Jon01 From United Kingdom, joined Jun 2001, 116 posts, RR: 0 Posted (9 years 11 months 1 week 1 day 17 hours ago) and read 1197 times:
I will shortly have a Nikon D100. I understand due to the size of the CCD a 1.5X factor is added to the lens. So when looking through the viewfinder do you see what the lens is actually seeing, or is the viewfinder magnified or cropped to allow for the 1.5X magnification?
I know that the latest Contax N and Canon 1DS have full (35mm) frame CCD/CMOS so there is no magnification issue with these models.
Jon01 From United Kingdom, joined Jun 2001, 116 posts, RR: 0 Reply 1, posted (9 years 11 months 1 week 1 day 17 hours ago) and read 1180 times:
I am assuming that you cannot preview a shot in realtime with the LCD on this model.
Just found this info on the web relating to the D100:
Viewfinder frame coverage Approx 95%
Viewfinder magnification Approx. 0.8x with 50mm lens set to infinity and -1.0 m-1
Tsentsan From Singapore, joined Jan 2002, 2016 posts, RR: 16 Reply 3, posted (9 years 11 months 1 week 1 day 16 hours ago) and read 1151 times:
On the D100 and all other digital SLRs, WYSIWYG is in place. When you look through the viewfinder, you effectively have the 1.5x magnification in place. IE, you use 200mm (on your lens) to photograph the image. You are actually looking at it as through you are using 300mm (1.5x 200=300mm)for it.
D100 gives as stated 95% framing, which means that what you see on the viewfinder is 95% of the entire image. I think the higher end models give u up to 99% framing.
Jon01 From United Kingdom, joined Jun 2001, 116 posts, RR: 0 Reply 4, posted (9 years 11 months 1 week 1 day 15 hours ago) and read 1124 times:
OK, so the viewfinder must have it's own 1.5X magnification lens or the mirror is the same size as the CCD to compensate, otherwise a standard size mirror will reflect the standard lens image to the viewfinder and not show what the CCD is seeing.
Ckw From UK - England, joined Aug 2010, 530 posts, RR: 18 Reply 6, posted (9 years 11 months 1 week 1 day 13 hours ago) and read 1103 times:
is the same size as the CCD to compensate
Yes, this is the case - the camera body is designed around the sensor and has been "scaled" to provide the same optical pathways as a normal SLR - much in the same way that APS or 110 SLRs were scaled.
Glennstewart From Australia, joined Jun 2003, 1124 posts, RR: 56 Reply 8, posted (9 years 11 months 1 week 1 day 10 hours ago) and read 1073 times:
There isn't any magnification in the viewfinder. The DSLR's (with smaller than 35mm sensors) have cropped viewfinders. You will notice a difference if you look in the viewfinder of a standard film SLR to a cropped DSLR (I say cropped, because 35mm sized sensors are found in DSLR's such as the Canon 1Ds - this doesn't have a cropped view finder).
Why the cropped viewfinder?
The image itself is cropped due to the small sensor, so the viewfinder should be cropped accordingly.
Why the cropped sensor?
I assume manufacturing costs of larger sensors (the price of the Canon 1Ds is prohibitive).
What does that mean for the image?
35mm SLR's are designed to have light projected onto the size of a 35mm film. The lenses are designed for the ground up to project to an area this size. By attaching the same lens to a DSLR, the same light is projected back onto where the film would normally sit. The DSLR sensor is smaller and hence surrounding light is lost that would normally be captured by film. This leads to cropping compared to film.
A 300mm shot taken on my Canon 10D gets cropped by 1.6x = 300 x 1.6 = 480mm. The perspective is exactly the same as seen by a 300mm lens so isn't the same as attaching a 500mm zoom lens.
This can best be explained by attaching a fish-eye lens to a DSLR.
Attach a fish-eye lens to a film camera and the barrel like distortion is noticiable as a border around the corners. With a DSLR, attaching a 17mm lens that would cause distorsion on film has a similar Field of View as a 28mm lens, but with a draw back - it maintains the distorsions of the 17mm - albeit excluding the corners - the worst part.
Glenn Stewart
Sydney, Australia
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