A2 histograms: live vs playback

This seems like a very good solution. Let me make sure I understand how you achieve it:

1. Set exposure mode to aperture priority.

2. Set up "spot toggle". (I'll have to figure out how)

3. Spot meter critical exposure area (in my case either the highlight details or skin tones), adjust exposure compensation as needed.

4. Lock exposure with AEL.

5. Recompose in viewfinder, half-press shutter release to lock focus. MY ASSUMPTION is that this will NOT unlock AEL.

6. Take the shot.

If this works, then it will be very close to my way of shooting transparencies.

Staxis said:

hpycmpr said:

Thanks for suggesting this alternative. I'll definitely try it out.
By "spot toggle", do you mean moving the spot metering point from
the center? BTW, how big is A2's spot metering area? How effective
is A2's spot metering in low light, i.e. at what EV can it support?

Click to expand...

Not quite. The AutoExposureLock button has four possible settings.
I have mine set on Spot Toggle (via a menu). This means that when
I press the AEL button it will take a spot reading and lock the
exposure to that value until I press AEL again. This gives you an
instant sopt meter reading whenever you want it.

Staxis said:

So far I have yet to play with moving either the focus point or the
spot metering point. One reason is that on A2, theses two points
seem to be tied together. In many situations, one would like to
focus on one point, but meter at a different one. Hope I can do
that on the A2.

Click to expand...

They are tied together but there is no reason why you can't do
this. I could do it with my Minolta film SLRs even though they
only had one focus point in the middle of the frame and the spot
meter always read from the centre of the frame as well.
--
Greg

When you've got a moment, have a look at my newly updated site:
http://www.wrightphotos.co.uk
also http://www.wrightphotos.co.uk/FromeInFocus

Winner of the South West Rural section of the BBC's Picture of
Britain Competition.

Click to expand...

Thanks for the clarification. I'll try some testing myself.

When I started out shooting transparencies, I did bracket frequently. After I became more confident with my exposure, I now only bracket when the subject in an image is stationary and the lighting is very challenging.

Bracketing digitally is only cheaper in $, but can be very expensive if the next shot is missed while the camera is tied up bracketing the current one. (And we all know that the one we missed is always the best!) But I'll definitely bracket more digitally when the situations permit.

Staxis said:

hpycmpr said:

Is A2's live histogram based on only the green channel officially
documented somewhere? Or is it objectively proven to be the fact?

Click to expand...

I recall seeing it documented somewhere but I could not give you a
reference. It is fairly easy to check by using a mixture of red,
blue and green targets.

Staxis said:

In either case, that will explain why there is such a big
difference between the live and playback histograms. But only if
the playback histogram is rgb composite.

Click to expand...

Staxis said:

Is histogram based on a single channel a common practice in the
lower end digicams? If I recall correctly, some DSLRs not only have
rgb composite histograms, but also include all three rgb individual
channel based histograms. That will satisfy those who absolutely do
not want clippings in any channels.

Click to expand...

Some DSLRs do indeed have histograms for each channel. Equally,
some don't.

I use the 'expose right' method a lot. To nail it with the A2 - or
my Sony A100 - I will establish a base exposure and then bracket,
just like with slide film. Bracketing using digital equipment is a
lot cheaper than with transparency stock. You could also ensure
that you have a little space at the right hand end ofthe histogram
to allow for errors - then it would be 'expose nearly right'.

--
Greg

When you've got a moment, have a look at my newly updated site:
http://www.wrightphotos.co.uk
also http://www.wrightphotos.co.uk/FromeInFocus

Winner of the South West Rural section of the BBC's Picture of
Britain Competition.

Click to expand...

It's very common for the luminosity histogram to track the Green channel in digicams. You can confirm this by looking at the captured image's histograms in your image browser or Photoshop or FastStone or Irfanview or any program that shows you the individual color channel histograms.
I think only the top end DSLR models display all the color histograms in camera.

