The Learning Curve

[carrie s]

I just bought my first DSLR last weekend.I got a sony a300. My pictures are so much better now then they were with my point and shoot camera and I dont even know what Im doing yet.

 

[DueyDooDah]

I'm still trying to wrap my brain around this concept. I've been getting frustrated that some of my mid-day pictures seem overexposed. I don't know if it's me, my camera, a combination, or maybe just something I shouldn't even be bothering with.
...

Let me see if I can help.

First off, blown highlights can happen, and usually do, when there is a significant range of brightness (was called latitude in film days, now called dynamic range [hmmm, computer geeks]). Cameras do not have the ability to record all that the eye can see. According to scientists, the human eye has a latitude of 50,000. The best a film camera can do is about 500. Note that digital cameras are about the same as film cameras in their ability to capture latitude. So, what can you do to capture an image with great latitude?

First, look for angles to limit the range. Shoot from a position that does not have great brightness and darkness together.

Next, set your exposure to a spot in the viewfinder that is at the brighter end. Don't point it right at the brightest spot but something slightly darker. If you point it at the brightest spot and set exposure, you'll lose something in the darker areas. The opposite is true, also. Know that, using software in post-processing, you can recover data from dark areas easier than you can recover blown-out highlights.

Once you have set your exposure, recompose and take the shot. If it's too bright, try setting exposure to a brighter spot than before. If too dark, then aim at a slightly darker area.

Once you do this enough, you'll start to know what to look for and start compensating automatically.

One other thing you should know. Mid-day photography is also called pool-side photography. During this time of day, you should be at the pool instead of taking shots. The light is pretty bad during this time and you'll be left wondering "How come my photo just does not give me the feeling I wanted when I took it."

 

[Pea-n-Me]

Thanks, Duey. That's helpful. I've been spending a lot of time trying to figure this out. I posted on another thread that I read somewhere to "find the best light, and then find your subject matter" which is probably a good philosophy to have. This makes a lot of sense, too:

look for angles to limit the range. Shoot from a position that does not have great brightness and darkness together

These are skills I have to develop, and I'm confident I will in time.

I've also been studying some of the information on User Forums as to the particulars of my camera. There's a lot to learn, but I've learned a ton already and just have to keep at it. I'm learning from my mistakes.

 

[Pea-n-Me]

I mentioned earlier

Olympus just came out with a new 25mm f2.8 "pancake lens" on one of their newer models which I'm curious about.

I ordered it yesterday and I'm excited about it. Great price, couldn't resist. I think I'll get a lot of use out of it for portraiture, especially.

 

[Pea-n-Me]

A few recent shots from Plymouth Plantation. Constructive criticism welcomed. (The first picture is the type that I was concerned about, taken in bright, midday sun.)

This one would have been better if I'd used a tripod (or my new monopod ). Indoor shots were handheld with no flash.

 

[greggoda]

In comparing the 30mm f1.8 and the 50mm f1.8 for low light, it is the f1.8 part that is most relevant. A lower f-number means that the opening in the lens is wider and so it lets in more light. Since both of these lenses have the same f-number (f1.8), they let in the same amount of light and perform equally well in low light situations.

Newbie here but I'm an engineer so the math usually comes easier. LOL

Mark, I have a question about the statement above that because both lenses have the same f-number they let in the same amount of light. Just because both lenses have f/1.8 wouldn't the 50mm lens still let in more light and be better in situations of extremely low light?

Isn't the amount of light captured determined by taking the focal length and dividing it by two times the f number, square this result and multiply by pi to get the area. If this is correct the 50 mm would have an area of 606 square millimeters vs. 218 square millimeters with the 30 mm and would capture 2.8 times more light at the same f 1.8 stop setting when using the same shutter speed?

 

[greggoda]

Sorry - Just Subscribing

 

[Code]

Isn't the amount of light captured determined by taking the focal length and dividing it by two times the f number, square this result and multiply by pi to get the area. If this is correct the 50 mm would have an area of 606 square millimeters vs. 218 square millimeters with the 30 mm and would capture 2.8 times more light at the same f 1.8 stop setting when using the same shutter speed?

Your are correct on the area of the aperture, but you also have to consider that a smaller focal length is capturing a larger field of view.

Consider shooting the same uniformly lit wall filling the frame at both 30mm and 50mm. I could calculate the exact area of the wall captured based on distance, but I'm just after the ratio of areas, so I can just take the ratio of the focal lengths and square it. (50/30)^2 = 2.8.

The 30mm lens is capturing 2.8 times more light into a hole 2.8 times smaller, so exactly the same amount of light making it to the sensor. The f-number of a lens already takes focal length into account (f-number = aperture diameter / focal length) so it can be applied uniformly across all focal lengths as a measure of light capturing ability.

