Low light comparisons between DSR-390 and DSR-450

[Dave Hall]

Low Light test ? 2/3? DSR-450 vs. ½? DSR-390

This is an unscientific test of the low light capabilities of the old vs. new big Sony DVCAMs. I own both cameras, although I?m currently trying to sell the 390. Both my 390 and 450 have the same equivalent wide angle Canon lens (the YH12X4.8 and the YJ12X6.5) Note that one difference between the two is the ½? Canon has a wider f-stop of f1.5 vs. the 2/3? lens with an iris of f2. That?s about a full f-stop advantage for the ½? camera right there. I tried to set both cameras for the same angle of view, and both were white balanced to 5000k (and auto black balanced) and irised wide open. I grabbed bitmaps in Premiere Pro and used Photoshop with a JPEG quality of 10 to display here. I used 100% crops at 360 x 240 pixels ? in other words you?re seeing ¼ of the video frame at full resolution. In hindsight, I accidently left the 390 with a detail setting of +20 ? I should have reset it to zero, but I?m way too lazy to redo the test! The next tests will be outdoor daytime color comparisons, plus angle of view between 16x9 and 4x3.

 

 

(above) DSR-450 at 0db gain

 

(above) DSR-390 at 0db gain

 

(above) DSR-450 at +6db

 

(above) DSR-390 at +6db

 

(above) DSR-450 at +12db

 

(above) DSR-390 at +12db

 

(above) DSR-450 at +18db

 

(above) DSR-390 at +18db

 

results: The 390 gives you about a 12db advantage, or 2 f-stops. (Compare the 450 at 12db vs. 390 at zero)

[Peter J DeCrescenzo]

What mode was the DSR-450WSL operating in: 60i, 24p or 30p? (I ask because most cams lose a stop or so when in progressive mode.)

 

Also, what shutter speed was used on each cam, or were the shutters turned off?

Edited December 29, 2005 by Peter DeCrescenzo

[Dave Hall]

What mode was the DSR-450WSL operating in: 60i, 24p or 30p? Also, what shutter speed was used on each cam, or were the shutters turned off?

 

Both in 60i, shutter off and filter wheel 1.

[Peter J DeCrescenzo]

Both in 60i, shutter off and filter wheel 1.

Thanks for the additional information. The DSR-390 is well-known for it's low-light capability; it's one of the reasons it is/was so popular for event videography.

 

The DSR-450WSL is rated by Sony as having a sensitivity of F11 compared to the DSR-390 at F13 (3200K, 89.9% reflection chart, 2000 lx).

 

Thanks for doing these tests.

[Simon Wyndham]

Only thing is, I'd like to know the technical reasons why! :)

[David Mullen ASC]

Maybe the CCD has more pixels in the same size area, which tends to reduce sensitivity.

[Peter J DeCrescenzo]

Only thing is, I'd like to know the technical reasons why! :)

I'm not certain, but the most likely reason the DSR-390 is more light sensitive is because the pixels in its CCDs may be larger than those in the DSR-450WSL. If true, that might account for the difference.

 

Both cams are rated by Sony as having the same S/N ratio spec: 65db in the NTSC version.

 

I have no idea if Sony's specs are consistent across models/years, which is why side by side comparison tests are useful.

Edited December 30, 2005 by Peter DeCrescenzo

[Guest NBC Shooter]

It would be great to know the light level in that scene, in footcandles!

 

I'm assuming the rather high-resolution chipset for the DSR450 accounts for its decreased sensitivity when compared to the 390. I'm not familiar with the 390--is that the current version of the old DSR300? Does anyone remember, or happen to have, the chip specs for the DSR500/570? I wonder if anyone knows if in fact, the DSR450 in 24psf @ 1/48th is slower than a DSR500/570 in 60i @ 1/60th? By how much?

 

Copied from the Sony site, CCD specs for the DSR450WSL:

 

Image device:

3-chip 2/3-inch type, Power HAD EX CCD

Total picture elements:

1038 (H) x 1008 (V)

Effective picture elements:

NTSC model: 980 (H) x 988 (V)

[Peter J DeCrescenzo]

... I'm assuming the rather high-resolution chipset for the DSR450 accounts for its decreased sensitivity when compared to the 390. I'm not familiar with the 390--is that the current version of the old DSR300? ...