I use exposing to the right but I place the highlight pixel data about 10% short of the right edge. This is usually enough to prevent the Red and Blue channels from blowing out highlights.
****

No. Not talking about the histogram now. I'm reffering to Jerre's solution to use the EVF live image as an indication for correct exposure. I'm saying that the image in the EVF looks somewhat different in live view and when reviewing it immediately after capturing.
Therefore I think Jerre's is a valid solution, but it's not precise.

--
Gideon



PAW - Week 31

hpycmpr said:

This seems like a very good solution. Let me make sure I understand
how you achieve it:

1. Set exposure mode to aperture priority.

2. Set up "spot toggle". (I'll have to figure out how)

3. Spot meter critical exposure area (in my case either the
highlight details or skin tones), adjust exposure compensation as
needed.

4. Lock exposure with AEL.

5. Recompose in viewfinder, half-press shutter release to lock
focus. MY ASSUMPTION is that this will NOT unlock AEL.

6. Take the shot.

If this works, then it will be very close to my way of shooting
transparencies.

Click to expand...

Your method looks almost the way that I would do it. Here's my version:

1. Set the AEL button to 'Spot toggle' Once this is done you don't ever have to repeat this step.

2. Select aperture priority.

3. Adjust exposure compensation to suit.

4. Take you spot meter reading from the target by pressing the AEL button.

5. Recompose in viewfinder, half-press shutter release to lock focus. The exposure will not change as it is already locked.

6. Take the shot.

7. Press AEL once more to unlock the exposure.

--
Greg

When you've got a moment, have a look at my newly updated site:
http://www.wrightphotos.co.uk
also http://www.wrightphotos.co.uk/FromeInFocus

Winner of the South West Rural section of the BBC's Picture of Britain Competition.

@ hpycmpr:

There is ,imho, not a real solution,at least; not in the camera.

Since i have dusted of my good old autometerIIIF the results have become more consistent.

Especialy when the light does not change for an hour or so, taking a incident reading at 90 degrees away from the sun and 45 degrees up to the sky seems to do the trick most of the times in combination with some under exposure(1/3 - 2/3 EV) on subjects with importent highlights or overexposure if something is hapening in the shadows.
Taking graycard readings with the spot/viewer attachment give the same results.

But unfortunatly this is not always a working solution, especialy when photographing people you tend to loose the shot because you are fumbling with technoligy in stead of concentrating on the right moment.

I think i have enough camera and fotographic experience to tell when and if a camera is unreliable in certain situations and i believe that is the unfortunate case with the A2 if you use it in situations which cannot be done again like taking pictures of people.

Just like "center weighted" meisurement in combination with low ISO slide film is deadly if you are on holiday in greece at 12:00, it has to be spot+M to get it right.

And , to my experiance, shooting with an A2 is like shooting velvia in high sunlight since it does not have the latitude in sensitometric values like ie fuji NPH400.(THE wedding film pur sang)

And if the camera does not offer any alternative then sorry but i will take a different device.

So my darkroom equipment and enlarger is back in use again and a few 12 packs of film lie in the fridge.

The only thing which i stil want to explore is the use of the contrast setting and how its effect turns out on prints.

The A2 is a great camera and it is very frustrating that is is capable of delivering such marvellous results but not at the moment you want it to do so.

The explaination,for me, is quite simpel; film and its gear has gone through over 100 years of development to reach a level of almost 100% perfection.
Digicams stil have a long way to go.

Robber-

You seem to be saying that the A2 can mess-up on the lighting readings unexpectedly, and perhaps for various reasons. Question: If that's the case, and you're shooting in RAW, wouldn't you be able to adjust the photo to a near-perfect shot? Or is this just not possible with the situation you are refering to? - You obviously seem to have tons of experience in this field. I'd appreciate your take on this.

John B.
A1

I have been trying out this method and find it to be much better than relying upon the live histogram. The following finer details are for my own record keeping and for others.

Staxis said:

hpycmpr said:

This seems like a very good solution. Let me make sure I understand
how you achieve it:

1. Set exposure mode to aperture priority.

2. Set up "spot toggle". (I'll have to figure out how)

3. Spot meter critical exposure area (in my case either the
highlight details or skin tones), adjust exposure compensation as
needed.

