EFcoins wrote:.
Using a lense on a digital camera has a different effective focallength to using it on a 35mm film camera.
Sorry, wrong. The focal length does not change, but the field of view does..
I have a 90mm Tameron Macro lense, on a Cannon EOS-10 film camera.If the lense has to be 200mm from the subject To fill a 35mmnegative, how far away will it need to be with a digital camera(canon 400D perhaps), to fill the sensor?.
Multiply the focal length of your lens times the crop factor to get new field of view.90*1.6=144.
An actual distance would be great, but closer/further/same would begood as well.
Chris, Broussard, LA..
Not sure what you are telling me. What significance does the 144 have, the original distance 200mm must come into the calculation somewhere..
The new field of view is equivalent to a 144mm lens, so you need to back up.math:90/144=x/200 restated: 144x=90(200) or x=12.5.
I would suggest 125mm from subject with your crop camera to get the same field of view..
I am sure those on here who know math better than me can correct my math..
EFcoins wrote:.
Not sure what you are telling me. What significance does the 144have, the original distance 200mm must come into the calculationsomewhere.
Chris, Broussard, LA..
Sorry, I will redo the math and get back to you.Chris, Broussard, LA..
Add roughly 125mm from your subject to compensate for the reduced field of view. 200*1.6=320mm..
I will quit doing math now. I hope this helps. I really am trying..
Bikinchris wrote:.
The new field of view is equivalent to a 144mm lens, so you need toback up.math:90/144=x/200 restated: 144x=90(200) or x=12.5.
I would suggest 125mm from subject with your crop camera to get thesame field of view..
I am sure those on here who know math better than me can correct mymath..
EFcoins wrote:.
Not sure what you are telling me. What significance does the 144have, the original distance 200mm must come into the calculationsomewhere.
Chris, Broussard, LA.
Chris, Broussard, LA..
If it really is equivalent to a 144mm lense, then I thinkx = 200 * 144/90 = 320mm.
You seem to have demonstrated that the effective focal length really has changed.
Thanks..
EFcoins wrote:.
If it really is equivalent to a 144mm lense, then I thinkx = 200 * 144/90 = 320mm.
You seem to have demonstrated that the effective focal lengthreally has changed.
Thanks.
What he's saying (and he's right) is that the focal lenght does not change, rather the crop changes. To save myself energy, my camera has a 1.5 factor. Meaning that a 100mm lens will have the same "Crop" as a 150mm lens. It's not real magnification, it's a closer crop done in camera. So this means that the subject will appear the same with a camera with no crop factor and a 150mm lens as my camera with a 100mm lens. BUT, the the actual 150mm lens has more resolving power than the cropped view of the 100mm lens..
Hmm confusing?.
Try this linkhttp://www.dpreview.com/.../?/Glossary/Optical/Focal_Length_Multiplier_01.htm.
Finally, all of the above refers to dSLR's. With digcams it's an entirely different ballgame. Those lenses even though referred to in the same manner as dSLR lenses, actually do have the resolving power. They are more like miniature lenses and focal lenght equivalents are not relevant..
Dave..
EFcoins wrote:.
If it really is equivalent to a 144mm lense, then I thinkx = 200 * 144/90 = 320mm.
You seem to have demonstrated that the effective focal lengthreally has changed.
For calculating field of view, you can treat it as a 144mm lens. But for other purposes, such as calculating depth of field, it's still a 90mm...
Chato wrote:.
...It's not real magnification, it's a closercrop done in camera. So this means that the subject will appear thesame with a camera with no crop factor and a 150mm lens as mycamera with a 100mm lens..
"appear the same"??? - Won't the depth-of-field be different and thus appear different? (more noticeable the larger the aperture).
Good Day,Roonal.
'Money doesn't buy happiness, but it makes for an extravagant depression' by golf tournament sportscaster..
Roonal wrote:.
Chato wrote:.
...It's not real magnification, it's a closercrop done in camera. So this means that the subject will appear thesame with a camera with no crop factor and a 150mm lens as mycamera with a 100mm lens..
"appear the same"??? - Won't the depth-of-field be different andthus appear different? (more noticeable the larger the aperture).
I left out the DOF.... .
Dave..
As that is soley based on camera to subject distance. Simply cropping the image at 200 feet will not give the same picture as an uncropped image at 320 feet. The perspective is completely different..
Cropping an image does not chage the focal lenght or even the effective focal length. The focal length is a function of the lens only..
Rich..
RichW wrote:.
