. :clap:
 

ptomsu

Workshop Member
Terry,

very appealing shots! I start liking this camera and the 135 from what I see - which is bad because I should spend my money in a MF system :LOL:
 

Jonathon Delacour

Subscriber Member
Just to be contrary. Although I completely subscribe to most of Douglas theories, I've found that setting a white balance (daylight in my case) and then sticking to it rigidly means that you really get to understand the colour balance of the camera, added to which you aren't trying to standardise the colour in natural environments when you're really trying to capture the nature of the light rather than a mid grey.
Of course, if you're taking shots indoors of paintings it's a different matter, but outdoors I think it's a good principle.
It also means that if you do want to change it in post processing you can easily make a batch change to all your images . . . but I find it does a grand job anyway.

It's a bit like deciding to settle for a particular film stock and then sticking to it, it becomes part of you, rather then dithering about from one setting to another.
Exactly the same here. I shoot 99% daylight, and mostly at ISO 100. I'm sure Douglas has a point, but I like to keep my life simple, and trust the camera manufacturer with the settings. I am getting excellent results with my A900 and IDC so I don't feel any need to change what I'm doing. Like Jono, I consider WB and the different creative styles as different kinds of film. I think the A900 produces excellent color without any external help.
With the caveat that I'm a relative newcomer to using UniWB, I'd also like to chime in on the UniWB issue since Jono's and Edward's comments suggest that they are perceiving the issue in terms of color and white balance whereas UniWB is primarily about exposure and dynamic range (although these factors can obviously be impacted by one's choice of white balance).

As I understand it, the main problem is that -- even if you shoot RAW -- the luminance and RGB histograms displayed on the LCD screen are based not on the actual RAW data but rather on the in-camera JPEG which has been created by applying your white balance, saturation, sharpness, contrast, white balance, etc settings to the RAW data. Moreover, because a Bayer array has two green sensels for each red and blue sensel, a gain factor (whose value depends partly on the selected white balance) is applied to both the red and blue channels to "equalize" the channels. This means that the histograms will be inaccurate for any images that contain significant areas of bright red or blue because those values will have been "amped up" in the JPEG to the point where it appears they are being clipped whereas, in reality, they could get more exposure without any danger of blown highlights.

Since digital sensors capture linear data, half of the 4096 levels in a 12-bit capture are devoted to the brightest stop. Underexposing -- which is what the in-camera histograms frequently encourage us to do -- leads to throwing away a lot of the information that the sensor is actually capable of recording. This post to a UniWB thread at DPreview contains a lucid explanation as to why you might want to use UniWB:
...uniWB gives you a histogram that more accurately portrays the end points of the RAW data, allowing you to more accurately see when your image could take more exposure or when you've blown highlights. So, if you aren't having exposure issues today, why would you want to consider using uniWB? Besides being able to conclusively see if any color channel is really blown or not, what uniWB really allows you to do is to achieve the maximum exposure possible by increasing exposure until the histogram is maximally to the right without blowing any highlights. So, why would you want to do that. The answer is that this "expose-to-the-right" (ETTR for short) technique allows you to get the maximum dynamic range out of your sensor and your image and the lowest noise in the shadows. Anytime you don't use the full highlight range of the sensor, you are not taking advantage of the full range of the sensor and you then can't record as much dynamic range as if you had used the full range. So if you have a sunny shot with bright highlights and dark shadows, uniWB allows you to set the exposure for the most dynamic range possible without risk of blowing highlights. An inaccurate JPEG-derived histogram does not give you as accurate information and thus you might either not expose as much as you could or you might accidentally overexpose and blow some highlights.
However if you're shooting landscapes in relatively even light, where large areas of the image are already bright green and there aren't extremes of contrast, then UniWB is not as useful because the JPEG green channel histogram is providing you with all the information you need to make an accurate exposure.

To set up UniWB on a Nikon camera, the gain of each color channel is set to a factor of 1 by creating a custom white balance based on a specially created image, all of the in-camera settings that are used to produce the in-camera JPEG are zeroed out, and a linear Tone Compensation curve is selected. Douglas's settings for the A900 would appear to emulate this procedure.
 
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jonoslack

Active member
With the caveat that I'm a relative newcomer to using UniWB, I'd also like to chime in on the UniWB issue since Jono's and Edward's comments suggest that they are perceiving the issue in terms of color and white balance whereas UniWB is primarily about exposure and dynamic range (although these factors can obviously be impacted by one's choice of white balance).
Thank you Jonathon - what an excellent clarification - and so nicely written and put together
Thank You
 

douglasf13

New member
Aye, Jonathon, you are much better at explaining this stuff than I am. Thanks. In any event, I still get all of the advantages that Jono mentions with his WB method, even when using uniWB, because I have the A900's daylight WB value saved as a preset in my RAW converters, so one quick batch click on import changes my green images into A900 daylight balanced images. The only disadvantage is that the image is green on the camera lcd, but I'm getting used to that.
 

Terry

New member
Spot Metering using AEL

OK, now I'm trying to learn some stuff on the camera. :p

Right now I have the camera on matrix metering and the single point focus.

