Two days per week at the Idaho Falls Humanitarian Center but now temporarily (I hope) closed by the virus scare..

Are you viewing this while wearing polaroid glasses by chance??

Very interesting! I was there in the navy years ago. Pretty place!

Not to get too techy but I think one is still using all of the lens but only the center part of the image cast by it which normally would be the best part.

We use DB for cloud storage in a Humanitarian Org where we have multiple users. We have had some near misses. If someone deletes or corrupts a file somehow, that deletion/corruption will propagate throughout, so you need to have backup! On one occasion we were only saved by finding one synced machine that happened to be turned off at the time and was thus unaffected by the deletion. We then learned what we should have already known that we should backup all important files/photos outside of the synced folders, even separately on a non synced backup computer. In such a multi user setup like this, you be vulnerable unless you keep copies outside of the synced folders.

We use DB for cloud storage in a Humanitarian Org where we have multiple users. We have had some near misses. If someone deletes or corrupts a file somehow, that deletion/corruption will propagate throughout, so you need to have backup! On one occasion we were only saved by finding one synced machine that happened to be turned off at the time and was thus unaffected by the deletion. We then learned what we should have already known that we should backup all important files/photos outside of the synced folders, even separately on a non synced backup computer. In such a multi user setup like this, you be vulnerable unless you keep copies outside of the synced folders.

[quote=oldtigger]if you remove a file from drop box, does it remove only the file in the drop box folders or does it remove the file from all your folders, drop box and/or otherwise?[/quote

Adding, deleting or editing files and/or photos in DB will propagate through all devices synced to the same DB account. No files outside of the synced folders will be affected. Try it for yourself.

OK, look at this
http://electronics.howstuffworks.com/camera1.htm

We often read on this and other forums that one advantage of using a FX lens on DX body is that the image then intercepted by the DX sensor is created by just the center part of the attached FX lens. The fact is that every part of the image created by any lens on any sensor is created by every part of the lens, otherwise it's not a very good lens. To understand, draw a picture of a simple lens, and a subject and a sensor. Light reflected from any point on the subject will radiate out and a small part of it will strike the lens, all of the lens. The lens, unless window glass, will refract this light from wherever it strikes the lens to a spot on the sensor corresponding to the point on the subject. A point at the edge of the subject image that would be recorded on a FX sensor may well be beyond the edge of a DX sensor, in this case, but every part of the lens would still contribute to it.

Ok, I don't believe that using an FX lens on a DX body results in just using the "sweet part" of the lens, the image still uses all of the lens whatever it's type. Every part of a lens contributes to every part of the image cast, it's just that the DX sensor only intercept the middle part of the image created by an FX lens. I don't see why that would necessarily improve the image quality.

I think you would be using all of the lens regardless of the sensor size; the full frame lens would just cast a larger image circle than the crop sensor would intercept. Every part of the lens contributes to every part of the image and that's unrelated to the size of the sensor.

Thank you. D800 and Sigma 150-500 and a Toyota 4-Runner quadpod with a 2-elbow head. The Ospreys have taken over a nesting site along a highway near our house. I'd love to build one of these nests in my back yard but we're probably too far from water for Ospreys.

I didn't realize they nested so late. The owls around here are already hatched. Hope this works. If I can't find the add..., there will be another post.

OK, we're photographing a pinhead placed in the center of our image. Reflected light from the pinhead goes lots of places including the entire surface of the lens on our DX, or any other, camera. So what happens to the light from the pinhead that strikes the edge of the FX lens? Why wouldn't it be refracted right back into the image just as well as the light striking the center of the lens.

First post, hope I'm doing this the right way??

I have, it seems, read many comments suggesting that only the center of an FX lens contributes to the image created when it's mounted on a DX body. Unless I'm wrong, every part of a lens contributes to every part of the image and when an FX lens is mounted on a DX body, only the center part of the image cast is captured by the DX sensor but that every part of the lens has contributed to it. There may still be less edge distortion from whatever source but it's not because part of the lens is uninvolved.