Sunday, January 25, 2009

D300 and D700 Equivalent Images with Pro Glass

I had more than a few comments from people disagreeing with my statement that the Nikkor 70-200 VR did not perform well on the D700. Well, for photos that do not have walls with uniform light color as a background, it does perform really well. I guess those complaining about my statements about the 70-200 on the D700 had a point. It does work better on the D300...

The whole thing made me curious about the equivalent images that can be attained with the D300 and D700 paired with higher end Nikkors. The pairs of images below were all hand held. The images are not "strictly" equivalent since I used aperture priority with auto ISO set according to focal length, and with two stops shutter speed compensation for lenses with VR. So at a focal length of 130mm on the D700 with VR lens, I set the minimum shutter speed to as close to 130mm/4 as possible. Whereas at 85 mm on the D300 with a non VR lens, I set the minimum shutter speed to as close to 85mm*1.5 as possible. The top ISO before violating my minimum shutter speed requirement was set at ISO 3200 for the D300 and ISO 6400 for the D700. I tried my best to frame the pictures similarly.

Nikon D300, Nikkor 85mm f/1.4D, f/2, 1/80 sec, ISO 280

Nikon D700, Nikkor VR 70-200/2.8G, 116mm, f/3.2, 1/20 sec, ISO 200

The VR 70-200mm f/2.8G and the 85mm f/1.4D are both awesome lenses. If you compare the two images you can see a little bit of the vignetting on the 70-200 image, but it wouldn't otherwise be noticeable. I had a very hard time focusing both images on the exact same location. My intention was to focus on the hanging fish's left eye. However, since the focus sensor on the D300 is much bigger (relatively), it actually focused between the blue part just below the eye and the table top. The D700 was able to focus between the white and black parts of the eye. With the depth of field about 1 cm deep, this makes a difference when you look at the images at 100%. Anything faster than f/2.8 in the normal and above focal range appears to very rarely be necessary on the D700. Very easy to make mistakes.... In any case, the 85/1.4D at f/2 seems to be (as it should, being a prime) sharper than the VR 70-200/2.8 at f/3.2. The noise advantage, however, goes to the D700 due to the two stop help from the VR.

D300, 24-70/2.8G, 56mm, f/2.8, 1/30 sec, ISO 2500

D700, 85/1.4D, f/4.5, 1/30 sec, ISO 6400

The 24-70/2.8G is also a great lens. This time the 85/1.4D is on the D700. The 85/1.4 shows just a tad more contrast, but otherwise the images have near identical noise and Bokeh.

Nikon D300, Nikkor 85/1.4D, f/2, 1/125 sec, ISO 560

Nikon D700, Nikkor VR 70-200/2.8G, 130mm, f/3.2, 1/30 sec, ISO 450

Among the two images above, the D700 + 70-200 are sharper, with more contrast, and significantly less noise.

D300, 24-70/2.8G, 32mm, f/2.8, 1/40 sec, ISO 2500

D700, 50/1.4G, f/4.5, 1/40 sec, ISO 6400

Comparing the above two images, the D700 + 50/1.4G is sharper in the center, but otherwise nearly the same in every other aspect.

D300, 14-24/2.8G, 23mm, f/2.8, 1/50 sec, ISO 2500

D700, 35/2D, f/4.5, 1/50 sec, ISO 6400

Comparing the above two images, the D700 + 35/2D are just a bit sharper but otherwise the images are very similar.

D300, 35/2D, f/2.8, 1/40 sec, ISO 2500

D700, 24-70/2.8G, 52mm, f/4.5, 1/30 sec, ISO 6400

Between the above two images, the D700 + 24-70/2.8G is a bit sharper and more contrasty with similar noise levels.

More D300 and D700 with the super zooms

Some readers of my previous post where I compared the Nikon D700 with Tamron 28-300 VC against the Nikon D300 with Nikkor 18-200 VR, asked for equivalent images of the Tamron on the D300. Below are four equivalent images with all combinations of the two lenses and cameras.

