Will histogram help?

[martycon]

I have had exposure problems. Tried bracketing, and discarded images based on what I saw on camera. Prints looked nothing like I thought they would. I am about to try using the cameras histogram facility, but what metering mode should I use. A quick visual trial suggested that all gave a similar histogram. Previously I have used spot metering on what I think is an appropriate part of the scene, and have had good results. Unfortunately this does not seem to work well with my new camera, Sony DSC-HX1. Any advice will be appreciated.

[arthurking83]

Always try to use the camera's histogram to get an idea of which images have been exposed as expected, or may look best for processing.
The look of the histogram is a personal preference thing, as is exposure itself but up to a point.
.... but the histogram never lies and should be relied upon for 'correct exposure'.


..... and discarded images based on what I saw on camera. Prints looked nothing like I thought they would. .....

This part seems to be a bit ambiguous(at least to me), but what I think you are implying here is that the prints don't look as expected compared to the images you see on the camera?
If this is correct, you shouldn't really rely on the camera review screen to determine how the image should look in print.
A PC is a better gauge for expected print quality, and a calibrated screen on that PC will (or should) provide an even better gauge of how the image should look in print.

Also!(very important!!!) are you referring to home made prints or prints from a printing service(of any type)?

if prints are home made, then the printer may also be a source of contention as the print driver, print paper type, inks used all have a large bearing on the final print.
if the prints are from a print service(consumer or professional) then they will have a pre set quality and method of printing.

(If the prints are from a print service) now that you have a set of prints(even tho you are not happy with), what you would now do is to adjust your screen to match the look of the print.
Once you have done that, you then take use another image, process it to look as you want it too and get that printed from the same print service.
The theory is that this next print shoudl more closely resemble what you expected it to look like(as per PC image)

If you printed the images yourself on your home inkjet, then you can do the same thing as above(which is a bit of a waste of ink), and it may work for this batch of paper with this same set of inks, but it may not if you change the paper type and ink set in the printer.

For an idea of how close your screen is set to a good calibration point, how does the greyscale bar at the bottom of the page look?
Can you see all the step wedges?
Are there any obvious colour casts to the grey wedges?
If so you may want to invest in a screen calibrator.

.. hope this helps a bit, but as the info is slightly vague, a more positive answer is hard to provide at the moment.

[William W]

I have had exposure problems. Tried bracketing, and discarded images based on what I saw on camera. Prints looked nothing like I thought they would. I am about to try using the cameras histogram facility, but what metering mode should I use. A quick visual trial suggested that all gave a similar histogram. Previously I have used spot metering on what I think is an appropriate part of the scene, and have had good results. Unfortunately this does not seem to work well with my new camera, Sony DSC-HX1. Any advice will be appreciated.


1. Apart from using a new camera, what other elements, specifically and in deatil, of the Shot to Print chain, have been changed?

2. What was your old camera; and do you still have it?

WW

[ricktas]

f your prints do not look like they do on your computer, it may not be a histogram issue, rather a monitor calibration issue. http://www.ausphotography.net.au/forum/forumdisplay.php?163-Colour-Management

[ameerat42]

So "Using Histograms"?
I do not, as a rule. This is because I only thought of them as a tool to show you your range of Luminance and Chrominance across the channels.

Does it mean that a histogram should be an even-ish looking bell curve?

(Having asked, I bet there's a tutorial/library on this:rolleyes:? Yes, here. (http://www.ausphotography.net.au/forum/showlibrary.php?title=Tutorials:RAW_:_Starting_to_process_RAW_files&highlight=histogram))
Am.

[mudman]

why were you using spot metering on a landscape?
if you meter for the whole scene you get a more representative measure of the light.
if you then look at the historgram you will get an accurate measure of where the dark and bright parts of thee scene.
you can then adjust the ev to even out the metering so that you get more mid tones and reduce any blown areas in the scene.
this can give a much more pleasing result

[arthurking83]

spot metering is better for landscapes if you aren't in a hurry and just want the shot and then move on.

many landscape scenes will have a higher dynamic range than the 'sensor' can capture in a single exposure, so you need to work out for yourself which parts of the scene you want captured and which parts are 'less important' for that particular scene.
So you use spot metering to pan around the scene, taking readings from various areas and adjust the exposure accordingly(whether using manual mode or any of the semi auto modes .. that's up to you)

what I do is set to spot metering, and if the scene is agreeable to having one of the focus points(51 on a D300 spread very widely across the vf) positioned over the area I want to concentrate on, I'll set the camera to [A] mode and possibly set in an amount of exposure compensation once I've determined my exposure value. I'll set exposure compensation if I now that I need to adjust heavily in PP later.
I might add a filter or two as well, but the point is that I also may sit there for a while waiting for the light to 'come back' too... in [A] mode.
If the scene is in shadow(cloud cover) at one point and I'm waiting for the sun to peek through a brief break in the clouds on that same point, then I want two things set on the camera.
1. [A]perture priority
2. spot metering.

Aperture priority because the light level changes so wildly and quickly that I can't react as quickly as the camera can for the exposure value I want for that particular spot.
Spot metering because that part of the scene is the important part, and other parts of the scene may require another exposure level which the camera will adjust for.


I have to say that one you understand what it is you want from the metering/exposure side of the equation and have the experience behind you to effect that exposure, spot metering is the best way to set your camera(depending on camera model too tho!)
The only time I don't use spot metering is if I'm using any flash. Nikon's flash system is generally better than I am at exposing itself correctly! :D

caveat: Nikon's cameras spot metering system works be metering that spot area at the same point as the focus area point through the viewfinder. I believe this system is both complimentary and efficient in the way the camera operates. Not all cameras operate this way, where the spot meter point is only in the centre of the frame.
If your point of interest is off this central spot metering point and the framing is set so that the subject is off centre, the camera is no longer metering off the point of interest.
This is the reason I use spot metering. On a camera that operates in this manner it's an effective way to shoot.

[martycon]

William, thanks for your interest. Old cam was olympus compact, better than point & shoot, but now gone. Printer is same but monitor is better and calibrated with AP charts. The nub of the matter is that I would like the print to look the same as I remember, as for lighting without having to adjust levels & brightness in photoshop. I think I need another tool apart from the cameras preview image. Review of images from olympus indicates that I have tended to over expose these, whereas I underexpose the new. I usually use spot metering on the zone of interest within the frame, and have done so for many years. Kind regards, and thanks again.

[martycon]

Thanks Am, I did make a brief search of AP for histograms but didnt look in raw. I am impressed and thankfull that you did. The tutorial is excellent. I will re-read it after using the histogram facility, which is now set as default in my viewfinder. There is a good possibility that you have solved most of my problem. My thanks again.

[martycon]

Thanks mudman, I will definitely use histogram in future, and as you say, adjusting EV may be better than using spot metering. Regards, marty.

[martycon]

Thanks Rick, I have calibrated monitor with aid of charts available on AP. The responses from members are excellent, thank you for the FORUM and AP.

[martycon]

Thank you Arthur, for your comprehensive information. In retrospect, my problem is that i want prints and monitor to look like my memory of the lighting of the scene when the exposure was made, without needing to constantly adjust with levels in photoshop. You confirm that I should be using both spot metering and histogram. I have checked monitor calibration. and adjusted brightness to match that of 10x8 prints, and look forward to becoming competent in the use of a histogram, and the achievement of my goal, with thanks to you and others. kind regards, marty.