4. Lock exposure with AEL.

5. Recompose in viewfinder, half-press shutter release to lock
focus. MY ASSUMPTION is that this will NOT unlock AEL.

6. Take the shot.

If this works, then it will be very close to my way of shooting
transparencies.

Click to expand...

Your method looks almost the way that I would do it. Here's my
version:

1. Set the AEL button to 'Spot toggle' Once this is done you don't
ever have to repeat this step.

Click to expand...

Here's how I set up "Spot toggle", including the menual's page numbers:

P.107 Recording Menu, Tab 4, Spot AE area set to Center spot.
P.81 Recording Menu, Tab 1, AEL button set to AE toggle.

In addition, I set up the rear dial to adjust exposure compensation:

P.144 Setup Menu, Tab 4, Ctrl dial set set to third entry (i.e. in A mode, front dial adjusts aperture and rear dial adjusts exposure compensation)

Staxis said:

2. Select aperture priority.

3. Adjust exposure compensation to suit.

Click to expand...

With my above setup, I don't have to press the exposure compensation button. Simply operating the rear button will adjust the exposure compensation.

Staxis said:

4. Take you spot meter reading from the target by pressing the AEL
button.

Click to expand...

More accurately, first half-press the shutter release to take rhe spot reading. Then press the AEL button to lock the reading.

Staxis said:

5. Recompose in viewfinder, half-press shutter release to lock
focus. The exposure will not change as it is already locked.

6. Take the shot.

7. Press AEL once more to unlock the exposure.

Click to expand...

First half-press the shutter-release, then press the AEL button to unlock the meter reading. If the shutter-release is not half-pressed first, pressing the AEL button won't unlock the meter reading.

8. Reset the exposure compensation (with the rear dial in my setup).

Thank you for suggesting this method. Without it, it would have taken me lots of experiments to figure this out.

robber576 said:

@ hpycmpr:

There is ,imho, not a real solution,at least; not in the camera.
Since i have dusted of my good old autometerIIIF the results have
become more consistent.
Especialy when the light does not change for an hour or so, taking
a incident reading at 90 degrees away from the sun and 45 degrees
up to the sky seems to do the trick most of the times in
combination with some under exposure(1/3 - 2/3 EV) on subjects with
importent highlights or overexposure if something is hapening in
the shadows.
Taking graycard readings with the spot/viewer attachment give the
same results.

But unfortunatly this is not always a working solution, especialy
when photographing people you tend to loose the shot because you
are fumbling with technoligy in stead of concentrating on the right
moment.
I think i have enough camera and fotographic experience to tell
when and if a camera is unreliable in certain situations and i
believe that is the unfortunate case with the A2 if you use it in
situations which cannot be done again like taking pictures of
people.
Just like "center weighted" meisurement in combination with low ISO
slide film is deadly if you are on holiday in greece at 12:00, it
has to be spot+M to get it right.

Click to expand...

Agreed with all the above. When shooting transparencies, spot metering in manual mode is the only way I know to get the exposure right every time. In situations like Greece at noon, I would shoot in the shade, or put my camera away.

robber576 said:

And , to my experiance, shooting with an A2 is like shooting velvia
in high sunlight since it does not have the latitude in
sensitometric values like ie fuji NPH400.(THE wedding film pur sang)

Click to expand...

I have yet to experiment with raw converting the A2 images to be able to compare their latitude against Velvia's. With a film camera, an user has many film type choices. With a digital camera, an user is committed to a single film type.

robber576 said:

And if the camera does not offer any alternative then sorry but i
will take a different device.
So my darkroom equipment and enlarger is back in use again and a
few 12 packs of film lie in the fridge.

The only thing which i stil want to explore is the use of the
contrast setting and how its effect turns out on prints.

Click to expand...

Up to this point, I'm still figuring out A2's features and settings, and have yet to scrutinize the images in Photoshop or on prints. BTW, are your comments about the A2 images based on out of the camera, or with some amount of post-processing like raw conversions, etc.?

robber576 said:

The A2 is a great camera and it is very frustrating that is is
capable of delivering such marvellous results but not at the moment
you want it to do so.

Click to expand...

