Auto vs Manual

Hey guys, newbie here, of course. Just bought a GX-85 for me and my wife to play with. Tonight we were in the back yard taking pictures in auto and they looked bright and really good. When we switched to manual mode with the same settings as auto used, the pictures are, for lack of a better word, dim.

Any ideas?

xman111 said:

Hey guys, newbie here, of course. Just bought a GX-85 for me and my wife to play with. Tonight we were in the back yard taking pictures in auto and they looked bright and really good. When we switched to manual mode with the same settings as auto used, the pictures are, for lack of a better word, dim.

Any ideas?

Click to expand...

Post the pictures. My guess is the same settings were not used.

Make sure ALL the same settings were used. For example, sometimes I do something similar, I will use an auto mode just to get a starting point for exposure and I'll switch over to Manual and use the same aperture and shutter speed I saw in Auto. But the picture looks too bright or dark.

And then I'll notice that what I did not do is check which ISO that the auto mode chose. When I take that and apply it in manual mode alongside the aperture and shutter speed, then the images match.

On some cameras there may be additional settings that affect exposure, like whether a built-in neutral density filter is applied or not.

this is the auto image, the iso is 500



this is manual but the ISO is 400 because there isn't a 500 iso setting on the camera.

would the 100 iso difference make that much difference? All the pictures on manual settings in great sunlight look great.

I posted this before reading the second comment, i will have a look at that now.

xman111 said:

this is the auto image, the iso is 500



this is manual but the ISO is 400 because there isn't a 500 iso setting on the camera.

would the 100 iso difference make that much difference? All the pictures on manual settings in great sunlight look great.

I posted this before reading the second comment, i will have a look at that now.

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These seem to have been taken several minutes apart, likely near dusk when scene lighting changes rapidly. Along with the exposure, there are differences in white balance--with the auto likely being taken when the ambient lighting was much warmer.

Here are the two side-by-side, with some white balance adjustments but no brightness adjustments:

ya they were 3 minutes apart. this was only one example, all the pictures seem to be like that. Do you have any suggestions? i will show my wife that pic.

xman111 said:

ya they were 3 minutes apart. this was only one example, all the pictures seem to be like that. Do you have any suggestions? i will show my wife that pic.

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You'd be surprised at how much lighting can change in 3 minutes around sunset.

Try again in controlled lighting, such as indoor lighting.

Also, control your exposure in manual rather than just using what Auto would give you...that's sort of the point. A longer shutter speed, lower f-number, more scene lighting will all give you more exposure. A higher ISO will additionally give you a brighter image.

Finally, look at all of the JPEG rendering settings if you plan to use the JPEGs from the camera.

after reading your post, we went and looked at the white balance setting on the camera. In manual mode, we were in the bright sunny skies setting by mistake. When we put the white balance to AWB (Auto), the pictures looked more like the proper color and the darkness seems to be gone. We are going to take some more pictures to try. I really hope that is what it was. Will report back!

White balance was my first guess when I looked at the pictures.

Often in Auto mode it is set to Auto and in manual mode you can set it - and if it's set to 'Sunny' the picture becomes colder.

There may also be things burried in the menus about highlights, shadows, 'vivid' colors and 'warm shadows' - all affect the image color. On Auto these may be preset and fixed, whilst in P-A-S mode they may have a different setting - which you can most likely change.

Read the fine manual.

It is a golden rule that if the shooting parameters would be the same, the exposure of the images should be the same (if no major change in shooting condition). Auto or M is out of the equation.

However, when looked at the EXIF of your 2 samples, the Auto one used Auto WB and the Manual one used Manual (Tungsten) WB... I supposed it explained the different color scheme of the 2 samples. In terms of exposure, that 100 different in ISO (1/3ev?) wouldn't give much in exposure difference.

Had you erroneously changed the WB when using M?

The live view on GX85 is among the best of Pany cameras I ever used. It is small but highly responsive, in great detail, bright enough... If there is any changed in WB (same as exposure condition, saturation etc), it would never escape from our eye unless I have not looked at it hard enough.

BTW, under M, Pany camera has to switch on the "Constant Preview" in Menu. Otherwise we shall have no real time live view support like under iA/iA+/P/A/S automatic/semi-automatic shooting modes. i.e., no matter how we adjust the parameters, the simulated image in evf/LCD will always just look bright enough, but will not darken or brighten according to the setting change.