Nikon D300, Tamron 28-300 VC, 50mm, f/4.5, 1/8 sec, ISO 1000

Nikon D300, Nikkor 18-200 VR, 50mm, f/4.8, 1/8 sec, ISO 1000

Nikon D700, Tamron 28-300 VC, 78mm, f/7.1, 1/8 sec, ISO 2500

Nikon D700, Nikkor 18-200 VR, 75mm, f/7.1, 1/8 sec, ISO 2500

The best of the four is the D700 with the Tamron. However, when looking only at the D300 images, the Nikkor outdoes the Tamron. These images were taken on a tripod in a fixed position with constant interior lighting at night time. If you have some theory as to why this happens, please let me know.

Saturday, January 24, 2009

Tamron 28-300 on D700 vs Nikkor 18-200 on D300

In my previous post I compared the Nikon D700 and D300 cameras using the concept of equivalent images. In that test I used a single lens, the Nikkor 70-200mm VR, to compare images from the two cameras. I used the same lens because that was my only way to obtain near perfectly matching Fields of View (FoV) - the D300 and D700 are slightly different size, and placing them on a tripod does not give the same perspective. However, with the 70-200 I was able to mount the lens to the tripod and therefore get much closer FoVs. The problem with my comparison images in the previous post is that the Nikkor 70-200 is much better suited for DX than for FX.

In a more realistic scenario, you would use equivalent (not the same) lenses on each camera to really see the differences. Here, I attach a Tamron 28-300mm f/3.5-6.3 VC to the D700, and the very popular Nikkor 18-200mm f/3.5-5.6 VR to the D300. The lenses are not exactly equivalent, since the D300 would require an 18-200mm f/2.3-4.1 for equivalency, but are representative of actual choices available.

In these comparisons, I did not use a tripod. I did not force equivalency to extreme levels either. Rather, tried to capture the same image by setting the cameras using aperture priority (1 and 1/3 stop down for the Tamron), and getting as close as I could to equivalent focal lengths. I set both setups with auto-ISO's that attempt to maintain at least 1/30 sec. I set the maximum ISO on the D700 to 6400, and on the D300 to 3200. Thus, in at least one of the comparisons, there is significant shutter speed difference. I think this kind of comparison captures much better what could be expected in actual use.

D300, Nikkor 18-200 VR, 2000mm, f/5.6, 1/30 sec, ISO 1251

D700, Tamron 28-300 VC, 300mm, f/9.0, 1/30 sec, ISO 3200

In the pair of images above the D700+Tamron are a clear step up to the D300+Nikkor. Less vignetting, sharper. Just looks better.

D300, Nikkor 18-200 VR, 48mm, f/4.5, 1/30 sec, ISO 1600

D700, Tamron 28-300 VC, 78mm, f/7.1, 1/30 sec, ISO 4500

In the two images above, the D700+Tamron improve on the D300+Nikkor even further. Less noise, better colors, sharper, and no flaring.

D300, Nikkor 18-200 VR, 135mm, f/7.1, 1/30 sec, ISO 2500

D700, Tamron 28-300 VC, 210mm, f/9.0, 1/25 sec, ISO 3200

I goofed in trying to set up equivalent images in the comparison above, but this is bound to happen in regular use as well. The D700+Tamron should have been stopped down to f/11, not to f/9. So the depth of field should have been larger and a larger ISO should have been required. Nonetheless, the D700+Tamron are a definite step above in sharpness, color, and noise.

D300, Nikkor 18-200 VR, 150mm, f/10.0, 1/13 sec, ISO 3200

D700, Tamron 28-300 VC, 220mm, f/16.0, 1/6 sec, ISO 6400

This is another case where the D700+Tamron clearly outdo the D300+Nikkor in every possible aspect. This is despite a full stop difference in shutter speed, an indication of the significant effectiveness of Tamron's VC (Vibration Control).

D300, Nikkor 18-200 VR, 50mm, f/4.8, 1/30 sec, ISO 720

D700, Tamron 28-300 VC, 78mm, f/7.1, 1/30 sec, ISO 1600

In the two images above, the D700+Tamron show off yet another area where they improve the D300+Nikkor: Constrast in addition to lower noise and sharper images.

I hope this practical comparison has shed some light on the currently available super flexible walk-around options. I use mostly Nikon glass, but the Tamron 28-300mm VC attached to the D700 clearly outperforms the Nikkor 18-200mm attached to the D300. The Tamron has yet another characteristic that was not explored here - it is a macro lens too (it can do 1:3 magnification at 300mm)!

