lalon_karim

<p>I think nobody here will deny that D700 has a sensor that has lower noise in higher ISO than 5D Mark II. What we are trying here is to figure out what it translates into (lower noise 12MP vs higher noise 21MP sensor) in terms of output. Here is a quote from dxomark.com article: ".....Moreover, the measuremnt above corresponds to 1:1 viewing conditions on a screen. Except for image retouching and examining details, this is probably not useful way to view the image. A fit to screen viewing or a print on a given-size paper format is a more likely use case." And the noise comparisons in high ISO that are done in dpreview use JPEG, not RAW (personally I do not have any objection though).</p>

<p>Thank you all for your responses. What surprises me is that the change in effective focal length is very noticable with this lens and I didnt read about it in any review. If I am not wrong, at 55 mm, when focused to a distance of 4ft, it works like an 68mm lens (gives the coverage of 110mm lens instead of 88mm in 35 mm equivalent). That's a huge difference!</p>

Help! I own a 450D/ Rebel XSi. Today (May 16, 2009) I bought a EF-S 55-250mm f 4-5.6 lens. This is not an internal

focusing lens (front of the lens rotates while focusing). My interest is portrait photography and this lens covers two

traditional portrait focal lengths 65mm (105 mm equivalent) and 83mm (135mm equivalent). But I found out that if a

leave the lens at any focal length (55, 70, 100, 135, 200, 250 etc) and than focus (manually or auto), the perspective/

angle of coverage changes. That is, for a same subject at a same distance using a same focal length, the closer the

distance I focus, the viewfinder (and final image) shows a tighter angle which means the focal length increases. The

focal length ring does not rotate while it happens.

Why is it happening? Is it normal? Does anyone have any experience regarding this? As far as I know, it may

happen to internal focusing lens. But why is it happening with this lens?

<p>Here is a link that is very useful for caluclating DOF for any camera/ focal length/ subject distance: <a href="http://www.dofmaster.com/dofjs.html">http://www.dofmaster.com/dofjs.html</a></p>

 

<p>Just to clarify it further, I want my camera to give perfectly usable (for print) high ISO result without any post processing. This is what I tried to mean.</p>

<p>Landrum, by "perfect", I didn't mean lifelike. I donno the proper words to define it, but it actually means something like - "can give excellent print in terms of color, sharpness and noise without further post processing". And it's true that photography is an art. A photographer does not try to show what we actually see. Instead he tries to show what he wants us to see. That is what art is about . And I myself is very fond of high ISO photography. Thank you for your opinion, Landrum.</p>

<p>This is just a personal opinion, but I do not like post processing that much. Every camera should have a "standard" setting for color, contrast and noise reduction that should produce "perfect" result for printing straight out of the camera. For advanced users, who like post processing, there sholuld be other settings available (muted/ neutral and high/low noise reduction etc) or they can shoot raw. Just like we do not frame carelessly thinking that we will crop later- "perfect" outputs straight out of camera can give a lot of pleasure. </p>

<p>Errr... Jamie, thank you for your response. but I really dont think that for the same sized print 5D Mk II has better high ISO performance than D3X. There is a good chance that it is actually other way round. (I dont have any proof, but you may see this link: <a href="http://www.kenrockwell.com/nikon/d3x/iso-6400-5d-mark-ii-d3.htm">http://www.kenrockwell.com/nikon/d3x/iso-6400-5d-mark-ii-d3.htm</a>). D3X has recommended ISO upto 1600 because it is designed as a studio and landscape camera - not necessarily because it has worse high ISO performance.<br>

Apart from this, I agree with what you wrote.</p>

Here is an interesting link, though it may not look like directly related to the current topic, it actually is:

http://www.dxomark.com/index.php/eng/Insights/More-pixels-offsets-noise!

From imaging-resource.com:

 

About 5DMkII: http://www.imaging-resource.com/PRODS/E5D2/E5D2IMAGING.HTM

"At higher ISOs, the 5D Mark II's images held together surprisingly well. For 13x19 inch prints, ISO 6,400(!) was about the limit, as the noise in shadow areas began to be noticeable at that size, and detail was obliterated in areas of subtle contrast. This is really a remarkable performance from a camera with this much resolution: Comparing their images side by side, prints from the Canon 5D Mark II at ISO 6,400 were quite comparable (similar or slightly higher luminance noise, lower chroma noise, a bit softer overall) than those of the EOS-1Ds Mark III at ISO 3,200"

 

About D700: http://www.imaging-resource.com/PRODS/D700/D700A5.HTM

"High ISO images were really extraordinary: Together with the D3, the Nikon D700 clearly leads the field in high-ISO performance, thanks to its large pixels, CMOS sensor technology, and Nikon's excellent noise-reduction processing. D700 images shot under incandescent lighting (always the tougher test) looked great when printed at 8x10 inches, all the way up to ISO 6400. At ISO 6400 and at that size, there was a little noise present, but we had to look close to see it (closer than you'd normally view a print of that size), and it was very fine-grained. - There's also almost no chroma component to the D700's noise at ISO 6400, making it even less apparent than noise patterns from many other cameras with similar "grain" size. Shot under daylight-balanced lighting and printed at 13x19 inches, the D3's ISO 6,400 shots were softer and somewhat noisier than those at lower ISOs, but the results were still pretty amazing."

<p>I have no expertise on these things, but I think the best way to compare cameras with different resolution is by making same sized prints. dxomark.com and imaging-resource.com do this type of comparison.</p>

Sample<div></div>

I use 50mm f/1.8 with my 450D. It works as a 81mm lens for my camera. It gives great results for portraits compared to 18-55mm kit due to it's large aperture. But if I have the choice, I would buy a prime lens that would work as 105mm lens on my camera (a 65 mm lens will do this job). Too bad that Canon and Nikon do not take cropped sensor body users seriously.

As far as I understand, ISO 3200 images from 50D are usable with NR set to high. But ISO 6400 and 12800 are good for nothing.

If I have to say based on spec sheets, 50mm f/1.2 for APS-C and 85mm f/1.2 for full frames (I havent use any one of those).

If I had a full frame body, it would be 85mm f/1.2.

For my APS-C camera, it will be 50mm f/1.2!

<p>Here is the answer:<br />1. The new camera will have 100% viewfinder coverage with around 0.74x magnification<br />2. It will have completely weather proof body like D3/ D3X<br />3. It will weigh about same as D90<br>

4. It may have something like eye detection autofocus!<br />This is actually more like my wishlist!</p>