What have you learned at NRF?

spraynpray

Hah! That is excellent seven! )

Msmoto

How true, how true… no miss takes.

sevencrossing

That promotional models, at events like photokina, are called a Booth Babes

Parke1953

Never show my wife the original only the final.

HarleyFrank

I just learned I don't need a battery in the camera (D610) when the grip is attached and has one inside. One battery is fine for my personal work. Less weight is the game for me.

sevencrossing

There is a lot more to astrophotography than meets the eye

scoobysmak

^^^^X2

Msmoto

That I do not know much...... and to be grateful for all those who help me to understand this.... )

Kellynikon

I would have expected f2.8 to be different diameters on different lenses but defined so that you could take your 18-105mm f3-5-5.6 and your 35mm f1.8 and when set at the same aperture and ISO, you would see the same shutter speed. Turns out I was wrong. ">

What? If you set (hypothetical) the aperture to F8, at iso 100. The shutter speed is the same on the 35 as on the 18-105 right? why were you wrong?

Ironheart

F-stops are theoretical (mathematical), and look at only the Focal Length and the opening of the iris. The actual light transmission, or T-stop, is a measurement of the light that moves through the lens. These two are rarely the same, and the complexity of a lens (e.g. number of elements and groups, types of glass, coatings) will have an effect on this as well. Usually the T-stop is less than (meaning a bigger number) the f-stop, DxO will give you this value for various lenses. For instance the 18-105 @ 18mm and f/3.5 has a t-stop of 5.3. The 35mm f/2 has a t-stop of 2.1

http://www.dxomark.com/Lenses/Compare/Side-by-side/AF-S-DX-NIKKOR-18-105mm-f-3.5-5.6G-ED-VR-versus-Nikon-AF-Nikkor-35mm-F2D-on-Nikon-D300___205_0_751_440

From the DxO website:
Transmission of a photographic lens describes its ability to transmit light from the photographic scene to the sensor surface. Lenses consists of many glass elements, each reflecting or absorbing a portion of the light; therefore the more elements, the lower the transmission.

Kellynikon

Ok, but if you set both the 18-105 and the 35mm to F8, there isnt a difference anymore right?

Ironheart

Yes there is. If the 18-105 loses almost a stop and a 1/3 at f/3.5, that will hold true at f/8 as well. In practice it doesn't matter, as the meter will adjust to the amount of light that the lens actually transmits.

If you compare a zoom to a prime, both at f/8 you will find that you will have different exposure values. The reason t-stops are used in the cinematography world is that typically you are cutting from one camera to another in the same scene and you wouldn't want there to be a jump in exposure value every time you switched lenses or cameras, hence the t-stop. For still photography, it doesn't matter as you are only worried about a single frame from a single lens and camera.

All f/8 means is that the opening of the iris is equal to the focal length divided by 8. It doesn't speak to the actual light moving through the lens.

Kellynikon

ah i understand, cool

Vipmediastar_JZ

I just learned what @Ironheart said.

Paperman

I have always been skeptical about photographers using handheld meters as we know they will have some error due to the different transmittence of different lenses. Camera's spot meter would give them more accurate readings. ( unless they are using it for the sole purpose of checking if light is even on different parts of the model/object )

Msmoto

I have learned that the built in matrix metering of my Nikons seems to work in about 95% of situations....when I understand my subject....

"In the old days"...LOL.... I used a Gossen Luna-Six Pro and always took ambient readings, the light hitting the subject, very much like all the folks shooting cine. From this I was able to calculate the correct exposure and was about 95% accurate. We also did readings from a remote location, same light as on subject, but when access to the actual subject was not possible.

So, what I have learned is....the new stuff is a heck of a lot easier to use IMO, and seems as accurate with appropriate adjustments..... When I remember.....LOL

Photobug

So true about technology @Msmoto.