After playing with the A2 for only a few days, I have yet to come to a conclusion. But I definitely like its looks and how the features are laid out. Now when I pick up other cameras in the same class, I can't stand all the chrome switches, etc.

robber576 said:

The explaination,for me, is quite simpel; film and its gear has
gone through over 100 years of development to reach a level of
almost 100% perfection.
Digicams stil have a long way to go.

Click to expand...

Again in complete agreement. My take is that digicams' sw/firmware needs far more development and attention than hw. One good example is how A2's r1.14 firmware can make such a dramatic difference with the same piece of hw.

John_B said:

Robber-

You seem to be saying that the A2 can mess-up on the lighting
readings unexpectedly, and perhaps for various reasons. Question:

Click to expand...

I don't think that Robber is making that claim. The discussion is more about how to meter accurately with the A2.

John_B said:

If that's the case, and you're shooting in RAW, wouldn't you be
able to adjust the photo to a near-perfect shot? Or is this just
not possible with the situation you are refering to? - You
obviously seem to have tons of experience in this field. I'd
appreciate your take on this.

Click to expand...

With digital imaging, post-processing with Photoshop or raw conversion can rescue many but not all poorly exposed shots. Poorly exposed shots come in two broad categories. If the shadows or highlights are clipped, no amount of post-processing can bring back the details that are not captured to begin with. If shadows or highlights are not clipped, post-processing can bring out the details, but may be at the expense of reduced contrast and/or increased noise/artifacts.

For the best final image, nothing beats an accurate exposure at the beginning of the whole workflow, either on film or in digital.

hpycmpr said:

For the best final image, nothing beats an accurate exposure at the
beginning of the whole workflow, either on film or in digital.

Click to expand...

Spot on! The fundamentals have not changed at all.

--
Greg

When you've got a moment, have a look at my newly updated site:
http://www.wrightphotos.co.uk
also http://www.wrightphotos.co.uk/FromeInFocus

Winner of the South West Rural section of the BBC's Picture of Britain Competition.

hpycmpr said:

Staxis said:

hpycmpr said:

This seems like a very good solution. Let me make sure I understand
how you achieve it:

1. Set exposure mode to aperture priority.

2. Set up "spot toggle". (I'll have to figure out how)

3. Spot meter critical exposure area (in my case either the
highlight details or skin tones), adjust exposure compensation as
needed.

4. Lock exposure with AEL.

5. Recompose in viewfinder, half-press shutter release to lock
focus. MY ASSUMPTION is that this will NOT unlock AEL.

6. Take the shot.

If this works, then it will be very close to my way of shooting
transparencies.

Click to expand...

Your method looks almost the way that I would do it. Here's my
version:

1. Set the AEL button to 'Spot toggle' Once this is done you don't
ever have to repeat this step.

Click to expand...

Here's how I set up "Spot toggle", including the menual's page
numbers:

P.107 Recording Menu, Tab 4, Spot AE area set to Center spot.
P.81 Recording Menu, Tab 1, AEL button set to AE toggle.

In addition, I set up the rear dial to adjust exposure compensation:

P.144 Setup Menu, Tab 4, Ctrl dial set set to third entry (i.e. in
A mode, front dial adjusts aperture and rear dial adjusts exposure
compensation)

hpycmpr said:

2. Select aperture priority.

3. Adjust exposure compensation to suit.

Click to expand...

With my above setup, I don't have to press the exposure
compensation button. Simply operating the rear button will adjust
the exposure compensation.

hpycmpr said:

4. Take you spot meter reading from the target by pressing the AEL
button.

Click to expand...

More accurately, first half-press the shutter release to take rhe
spot reading. Then press the AEL button to lock the reading.

hpycmpr said:

5. Recompose in viewfinder, half-press shutter release to lock
focus. The exposure will not change as it is already locked.

6. Take the shot.

7. Press AEL once more to unlock the exposure.

Click to expand...

First half-press the shutter-release, then press the AEL button to
unlock the meter reading. If the shutter-release is not
half-pressed first, pressing the AEL button won't unlock the meter
reading.

