Originally posted by normhead What? The exposures didn't work? The images aren't the same, but the exposure worked. That's the point. You can use one camera as the light meter for the other, in fact I several times used the *ist as an exposure meter for older film cameras. Because ƒ4 is ƒ4.
If you want to talk about DoF that's different.
Of course exposure is the same, but exposure with a digital camera is dead simple. The camera does it automatically, I adjust EV when required, and if not, I can very easily change brightness in post. I need to control everything else. I was trying to blur the background, like he did in the book, or close my aperture down to make sure the entire landscape was in focus.He was somewhat aware of equivalence because he said if you have a digital body, you should use one less stop than his film camera. Which would have been fine if I was shooting APS-C. Imagine the diffraction I was causing, shooting a tiny sensor compact camera at f/16.
I know you understand equivalence theory, Norm. You don't see the use of it, and Northrup's presentation style riles you up.
Equivalence explains a lot of things that confuse newbies, and from this discussion, there are still plenty of experienced photographers who do not understand or are unwilling to understand what it is, and what is not. Manufacturers play on the lack of understanding by using equivalent focal lengths with real apertures. The RX10 IV has an 8.8-220mm f2.8-4 lens. It is
not 24-600mm f2.8-4. Converting to FF equivalent focal lengths must also include equivalent apertures in order for me to understand the camera's operating parameters, I can calculate that the RX-10 has a
24-600mm f8-11 FF equivalent lens. Now I can compare it's operating range with my K-3 and DA 55-300mm f4.5-6.3 PLM, which is
83-450mm f6.8-9.5. Or with my DA*300mm with 1.4X RC, which is
630mm f8.4. That's a pretty impressive compact but for $2500 CA, I'll pass.
Originally posted by normhead If you want the same images as someone else, buy exactly what he has. You have to do that anyway. Messing around with thinking equivalence will get you exactly the same image is a myth. It will get you in the ballpark, but after that, other variables will take over. IN that sense, there is no such thing as equivalence. Just some ball park numbers that don't take into account variations in lens design and how distance from the camera affects the image.
For equivalence:
- Shutter speed, exposure and distance from the subject (perspective) must be the same
- Focal length and aperture must be adjusted for crop factor
- Sensors must be of similar technology (current sensors quality within 1/3 stop, the exception being Foveon)
- Resolution will vary depending on number of pixels and lens sharpness
- FOV, DOF, DR, perspective, diffraction and noise will all be similar. For me, this is where the meat is, and it is explained by equivalence theory, not by the exposure triangle.
.
I cannot do what a K-1 does with an FA 50mm f1.4 at widest apertures, using my K-3 and FA 35mm f2. I can get similar images from f2.8 and up. Sure, there will be some differences but the photos will be very similar in the parameters that I control and that matter most to me.
Originally posted by normhead Audiobomber is also Dan.
The more Dans the merrier.
I get it though, I hate it when there's another Norman in the room.
There are
always two Dans. Everywhere I go, two Dans. My best friend growing up was a Dan. At work there were two Dans. Believe it or not, TwoDan1 is my Outlook email address.
Originally posted by Kunzite I don't know about the two D FA macros, but I'm sure the DA* 200mm, DA* 300mm and DA560mm became worse just as Ricoh Imaging announced they're actually full frame lenses.
I don't think there's much doubt that the D FA 100mm macro would have been smaller, less expensive and just as capable if it had been designed for APS-C. Long telephotos don't seem to vary much, the recent 300mm f4 lenses for Nikon FX and m4/3 are pretty similar in same size nd weight. The new 11-18mm f2.8 would be much larger and more expensive if it were designed for FF. The D FA 50mm f.1.4 would be smaller and cost less if it was a DA* lens. The reason that Pentax has the most complete stable of APS-C lenses is because we did not have a FF body. Fuji is rapidly catching up with its lens environment for the same reason, whereas Pentax now needs to pump out FF lenses.
Originally posted by Lord Lucan While I have read this thread (and contributed) i have only just looked at that video.
What a load of tripe. The only thing i don't understand is how someone can talk such nonsense with such an air of confidence. Isn't he aware that he does not understand his subject?
BTW, he refers to a measure by dxomark of "perceived megapixels", but I could not find any reference to this measure on the dxomark website. Can someone give a dirct link?
What is it specifically that you don't agree with in the video? What is it about equivalence that you don't get?
Here is an explanation of Perceptual Megapixels:
Perceptual Megapixel: Lens Sharpness Boiled Down to a Single Number
DXOMark, lens testing protocols:
DxOMark lens testing protocol and scores - DxOMark