Thursday, January 22, 2009

Nikon D300 vs D700

Nikon's D300 and D700 digital SLR's are very similar state-of-the-art cameras that differ mostly in their sensor format. The D300 uses a cropped DX sensor (23.6 mm x 15.8 mm) whereas the D700 uses a full frame FX sensor (36.0 mm x 23.9 mm). Both sensors contain about the same number of photosites, roughly 12 megapixels. Due to sensor size differences, the D700's photosites are about 2.31 times larger than the D300's photosites. This allows the D700 to perform at significantly lower noise levels at higher ISOs. The D700 is also about US$ 1000 more expensive than the D300. It is a bit larger and heavier, and requires the use of FX lenses (the D300 can use DX lenses which are typically smaller and lighter).

What is the difference between these two cameras, in practical terms? What do I get in return for the extra cost, size and weight of the D700 vs the D300? It boils down to the different focal lengths, apertures and ISO levels that are required to achieve equivalent images in the two cameras, and the quality of the resulting images. Equivalent images are those with the same Field of View (FoV), Depth of Field (DoF), perspective, and exposure.

Crop Factor

The crop factor of the D300 is the ratio of the D700's diagonal to the D300's diagonal. This turns out to be 1.5215. A value of 1.5 is commonly used.

Field of View (FoV)

As shown above, the view captured in the DX crop is smaller than that captured by the FX sensor when the same lens and focal length are used. In order for the DX sensor to capture the same view, the focal length has to be reduced by the crop factor as illustrated below. Thus, in order to obtain the same FoV, the focal length used in the D700 should be approximately 1.5 times the focal length used in the D300. For example, the D700 at 300mm and the D300 at 200mm offer the same field of view .

Depth of Field (DoF)

The depth of field is the distance between the point nearest to the camera that is considered to be in focus, and the point furthest away from the camera that is considered to be in focus. This concept is excellently described in Wikipedia, including the formulas that can be used to calculate it.

An analysis of the formulas, under the reasonable assumption that the focal length is very small when compared to the distance between camera and subject (the point theoretically in perfect focus), leads to the conclusion that in order to maintain the DoF constant between the two images with equal FoV (e.g., the D300 at 200 mm and the D700 at 300 mm), the f-number used for the non-cropped image should be increased by a factor equal to the crop factor. So, extending the prior example, the D700 at 300mm, f/3, and the D300 at 200mm, f/2, offer the same Field of View and Depth of Field.


Increasing the f-number by the crop factor is equivalent to stopping down by a number of stops equal to the base 2 logarithm of the crop factor squared (1.21). So to achieve the same Depth of Field, the D700 must use 1.5 times the focal length and the aperture must be stopped down by 1.21 stops relative to the D300. In order to obtain the same exposure, the D700 image must decrease the shutter speed by 1.21 stops, or increase the ISO by 1.21 stops. Assuming hand held shooting, the shutter speeds should remain constant for equal shake-induced blurriness, so the only recourse is to increase the ISO by 1.21 stops (multiply by the crop factor squared, or 2.31). Thus, equivalent images can be obtained with the D300 at 200mm, f/2, ISO 800, and the D700 at 300mm, f/3, ISO 1880.

Thinking in terms of lenses

I like to look at this in terms of lenses. What lens do I need to use in the D700 to get images equivalent to those produced by the Nikkor 18-200mm f/3.5-5.6 in the D300? I would need a 27-300mm f/5.3-8.4, and would need to use an ISO increased by a factor of 2.31 (1.21 stops).

Looking at it in the other direction may make the relationship clearer. What lens do I need to use in the D300 to get images equivalent to those the Tamron 28-300mm f/3.5-6.3 provides on a D700? I would need a 19-200mm f/2.3-4.2, but would be able to use a smaller ISO, decreased by a factor of 2.31 (1.21 stops).

Assuming you are a D300 user, what enjoyment, size, weight, and cost would you associate with an optically perfect Nikkor 16-46mm f/1.8? Well, you can get equivalent images from a D700 and a Nikkor 24-70 f/2.8.

On the other hand, in order to get images equivalent to those from a D300 with a Nikkor 200-400m f/4, you would need to attach a Nikkor 300-600mm f/6 to the D700.