8. Reset the exposure compensation (with the rear dial in my setup).

Thank you for suggesting this method. Without it, it would have
taken me lots of experiments to figure this out.

Click to expand...

You have given a very detailed description that others should find helpful. I'm pleased that my suggestions proved useful.

--
Greg

When you've got a moment, have a look at my newly updated site:
http://www.wrightphotos.co.uk
also http://www.wrightphotos.co.uk/FromeInFocus

Winner of the South West Rural section of the BBC's Picture of Britain Competition.

Just to clarify: i am not claiming to have found a solution,as i said before; i dont think there is a solution, at least not in the camera, my comments are just my 2 cents on the problem of getting correct exposure with a A2 and why a lot of us are strugling with it.

And understanding the problem may get you closer at finding a solution, if there is any at all.

The holy grail of "raw" shooting is just giving me more work with still the same outcome: a badly exposed shot is badly exposed and there is nothing which can change this no matter how many postprocessing you through at it.

You can not make what is not there in the first place whether it is in resolution,colour or brightness

At best the loss is 'acceptable" and can be masked in postprocessing to a level where it is not obvious any more and may give you a satisfying result afterall, but it still badly exposed and the frustrating part: although no one else may see it, you know it.
So nothing has changed there since the film era.....

Which brings me to the general feeling i have with the A2: i dont mind the noise, i dont mind the bad jpeg quality, i dont mind the lack in colour quality of the jpeg's, but i do mind the unpredictable exposure.

The general quality of the camera in jpeg mode is more then sufficient for me and i seldomly feel the need to trade in the speed of shooting jpeg for some more quality which comes with raw mode.

To my experience the loss in quality of bad exposure is far greater then any in camera bad jpeg conversion can cause.

So i would happily trade the raw possibiliity in for a real exposure metering system which gives me accurate and reliable results like i had on any of my film minoltas, but ofcourse this is not possible.......

And btw: the method above is what i generaly use if i dont want to bother with manualy exposure readings with a autometer, just forget about the histogram, use the spot meter and give some manual exp correction.

I always advise those new to photography to learn the two basics in using any camera: how to expose correctly, and how to focus and control DOF. When handling a new camera like the A2, I follow my own advice.

While there is no solution to equate getting a precise exposure with manual spot metering in a film camera, the suggested method for A2 discussed here is what I'll experiment with as a starting point of the whole workflow. The final evaluation is to see how the prints turn out.That'll take some time to get the hang of correlating what I see in the EVF with what the raw file looks like, followed by to learn what raw conversion can get me. Luckily, I'm quite comfortable with the tail end of the workflow, having edited in Photoshop and printing from my transparency scans for a few years.

My next A2 quest is to learn its focusing "features".

Thanks to all those who generously shared their inputs.

robber576 said:

And btw: the method above is what i generaly use if i dont want to
bother with manualy exposure readings with a autometer, just forget
about the histogram, use the spot meter and give some manual exp
correction.

Click to expand...

Couple of questions:

1) Am I correct that viewing the "final historgram", after the photo has been taken will give you a good indication of how well you did in exposign the photo using this "alternative metering" method? That is, the historgram will be accurate, as opposed to when you're first previewing the shot you're about to take.

2) You mentioned you like to meter a highlight and set exposure compensation to -2. Iis this a good rule of thumb to follow? How about if their aren't highlights, but skin is your main focal point. Is there a safe number to use their for exposure compensation?

I experimented at a Memorial Day Service yesterday using this new alternative method. I'tll take me a while to get used to, but it's easy enough to follow. Btw, it seems on my A1, the AEL unlocks by merely pushing the AEL button after taking the shot. I don't need to half-depress the shutter-release button.

Thanks guys for sharing this alternative metering method with us all.

John B.
A1

John_B said:

Couple of questions:

1) Am I correct that viewing the "final historgram", after the
photo has been taken will give you a good indication of how well
you did in exposign the photo using this "alternative metering"
method? That is, the historgram will be accurate, as opposed to
when you're first previewing the shot you're about to take.

Click to expand...