As that is soley based on camera to subject distance. Simplycropping the image at 200 feet will not give the same picture as anuncropped image at 320 feet. The perspective is completelydifferent..
Cropping an image does not chage the focal lenght or even theeffective focal length. The focal length is a function of the lensonly..
Cropping the image with a lens, effectively increases the clarity of the image. It does this by putting more pixels on the target than a later crop in an image processing program. While the ability to resolve detail remains the same, whatever detail that CAN be resolved will be clearer with the cropped sensor. So a 100mm lens on a sensor with a 1.5 factor will have much greater clarity than the same lens on a Full framed sensor(all else being equal)..
Dave.
Rich..
Because you have less light on the image with a smaller sensor. This discussion can go on forever, but I'll leave it at that..
Bottom line is you are not changing the focal length by using a smaller sensor and the images are far from being equal..
Rich..
RichW wrote:.
Because you have less light on the image with a smaller sensor.This discussion can go on forever, but I'll leave it at that..
Bottom line is you are not changing the focal length by using asmaller sensor and the images are far from being equal..
Rich.
While it is quite true that at higher ISO's Canon camera's have less noise than Nikon, this doesn't seem to have any relationship to sensor size. All Canons are less noisy than Nikons. But at lower ISO's? Up to 400? Do you really think that the larger sensor is less noisy? I know of no one seriously making that claim..
Dave..
It's very basic as explained on page 5:.
Http://www.robgalbraith.com/...ic_files/Canon_Full-Frame_CMOS_White_Paper.pdf.
A few other articles:.
Http://www.dmcphoto.com/Articles/SensorSize/index.html.
Http://www.pictureline.com/newsletter/article.php?id=331.
A search will give many more discusions explaining the reasons the larger sensors and larger pixels create less noise..
Rich..
RichW wrote:.
It's very basic as explained on page 5:.
Http://www.robgalbraith.com/...ic_files/Canon_Full-Frame_CMOS_White_Paper.pdf.
A few other articles:.
Http://www.dmcphoto.com/Articles/SensorSize/index.html.
Http://www.pictureline.com/newsletter/article.php?id=331.
A search will give many more discusions explaining the reasons thelarger sensors and larger pixels create less noise..
Rich.
I don't dispute a theoretical benefit at high ISO's I dispute your statment that noise in a factor that even deserves to me mentioned when I made my point. Here is what I posted:.
"Cropping the image with a lens, effectively increases the clarity of the image. It does this by putting more pixels on the target than a later crop in an image processing program. While the ability to resolve detail remains the same, whatever detail that CAN be resolved will be clearer with the cropped sensor. So a 100mm lens on a sensor with a 1.5 factor will have much greater clarity than the same lens on a Full framed sensor(all else being equal).".
So are you disputing my point? And on what basis are you disputing my point? That at ISO's above 800 noise will be a factor in photography? Good for you, under those conditions, noise will interfere with good quality..
On the other hand, my Nikon D2x puts TWICE as many pixels on my target as the Canon Mark II 1Ds. So if one needs to do this kind of photography, which would be the better choice?.
You've named a disadvantage of a smaller sensor. Fine. It has NOTHING to do with my point at all..
All it does is allow you to show your knowledge. Vunderbar! My congratulations..
I have nothing against people adding information to my posts. And you could have made your point in a manner that adds to the discusion instead of confusing the discussion. And that's what you did with your post. Instead of adding knowlege you detracted from knowledge. Sorry, I have little patience with someone who feels compelled to dispute a valid point because there are additional relevant facts..
Dave..
Chato wrote:.
RichW wrote:All it does is allow you to show your knowledge. Vunderbar! Mycongratulations..
Not knowledge, but re spewing the party line to make sure that NO ONE will ever forget that Canon has a sensor the same size as the old 135 film frame. nevermind that the vast majority of cameras sold by Canon company do not have 135 sized sensors..
I have nothing against people adding information to my posts. Andyou could have made your point in a manner that adds to thediscusion instead of confusing the discussion. And that's what youdid with your post..
Exactly, thanks for pointing this out. He had no interest in the discussion, but saw it as a place to insert his point..
Instead of adding knowlege you detracted fromknowledge. Sorry, I have little patience with someone who feelscompelled to dispute a valid point because there are additionalrelevant facts..
The OP asked what distance should he mo to to fill his frame with his 1.6 APS sensor. Answer the question, add to the dicsussion (something meaningful) or start your own thread, please..
Chris, Broussard, LA..