Image quality

Equivalent images do not imply equal quality even assuming lenses with equivalent optics. The noise levels and vignetting may differ, and for either of these what is better may not be obvious. How does the noise level of a D300 at ISO 800 compare to the noise level of a D700 at ISO 1880? While vignetting may be higher when the lens is attached to a D700 than when attached to a D300 using the same focal length and aperture, does stopping down 1.21 stops and increasing the focal length by a factor of 1.5, when attached to a D700, compensate for this? Further, most lenses perform better when stopped down, so insofar this is true, that will improve the quality of a D700 image relative to the equivalent D300 image.

In order to test these ideas, I set up a Nikkor 70-200mm f/2.8 on a tripod. I attached the D300 and took pictures with focal lengths set to 70, 80, 90, 102, and 120 mm, and with apertures from f2.8 to f7.1 in 1/3 stop increments. Then, without moving the tripod or 70-200, I attached the D700 and took pictures at focal lengths set to 105, 120, 135, 150, and 180 mm; and apertures from f4.5 to f11 in 1/3 stop increments. I took a total of 45 pictures with each camera.

The apertures I used in the D700 to match the D300 were 1 and 1/3 stops smaller. For each D700 image, the focal length, aperture, and ISO ideally required to produce an equivalent image are listed below the actual values used for the image. The calculations used to determine the ideal parameters use the true crop ratio, and explicitly consider the ratio of focal length to subject distance, rather than assuming it is negligible. The focus in all images is set to the number "6" in the green "six ball", which was 9.5 ft away from the camera. All pictures where taken in manual exposure mode at 1/8 second, letting the camera adjust the ISO appropriately with auto-ISO. Auto white balance was used in all cases. Below are 4 pairs of equivalent pictures along with comments. If you click a picture you will be taken to Picasa Web Albums, where you can download 1600 pixel images.

Comparison 1

D300, 80mm, f3.5, 1/8 sec, ISO 400

D700, 120mm, f/5.6, 1/8 sec, ISO 900
(required for Equivalency: 121.7mm, f/5.41, 1/8 sec, ISO 954)

A comparison of the two images above, clearly shows that the D700 version suffers from significant vignetting compared to the D300 image. This is a known deficiency of the Nikkor 70-200 when used with FX sensors. Peeping at the two pictures side by side, will show that the even at ISO 900, the D700 image has noticeably less noise than the D300 image at ISO 400. In the center, the D700 image is sharper, but this is probably due to the fact that the lens performs better at 120mm f/5.6 than at 80mm f/3.5. It also appears that the DoF of the D700 image is a bit larger, although the "10" in the "10 ball" looks crisper in the D300 image. Overall, with the exception of the vignetting, very similar images.

Comparison 2

D300, 90mm, f/4.5, 1/8 sec, ISO 640

D700, 135mm, f/7.1, 1/8 sec, ISO 1400
(required for Equivalency: 136.9 mm, f/6.96, 1/8 sec, ISO 1532)

The differences between these two images are similar, but not as pronounced, as between the first pair. The D700 still has noticeably more vignetting. One change is that the DoF of the D700 now appears to be a bit narrower.

Comparison 3

D300, 102mm, f/7.1, 1/8 sec, ISO 1600

D700, 150mm, f/11, 1/8 sec, ISO 4000
(required for Equivalency: 155.2 mm, f/11.01, 1/8 sec, ISO 3849)

These two pairs of images are very similar. The D700 still shows a tad more vignetting. The noise levels are almost identical. The D300 is a little sharper at the center, but again probably due to better lens performance at 102mm than at 150mm

Comparison 4

D300, 120mm, f/2.8, 1/8 sec, ISO 280

D700, 180mm, f/4.5, 1/8 sec, ISO 640
(required for Equivalency: 182.6 mm, f/4.36, 1/8 sec, ISO 678)

Again the images are very similar.


The D300 and the D700 perform close when outfitted with lenses capable of delivering equivalent images. To obtain equivalent images, the D700 must use a lens that has 50% larger focal length, and about one and a third stop slower. You may not be able to find a lens for the D700 that can provide equivalent images to the D300 with a super telephoto attached. Similarly, you may not be able to find a lens fast enough and wide enough to attach to the D300, that will provide images equivalent to those attainable with the D700 and a fast normal or wide lens. Both are great cameras. If you want to have it all, then you need both.