If the live histogram is based on single green channel, and the playback histogram is based on rgb composite, then the latter will definitely be more accurate. Having said that, there are a few additional curves:

1. WB settings can influence the histograms, see the current WB thread.
2. In-camera color space vs Photoshop's working space can make a difference.

But neither should be as dramatic as what I observe between A2's live and playback histograms. The histogram you will edit with is the one that is important. But I have yet to compare A2's playback histogram against ACR's. I hope that they are close. If not, back to the drawing board.

John_B said:

2) You mentioned you like to meter a highlight and set exposure
compensation to -2. Iis this a good rule of thumb to follow? How
about if their aren't highlights, but skin is your main focal
point. Is there a safe number to use their for exposure
compensation?

Click to expand...

When I spot meter in manual mode for transparencies, I can select a part in an image and get a desireable and precise exposure for it. (Come to think of it, that's how exposure should be controlled and set for any film/digital and for any subject/situation.) Often in contrasty images, that means sacrificing not-so-good exposures for other parts of the image. Here are three examples:

1. Highlight's details are important, such as bright white clouds or white bird feathers. I spot meter these areas, and set the exposure at +2, by adjusting either A or S. Since I'm in M mode, EC does not work on my film camera. (NOTE: in your post, you said -2. Not so!)

2. Shadow details are important, such as a black cat's fur. I do the oposite. Spot meter the fur, set the exposure by -2.

3. Skin tones are important, I do something similar to robber576's method:

http://forums.dpreview.com/forums/readflat.asp?forum=1024&message=21533104

"Example: i spot meter on a white(caucasian) person and know (by experiance) i have to apply a +1 1/3 stop correction to get correct skin tones."

For dark skin tones, I would make no or minimal exposure adjustment, depending on the tone range. For babies, well, you get the point...

BTW, to use the above skin tone metering method, avoid metering parts that are sunburnt, or with makeup, or in the shade, etc. That's why I use spot metering to precisely meter a tiny area.

John_B said:

I experimented at a Memorial Day Service yesterday using this new
alternative method. I'tll take me a while to get used to, but it's
easy enough to follow. Btw, it seems on my A1, the AEL unlocks
by merely pushing the AEL button after taking the shot. I don't
need to half-depress the shutter-release button.

Thanks guys for sharing this alternative metering method with us all.

John B.
A1

Click to expand...

It took me quite a while to get the hang of it with transparencies. But once nailed, it works great for me. Be patient and good luck.

hpycmpr-

Thanks for the reply. I've sure learned a lot recently thanks to your (& others') posts & inquiries. Seems like I was missing an important part of the puzzle. Now with a better understanding of exposure/metering, I hope to take even better photos.

I was wondering if you (or others) think there would be any merit in using the flexpoint cross bars instead of the larger "center spot circle" when metering? Seems you could fine point the metering with the flex point more precisely.

Also, a common point mentioned here over the years is that the Ax cameras overexpose routinely. Consequiently, some folks have suggested using exposure compensation of -.3 routinely. I'm thinking the "alternative method" you & others have shared here, that won't be necessary.

Thanks again for all the tips. As I said, I'm learning lots!

John B.
A1

John_B said:

I was wondering if you (or others) think there would be any merit
in using the flexpoint cross bars instead of the larger "center
spot circle" when metering? Seems you could fine point the
metering with the flex point more precisely.

Click to expand...

The flexpoint cross bars increase focussing accuracy but will not affect exposure accuracy. The 'flex point' can be moved across the frame but it seems that the spot metering area remains in the centre of the frame.
--
Greg

When you've got a moment, have a look at my newly updated site:
http://www.wrightphotos.co.uk
also http://www.wrightphotos.co.uk/FromeInFocus

Winner of the South West Rural section of the BBC's Picture of Britain Competition.

Staxis said:

The flexpoint cross bars increase focussing accuracy but will not
affect exposure accuracy. The 'flex point' can be moved across the
frame but it seems that the spot metering area remains in the
centre of the frame.

Click to expand...

Or NOT, as the case may be!! ;-)

The A2 actually offers a choice within the menus -- spot metering point can be made to follow the Flex Focus Point, or stay locked in the centre.
--
Regards,
Baz