Nature Photographers Network
This is the preserved archive of the original Nature Photographers Network. The community continues at naturephotographers.network.

Hmmm...

Discussion

6 replies
Posted by Alison on May 25, 2006 at 12:38 PM
Well, today I went and bought myself a sigma 70-300mm f4 - 5.6 lens for my Pentax ist DL2.

Just for a change, the weather has been lovely so I took advantage and set off out with my camera and lovely new lens.

Figured it was a good idea to go to a familiar place where I have taken loads of good shots in the past with my old camera (z5). I happily took loads and loads of shots of the ducks, some flowers, blackbird, magpie, trees etc etc. Felt quite pleased with myself and headed on home.

Well, really, this is probably the worst set of photos I have taken in my entire life! lol! Camera shake on virtually every shot (Lesson 1, use the damn tripod) and most of the shots were either underexposed or overexposed and I don't mean by just a little! lol!

I am laughing about it as there is no point crying but one thing I am finding difficult is the LCD on the camera makes it very difficult for me to tell if I have the correct exposure.

The LCD itself is very bright and what looks nicely exposed on there is very dark on my pc monitor (I know there is nothing wrong with the monitor by the way). I can adjust the brightness on the LCD so do you all think this would be a good idea or should I try and work with the brighter setting it's on as default and try and learn to guage it? My concern is that if I reduce the brightness, I might end up with all overexposed shots. Oh well, guess all I can do is try!

Sorry for wittering on, just thought it really funny how I had so many failed shots! lol!

Alison
Posted by Nick on May 25, 2006 at 12:51 PM
Alison,

There could be a couple of things wrong, it's difficult to say without seeing your photos for comparison or the shooting data for them.

A couple of quick suggestions:

1) Make sure you haven't accidentally set the camera to under/over expose!
2) Your camera's LCD is to bright.
3) Your monitor is not properly calibrated.
4) The lighting is fooling your cameras metering & you need to override it yourself.

Does your camera allow you to display a "histogram" / graph which shows the exposure of the photo. If it does, then try using that to evaluate the exposure - if the histogram is biased mainly to the left hand side, then you are potentially underexposing, otherwise if biased to the RHS - then you are potentially overexposing. The level of under/over exposure depends on how cramped the graph is towards any one side.

Your monitor is a bit more difficult to check out...do you have a colour calibration sensor or do you use Photoshop?
Posted by Nigel Blake on May 25, 2006 at 12:52 PM
You really need to get to grips with understanding the histogram display on the monitor, this graph will tell you how acurately the image is exposed better than looking at the image does.
As a quick guide you need the main peak of the graph to be in the centre of the grid. The link below should give a little better expaination.

http://www.dummies.com/WileyCDA/DummiesArticle/id-3286.html
Posted by Peter Barritt on May 25, 2006 at 12:54 PM
andy rouse seems to suggest the historam should fit slightly to the left of centre and this is what I aim for. The histogram is the only useful part of the LCD when shooting outside IMHO.
Posted by Alison on May 25, 2006 at 5:22 PM
Ooh, thanks for the histogram tips. Now all I need to do is work out how to use it! lol! I'm very new to DSLR, very very new so have a long way to go yet.

I have checked my monitor callibration and that's just fine, I know there is nothing wrong with the camera and that it's the operator who is naff! lol!

The lcd is very bright on the Pentax so I might try lowering that a bit as well as the histogram. Hopefully that will help me get better exposure.

And of course, will remember to use a tripod in future for those 300mm shots! lol!

I never realised just how different the DSLR would be to the Dimage Z5. With the Z5 at full zoom, without image stabilizer, I seldom got camera shake so expected it to be as easy with the new camera. However, I am fast learning that this is going to take more skill, which at the end of the day, was the whole idea of having a dslr as opposed to the non slr cameras.

I'll get there eventually. Not posting any of me failed shots, they are too much of an embarrassment! lmao!

Thanks again for the tips, I will read the manual later on and try and learn as much as possible about the use of the histogram before I go out with the camera again.

Alison
Posted by Jeremy on May 25, 2006 at 8:12 PM
To avoid camera shake when handholding, try to use a shutter speed at least the equivalent of the focal length you are using. For instance, with your zoom extended to 300mm, try to use a shutter speed of at least 1/300th of a second.
Good luck!
Posted by David J Slater on May 28, 2006 at 5:20 PM
It may be that your lens is broken - ie stuck at its widest aperture. I had this once with Sigma. It's difficult to really mess up exposure with digital - like child's play compared to film, so I'm guessing equipment failure. Is your lens compatible with the body (sometimes Sigma lenses need re-chippping to work properly with the body)?

By the way, the histogram advice above is misleading. The main peak in a histogram (if there is one) simply reflects the tone of the most numerous "colour" in the image. Not all histograms have only one peak. In a correctly exposed shot, it's only in the middle if most of the image is mid tone (i.e. mid green or mid red), and to the left by one-stop if most of the image is dark green or dark red etc). It's to the RHS if it's mainly snow in the image, and to the LHS if it's a night sky. Main thing is that the histogram isn't "clipped" off either end. But this doesn't matter too much if your into manipulating your shot, just so long as the histogram isn't truncated or "clipped" off one side or the other..