A question for the Nikon owners amongst us

[ian s. forsyth]

<p>Did you ever wonder what happens to the light that falls outside of the cropped sensor, with FF I can simply scale my FL by 1.5 capture that light and add it to my total exposure (gather more light)</p>

[personalphotos]

<p>No you are wrong Ian. I read enough to know <em>I don't care</em>, to be polite. It has nothing to do with good photography.</p>

[andy_coach]

<p>ahem...<br>

<img src="http://olivebranchdaycare.net/images/index.1.gif" alt="" width="360" height="308" /></p>

<p>:)</p>

[ian s. forsyth]

<p>I did as you asked 1 photo shot at 50mm F5.6 on DX and the other FF 50mm F5.6 wow boy did I get it wrong they look the exactly the same, captured the same amount of light for the given sensor.<br>

D800 50mm F5.6 @ 100sec iso 100</p>

<p><img src="http://isfphotography.smugmug.com/photos/i-zGvvFbK/0/XL/i-zGvvFbK-XL.jpg" alt="" /><br>

K5 50mm F5.6 @ 100sec iso 100<br>

<img src="http://isfphotography.smugmug.com/photos/i-rrT2pb6/0/XL/i-rrT2pb6-XL.jpg" alt="" /><br>

<strong>But they are not as anyone can see</strong><br>

You would have to overlook 1 of the 3 fundamental parameters in capturing an image (Field of View ) the other 2 being Perspective and Depth of Field. There is no way these would be consider equivalent photos without them having the same FOV.</p>

<p>To make them TRUE equivalent I would have to change the focal length of the one of formats ( using a 75mm on FF) to match the same FOV but in doing so I change the Depth of Field 1.3 stops shallower because that image is being projected onto surface twice the size of the DX . So to correct this I would have to stop down the lens 1.3 stops to give it the same DOF restricting the of amount per unit of light fall on the surface of the sensor but because the sensor is twice the size and gathering 1.3 stops more light offsetting this 1.3 stops in DOF adjustment. So what does this mean<br>

DX @ 50mm F5.6 100 sec = FF @75mm F9 100sec<br>

2 photo sharing the same FOV, DOF and perspective. This is what is meant by Equivalance </p>

[michael_kuhne]

<p>Well, the Sigma 10-20mm is exceptionally compact for a lens of its focal length range in APS-C design, but it is not a fast lens. What is a good trick to pull off for an average-speed APS-C lens becomes an impossibilty when it comes to fast glass, in the WA to normal range, trying to match the equivelent FL of a full-frame setup. For instance, don't look for a Pentax DA FF equivelent of the FA 24mm f/2 (DA 16mm f/2), or FA 35mm f/2 (DA 24mm f/2) anytime soon, and expect they'd be as compact and lightweight as those FA lenses. The DA 21mm Limited is a very nice lens, and in a remarkably compact pancake body, but it is f/3.2- big difference from f/2. And how about the FA 43mm f/1.9 Limited pancake lens? A DA 28mm f/1.9 Limited of similar size?? Ain't gonna happen.</p>

<p>Closest we can get to a compact fast normal APS-C equivelent is using the FA 35mm f/2 as a manifestation of the old 55mm f/2 standard normal. Forget about a fast WA. Pentax should re-establish that 35mm lens in all its FF glory, but as a DA 35mm f/2 WR designed for digital use. Ditto for the FA 24mm f/2 in the form of a DA 24mm f/2 WR. Maybe as DA* lenses, with superior construction. I say in their FF glory, because just in case a FF DSLR should eventually come into the Pentax lineup. And use on film bodies would also be a good option to have. This has been the case with other DA* lenses, like the DA* 200mm f/2.8, a very fine lens. Pentax needs to improve their SDM technology, however. The silent AF employed in the DA 18-135mm is different, and appears to be quite good, with no reports of failure so far, that I have seen. Pentax might be better off after all just reissuing those lenses calibrated for digital just as DA WR, and using the plain old screw-drive AF. This would make the lenses more affordable, and accessable for film body use. </p>

<p>I best enjoy my FA 43mm 1.9 Limited and FA 35mm f/2 lenses on one of my compact film bodies, for the FOV they present, coupled with their speed, small size, and quality performance. In addition, the film bodies are considerably lighter than a DSLR, even a DSLR of APS-C type, let alone a FF DSLR! Even the best of my film compact bodies, the metal-construction MZ-S, is far lighter!</p>