Now let's assume I want to spot meter and then focus. I understand that I pick the spot that I want to get a reading/lock exposure for. I press and hold the AEL button. Then I go and recompose and half press the shutter for focus.

Once I press the AEL button and then move the camera to recompose and focus, I do see the mark on the exposure compensation scale (in the viewfinder) move around. What I don't understand is how you would then actually change the exposure comp with your finger already holding AEL button. Or, is the camera doing something (implementing and EV change) on its own?
 

Eoin

Member
Hi Terry, you know what they say "Read the Manual"

Press the menu button, go to the cog wheel menu page 2, highlight AEL button, select spot metering AEL TOGGLE and your good to go.You just press the button once to go to spot metering and hold the value measured. No need to hold the button. Then you can press the exp comp button on the top behind the shutter release and dial in the comp required.

When you want to go back to normal metering just press AEL button again and the star will disappear in the VF.......... don't forget to cancel the exp comp you had dialed in
 

Terry

New member
Thanks Eoin,

I did have the manual but was a little :confused: between the menu choices and the the manual (pages 71-72 in US) saying you needed to hold the AEL button.

Terry
 

Eoin

Member
Sorry I forgot, in the method you're currently using, once you press the AEL button and hold it you are taking a spot reading (assuming you have it set to Spot metering AEL Hold. as you keep you finger on the button and recompose and focus the indicator moving around is showing you the current value of the spot metering point relative to your held metering value.

You can also set the exposure compensation to be always available on the front or rear dial rather than have to press the exp comp button. This can be set in the cog wheel menu page 2 "Dial Exp Comp fornt or rear wheel.

I'd also suggest if your going to use this setting you also set Control dial lock to on. What that does is lock the 2 control dials, until you actually meter or half press the shutter. I found without this setting on the camera rubbed against my side adjusting the exp comp I had set.

Hope that helps..
 

Braeside

New member
I've found all your posts extremely valuable, and these days I'm mostly shooting at 320 ISO - the other settings are different as I'm using Aperture and it seems to treat the RAW files more straighforwardly.

There is so much information to learn here.
.
Jono, as you know I'm using Aperture here as well, and recently, as a result of Douglas's posts on ETTR and making adjustments to Lightroom to compensate, I revisited some of my RAW photos in Aperture to see what the RAW histograms looked like when I had shot trusting the camera matrix metering.

They didn't look underexposed on Aperture's histogram, but then I remembered about the RAW fine tuning and Boost that is used by default in Aperture, this is set to 1.0 and has the effect of turning up the exposure quite a bit, fooling me into thinking that the capture was 'properly' exposed.

Even so, in Aperture I have found that I now prefer turning 'boost' down to about 0.5 and manually playing with exposure and contrast in Aperture to get the results I want. I have made a new RAW fine tuning preset for importing my files now with boost reduced.

Interested if you have noticed the same kind of thing?

Terry, sorry to have hijacked this - I'm impressed with your photos on the first outing, the market looks like a great place to photograph.
 

Eoin

Member
I'm using aperture as well (no surprise there!) and I'm finding ISO 320, matrix mode metering and AWB works very well.

I'm going to spend the day playing with Douglas's settings and see what the results look like. Who knows, I might even go as far as full manual mode, UniWB and use the histogram for one in my life :ROTFL:
 

Terry

New member
Thanks again Eoin!

Braeside - Hijack away all this info is a great referenence for someone starting out with this camera. The farmers market at the ferry building in SF is fantastic and not just for photos. There are sooooo many farms close to SF we have a great supply/variety of local veggies, meats, cheeses, nuts....
 

Diane B

New member
I agree with Jono. The colors (on my calibrated monitor) just look 'right'. I paid special notice to reds/burgundies and greens. BTW--I've always envied the markets in Calif.--all those wonderful veggies and cheeses.

Looks like you're having good fun with the camera and have more or less made up your mind as to which one you're going to take to Iceland *smile*.

Diane
 

Terry

New member
I agree with Jono. The colors (on my calibrated monitor) just look 'right'. I paid special notice to reds/burgundies and greens. BTW--I've always envied the markets in Calif.--all those wonderful veggies and cheeses.

Looks like you're having good fun with the camera and have more or less made up your mind as to which one you're going to take to Iceland *smile*.

Diane
Hi Diane,
I agree, that is why I posted so many yesterday (that had some screwy focus but did highlight the colors). When the files opened up in LR I didn't feel like I needed to touch them at all. The camera fits my hand pretty well. I still have work to do on the buttons to push (as you can see from my last couple of posts :p) but it is simpler than my Nikon in operation. Today I am going to work with the 24-70. We have hit a foggy patch in SF and it never cleared by the coast or the city yesterday. I may need to head inland....

The Ferry Market in SF is great. SF is a good town for dining out and cooking in. I try and go every Saturday that I am in town.

Back to photography...I will post a couple from the afternoon. It is amazing to put these at 100% on the monitor. I will post a couple of crops as well. I am sure the 1DsMKIII and the D3x make gorgeous files at 100% just catches you by surprise moving from 12 to 24 mp. I can easily send (actually load on line) you or others a RAW file(s) to play with. Jono also has a link.
 
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