 

[Dcanoli]

Isn't the amount of light captured determined by taking the focal length and dividing it by two times the f number, square this result and multiply by pi to get the area. If this is correct the 50 mm would have an area of 606 square millimeters vs. 218 square millimeters with the 30 mm and would capture 2.8 times more light at the same f 1.8 stop setting when using the same shutter speed?

Consider shooting the same uniformly lit wall filling the frame at both 30mm and 50mm. I could calculate the exact area of the wall captured based on distance, but I'm just after the ratio of areas, so I can just take the ratio of the focal lengths and square it. (50/30)^2 = 2.8.

The 30mm lens is capturing 2.8 times more light into a hole 2.8 times smaller, so exactly the same amount of light making it to the sensor. The f-number of a lens already takes focal length into account (f-number = aperture diameter / focal length) so it can be applied uniformly across all focal lengths as a measure of light capturing ability.

Is it just me?? ...or did anyone else have to S-L-O-W D-O-W-N to read these responses?

WOW!

 

[greggoda]

Your are correct on the area of the aperture, but you also have to consider that a smaller focal length is capturing a larger field of view.

Consider shooting the same uniformly lit wall filling the frame at both 30mm and 50mm. I could calculate the exact area of the wall captured based on distance, but I'm just after the ratio of areas, so I can just take the ratio of the focal lengths and square it. (50/30)^2 = 2.8.

The 30mm lens is capturing 2.8 times more light into a hole 2.8 times smaller, so exactly the same amount of light making it to the sensor. The f-number of a lens already takes focal length into account (f-number = aperture diameter / focal length) so it can be applied uniformly across all focal lengths as a measure of light capturing ability.

Thanks Code. That makes so much more sense now. I knew I had to be missing something. Knowing that the same f-number will produce similar exposure regardless of focal length is easier to handle.

 

[greggoda]

Is it just me?? ...or did anyone else have to S-L-O-W D-O-W-N to read these responses?

WOW!

Don't feel bad Dcanoli. I had to write the question real slow too.

 

[Dcanoli]

Don't feel bad Dcanoli. I had to write the question real slow too.

YOU ARE KILLING ME HERE!

 

[Pea-n-Me]

I added some links to the lens page.

 

[dr_zero]

Neat Article about The Forgotten Lens

--------------------------------------------------------------------------------

http://www.vothphoto.com/spotlight/a...otten-lens.htm
(snippet)
Why You Should Ditch That Zoom for a Classic 50mm "Normal" Lens

So there you are, the proud parents of a beautiful new baby, and you can hardly contain your excitement as you unwrap that new 35mm camera kit you bought to document your child's early years. Although you've had a point-and-shoot camera for a while, you wanted to step up to a "real" camera for the kind of quality pictures you see in the popular media and in the camera maker's brochures. You fumble a little as you mount the 28-80 zoom lens and load the film, but pretty soon everything is ready to go.

Pea-n-Me

Good article. (I would ask that you post it on The Learning Curve thread and I'll add it to the lens section, that way we can keep all the info in one place. Thanks.)

I just purchased my first prime lens and can't wait to try it out.

 

[Pea-n-Me]

All set. Thanks for the contribution, dr zero!

I hope others will do the same if they see anything interesting that others could benefit from.

My hope is that this thread can be used as a resource guide - so please, participate!!

 

[Troop o' Goofs]

My hope is that this thread can be used as a resource guide - so please, participate!!

Too late, it already IS being used as a resource guide.

 

[Pea-n-Me]

Too late, it already IS being used as a resource guide.

Well that's good to know, thanks. I wasn't sure if it was dying out.

Would like to move forward but not really sure where to start. What subject should we tackle next?

 

[Mr._The_King]

I haven't checked in here in a while and don't know if you already covered it but how about metering(i.e. what the differnt types mean, how the camera uses them, when the best situations are for what type, what's the best "default" for general walk around photography etc.)If this was already covered my apologies and i will have to go back and find the post

 

[Pea-n-Me]

how about metering (i.e. what the differnt types mean, how the camera uses them, when the best situations are for what type, what's the best "default" for general walk around photography etc.)

I don't think we've touched on metering yet. (BTW, there's an Index in the OP now for easy reference).

I'm happy to tackle it, but seeing as it's still beyond my knowledge base I'll need some help.

Everyone - please post Metering articles you know to be helpful, and if any of the experienced users could help us out, that would be great.

 

[AndrewWG]

Metering is by far the one area that I have the most trouble with. I tend to use spot metering alot but I don't know why. I just think that the subject comes out better with spot. However, the rest of the scene suffers as the camera is only metering it's exposure from the point of focus (or possibly the center point only??). That tends to make the rest of the photo either over or under exposed. I have to really practice with the other modes more. If I'm not on spot metering, I tend to use the one that meters for the whole scene. See, I don't even know the names of them!