I always keep Constant Preview=On. If very slow shutter speed would be used, e.g. 1 sec, I shall set Constant Preview=OFF (in fact I have it saved in 1 of the C modes for easy call-up) because Constant Preview will also simulate the shutter speed effect. For 1 sec shutter speed the preview will has a serious lagging refresh rate of 1 sec making normal operation impossible... :-(

Wishing it might help.

--
Albert

You say you were playing with the camera, which is quite valid, and found a mistake (not checking the effect of Auto on WB) so your experiment worked and you learned something.

Now you can take it a step further. If you always set the exposure to whatever the exposure meter tells you to, you are not making use of the help that Auto is giving you. If you start learning when your exposure meter does not give a good indication and only on those cases go to Manual, then you will be using both modes to your advantage.

Some examples where lightmeters might not work well are strong backlight, moon shots, night scenes, High key (the camera has a high key scene mode, but I prefer using manual or exposure compensation in those cases).

xman111 said:

Hey guys, newbie here, of course. Just bought a GX-85 for me and my wife to play with. Tonight we were in the back yard taking pictures in auto and they looked bright and really good. When we switched to manual mode with the same settings as auto used, the pictures are, for lack of a better word, dim

Click to expand...

Are you sure your shutter speed, aperture and ISO were exactly the same? because if they were the images would have been the same.

Mark_A

Thread for Sunrise & Sunset pictures (part 3!)

xman111 said:

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Nice cat, although these "calico" varieties often have white balance issues. ;-)

Why would you want to try manual mode if the settings were the same as auto?

There's nothing special about manual mode; it's only essential in a limited number of circumstances. For your cat, I'd think about f/5.6 or f/8 to increase the DoF. I'd also consider using flash, with some EC to avoid over-exposure of the white bits.

Here's what can happen with a cat with white patches...

You can set the ISO increments to 1/3 stops and 1 stop. Apparently the default is 1 stop. See page 201 of the advanced manual on the procedure.

The exposure is not your main problem as 1/3 of a stop can be easily fixed. The WB is off in the second photo. If you are shooting JPEG WB is a very important setting as it is quite difficult to fix a wrong WB afterwards.

Panasonic has the bad habit to offer two user manuals.

For a full description of camera operation read the advanced manual:

ftp://ftp.panasonic.com/camera/om/dmc-gx85_en_adv_om.pdf

Hey guys, thanks for the responses. We just were playing around in manual mode as we haven't had a camera that has manual mode before. Thanks so much for the advance guide, i changed our settings. I downloaded the guide as well, great find, thanks!

Note that the crop on the right from one of the shots appears brighter than the crop on the left from the other shot, but when they are de-saturated their actual brightness is revealed to be nearly the same. WB (white balance) typically boosts the red and blue channels, and in one shot the red channel was boosted more relative to the blue channel and vice versa for the other shot.

Manual mode lets you shoot yourself in the foot all you want. The camera lets you decide everything.

Auto mode nerfs you from shooting yourself in the foot, and doesn't let you decide anything.

If, in Manual mode, you just want to duplicate the same exposure level the camera would make in Auto mode, just adjust your settings to put the "needle" of the light meter on "0". That's what all the auto exposure modes do by default (although the A, S, and P modes will let you dial in some compensation if you want).

If you want to make sure you have the same level of noise, depth of field, motion blur, etc., then you have to duplicate all three settings that Auto controlled: iso, aperture, and shutter speed.

Obviously, as other mentioned, white balance is another issue. Whatever you set in Manual will "stick", so if you used Tungsten last (the "light bulb" setting for indoor lighting, which cools down the yellow/orangey tones you get from incandescent lightbulbs), that's why you've got that blue cast on your other shots. Auto probably used the Shade WB, which does the opposite: warms up the shot to make it a bit more orangey.

However. If you shoot RAW and post-process in a RAW converter (e.g., Lightroom or RawTherapee), you can actually "reset" the white balance setting to whatever you want; JPEG will cook in the camera setting WB when it compresses/processes the file. You might be able to readjust the blue shot to be warmer/lighter in post to a certain degree (JPEG doesn't completely remove your ability to adjust the shot, just narrows the amount of adjustment before weird artifacts occur from the missing data that was discarded for compression).