Older lens mount compatability

[Chuck Tribolet]

If the effective focal length is changed from full frame to "DX" size sensors then it must as well alter the effective F stops mathmaticaly. F8 on the apeture ring would not really represent F8 but something greater depending upon the magnification.

Not true. The actual focal length does not change, so the f/ stops remain as accurate
as ever. What changes is the "35 mm equivalent focal length", or field of view.

 

[Larry C]

The plus side of this is that on the D300, my MF 400mm becomes effectively a 600mm. The minus side is that if you're shooting wide angle lenses, a 12-24 becomes effectively an 18-36. In order to get close to 180 degree coverage, you have to go down to an 8 or 10. The other issue would be reversing the interchange. If you get one of the new DX lenses designed for the 1.5 crop factor, they won't cover the full sensor on a full frame model. OTOH, if you were using a 4/3 model like the new Olympus offerings, the crop factor is 2-1. They have to offer a 6mm fisheye to match the 12mm full frame WA lens.

 

[Nemrod]

Not true. The actual focal length does not change, so the f/ stops remain as accurate
as ever. What changes is the "35 mm equivalent focal length", or field of view.

Thank you, I see that now. I just had to do the math to convince myself and I do believe you are correct. It is an apparent change due to the smaller sensor, not a REAL change in focal length. N

 

[Nemrod]

The plus side of this is that on the D300, my MF 400mm becomes effectively a 600mm. The minus side is that if you're shooting wide angle lenses, a 12-24 becomes effectively an 18-36. In order to get close to 180 degree coverage, you have to go down to an 8 or 10. The other issue would be reversing the interchange. If you get one of the new DX lenses designed for the 1.5 crop factor, they won't cover the full sensor on a full frame model. OTOH, if you were using a 4/3 model like the new Olympus offerings, the crop factor is 2-1. They have to offer a 6mm fisheye to match the 12mm full frame WA lens.

The digital formats are weird. "They" chose 4:3 for most digital cameras because that was the aspect ratio of television and most computer screens. Now most televisions and computer screens are 16:9 which is much closer to the original 35 MM format. BUT, even with the majority of digital cameras having a 4:3 aspect ratio, most printers do 4X6 detc prints which results in severe cropping of the image when printed. Is this not ridiculous or what? "They" need to pick a (ccd sensor size) format and 16:9 makes sense since that is closer aspect ratio to most MODERN televisions and computer screens (and 35MM film) and suprisingly te same as 4X6 prints. What the hades is up with the square format 4:4 and 4:3. Nobody is still using tube televisions and square computers.

N

 

[Chuck Tribolet]

16:9 makes sense since that is closer aspect ratio to most MODERN televisions and computer screens (and 35MM film) and suprisingly te same as 4X6 prints. What the hades is up with the square format 4:4 and 4:3. Nobody is still using tube televisions and square computers.

16:9 isn't close to 6:4 (ie, 4x6 print). 16:9 would be 7.1111x4

If sensors are cheap, square format becomes interesting. You don't have to turn the
camera to take a vertical. And sensors will get cheaper and cheaper. Now, the down
side of square sensors in dSLRs is a more massive mirror and pentaprism. And the low
end of point and shoot isn't going to want to crop in the computer and doesn't have the
sense to rotate the camera when taking the pictures.

There's a niche market for vertical (portrait) computer montors and a video cards. If you
deal with paper a lot, they are good. BTW, the first digital imaging I dealt with (1973)
was portrait. 100 dpi was typical, 200 dpi if we wanted coffee while it processed,
1 bit per pixel (pixels were black, or white, and we didn't call them pixels, they were PELs).

 

[Nemrod]

Fotogenetic - 35mm Film and the Golden Rectangle

No, but I would rarther have blacklines on my TV edges than having all hte heads lopped off on my prints.

None of the standard print sizes are exactly the same aspect ratio as 35MM film but they generally result in less than the .5 inch that is getting lopped off by 4X6 prints when you print the standard P&S aspect ratio.

Aspect Ratio and Cropping to the Proper Print Proportions

My basic point is now that 16:9 seems to be a standard of sorts since it is a common movie aspect ratio, the standard television aspect ratio and the aspect ratio of most new computer monitors shouldn't we adopt a format that will display on the media and it would print well on standard issue 4X6, 8X10 etc instead of the typcial digi camera 4:3 aspect ratio.

N

 

[Chuck Tribolet]

None of the standard print sizes are exactly the same aspect ratio as 35MM film but they generally result in less than the .5 inch that is getting lopped off by 4X6 prints when you print the standard P&S aspect ratio.

35mm full frame uses an image area of 24mm x 36mm, which is exactly the same aspect
ratio as 4x6 prints and 8x12 prints. Do the math.

 

[Nemrod]

35mm full frame uses an image area of 24mm x 36mm, which is exactly the same aspect
ratio as 4x6 prints and 8x12 prints. Do the math.

Yeah, I confused myself, yawn, I guess I am just imagining the loss of image when I print 4:3 to 4X6 prints.

A not very good picture as it prints typically on my three photo printers:

The actual file before being auto cropped:

In this case it is not a big deal but it often results in loosing portions of the image that were of interest.

Sort of Photoshopped:

It does not show well but I was trying to get the reflection which looked impressive to my eye but did not translate well to an image.

N