<p>When it comes to the tele range, the shoe is on the other foot. A FF lens of 70-200mm f/2.8 for instance is much bigger and heavier that its APS-C equivelent Pentax or Tokina 50-135mm f/2.8 lenses.</p>

<p>Nikon does make an exceptonally good-performing, nice 24mm f/1.8 FF lens. If that is a primary interest for you, and you aren't happy just shooting film with a lens of that focal length and speed, a FF DSLR is the logical solution.</p>

[miserere_mei]

<p>People keep harping on about the small size of the D600...but I don't get it. See with your own eyes, the D90 compared to the D600:</p>

<p>http://camerasize.com/compare/#179,378</p>

<p>And the K-5 compared to the D600:</p>

<p>http://camerasize.com/compare/#187,378</p>

<p>The D600 is <em>NOT</em> a small camera, even if it might be <em>slightly</em> small by FF standards.</p>

<p>Just sayin'...</p>

[miserere_mei]

<blockquote>

<p>Ian wrote:<br>

Or look at it this way for pentax to have the equivalent to the 24-70 F2.8 it would have to be 16- 45 F1.4</p>

</blockquote>

<p><br />Just a small niggle: according to your definitions the 16-45mm would have to be f/2, not f/1.4.</p>

[personalphotos]

<p>Mis, yes it's still quite big and if you compare it to the D700, there's very little difference. Most of that is a few mm in width and the larger 'flash hump' on the D700.</p>

<p>Just for fun, compare the D600 to the D3s. Users who own that beast can see a huge difference (of course to be fair, you would need to add a grip to the D600).</p>

<p> </p>

[personalphotos]

<p>Andy, I know this tangent has derailed your thread a little and this will be my last post responding to Ian. But I can't help but reply at least once more. I will freely admit I make mistakes and assumptions from time to time and others have corrected me. When one is not open minded enough to realize one's mistakes, forums get filled with theory's posted as absolute facts and someone coming by a year from now might read this an assume it's correct.</p>

<p><strong>The rest of you can ignore this:</strong><br /> That being said, Ian, I know you will post again and assert you are right. I won't reply because this thread is about enjoying and lusting over a new camera. It's been hijacked too much already. I'm as much to blame and now but in for a penny, in for a pound....</p>

<p>Re your last 2 photos. You try to prove a point by using different brands of equipment, different flash systems possibly (we don't know) and meter value settings and you set the cameras up differently. You should be using a constant light source, not flash or strobe.</p>

<p>1) Pentax and Nikon metering calibration are going to be slightly different (look at Canon where it can be +/- 1/2 stop at times!) Thus your example is flawed.</p>

<p>2) You posted the wrong EXIF data on the exposures....</p>

<p>3) The Nikon was set to -0.33 EV and the Pentax was set to 0.0 EV. That's a 1/3 stop variance! Example is now worthless.</p>

<p>4) The Jpeg controls for brightness and contrast settings for each camera were set differently. Plus who knows how each manufacturer determines those settings and their relative values to the exposure. Thus your example is further flawed.</p>

<p>5) You are using different lenses on each camera. To prove your exposure assumption, you should use the same lens on each and be set to the same equivalent value. IE 50mm (FOV 75mm) on the APSc and 75mm on the FF. Using the same zoom lens on each would allow this. On top of that, using a different FOV allows different reflected light into the image captured, changing the exposure. Further flawed.</p>

<p>Respond if you must but I'm unsubscribing to this thread and will not reply. Let Andy enjoy his craving for a new camera.</p>

<p> </p>

[ian s. forsyth]

<p> It was you that jump in when I was showing the K5 and D800 side by side illustrating size differences with 2 formats that are setup to take similar photos with nearly the same DOF FOV illustrating that with equivalent lenses on a FF body on most part are smaller and cheaper and most of the time negating the size and cost of a FF body when a person needs several lenses.</p>

[andy_coach]

<p>Thanks everyone for your input, it's been an education thread for me, very appreciated. I've decided to wait until the next time I get the impression that my Pentax kit is lacking in some respect before letting my appetite for a new Nikon overtake me. The other thing that's helping me put the breaks on may sound trivial but I just can't get over the so-so grip design on the D600, compared to the K-5 grip, which I find just about perfect. Still, I have my dream D600 kit almost fully dream up. </p>

[wtlwdwgn]

<p>If you haven't made the plunge yet you might see if LensRentals has what you want and try it out before you spend all your savings on CBA and LBA. :~D</p>

[andy_coach]

<p>Not a bad idea.. I checked the prices at LensRentals, not bad at all, and their policies are very common sense. Thanks for the tip.</p>