 

The DSR-390 was the final version of the DSR3xx series of 1/2" 3-CCD full-size DVCAM camcorders from Sony. These cams have been replaced by the 2/3" DSR-4xx series. As we've discussed above, the DSR-390's high sensitivity is due, at least in part, to the relatively large size of its pixels compared to cams such as the DSR-5xx and DSR-4xx cams.

 

... Does anyone remember, or happen to have, the chip specs for the DSR500/570? I wonder if anyone knows if in fact, the DSR450 in 24psf @ 1/48th is slower than a DSR500/570 in 60i @ 1/60th? By how much? ...

 

The sensitivity spec for the DSR-570 (which is a 60i-only camcorder) is f11 at 2000 lx, the same as the for the DSR-450WSL in 60i mode. When the DSR-450WSL and most other true progressive-capable camcorders are in progressive mode, they typically lose about a stop or so of sensitivity.

 

It's important to note that the S/N ratio spec (and perhaps more importantly, _visual_ results) for whichever cams are being compared should be taken into account when comparing sensitivity performance. For example, you might have two cams whose sensitivity are rated f11 at 200 lx, but one may do so with a noisier image compared to the other.

 

These comparisons should ideally be conducted at the same time, under identical lighting and circumstances, viewed on the same _one_ properly calibrated broadcast (or at least pro) monitor, and so forth.

[Guest NBC Shooter]

Yeah, I understand that a given sensitivity spec comes with a given (i.e. arbitrary "0 dB") noise level. What I was asking was that since the DSR500/570 series CCDs have a (presumably) lower pixel density than the new DSR450, which has a surprisingly high pixel density, which would, on face value, make the DSR450 less sensitive than the DSR500/570 with its larger pixels (progressive-mode sensitivity issues, aside).

Edited January 3, 2006 by NBC Shooter

[Peter J DeCrescenzo]

Yeah, I understand that a given sensitivity spec comes with a given (i.e. arbitrary "0 dB") noise level. What I was asking was that since the DSR500/570 series CCDs have a (presumably) lower pixel density than the new DSR450, which has a surprisingly high pixel density, which would, on face value, make the DSR450 less sensitive than the DSR500/570 with its larger pixels (progressive-mode sensitivity issues, aside).

The NTSC DSR-570WS has an effective pixel element spec of 980 x 494 (H x V). Its typical S/N spec is 63 db.

 

The NTSC DSR-450WS has an effective pixel element spec of 980 x 988 (H x V). Its typical S/N spec is 65 db.

 

As mentioned above, they're both rated by Sony as having a sensitivity of f11 at 2000 lx.

 

Hope this helps.

[Guest NBC Shooter]

So whaddya think? More pixels in the 450 CCDs--gotta be smaller pixels, right? Maybe a 1/2 stop slower, when both are in 60i?

[Peter J DeCrescenzo]

So whaddya think? More pixels in the 450 CCDs--gotta be smaller pixels, right? Maybe a 1/2 stop slower, when both are in 60i?

I'm not sure what you're referring to, regrets. Sony's sensitivity spec for the DSR450WSL and DSR-570 is the same (f11 at 2000 lx), and the DSR-570 is noisier by 2 db.

[Simon Wyndham]

Just to thrown another cat amongst the pigeons interestingly the SDX900 and SPX800 are rated at f13 at 2000 lux.

[Peter J DeCrescenzo]

Just to thrown another cat amongst the pigeons interestingly the SDX900 and SPX800 are rated at f13 at 2000 lux.

Yes, because these 2/3" cams have much lower-res CCDs (approx. 1/2 megapixel) with relatively large pixels compared to the 1-megapixel 2/3" CCDs in the DSR-4xx and PDW-5xx cams.

[Simon Wyndham]

Interesting. So now there is a flipside to discuss. What we are gaining from 1mp CCD's compared to 0.5mp ones when recording to SD resolution.

 

Hehe, Walter would have a fit if he was reading this thread now ;)

 

But the numbers beg the question. After all the Sony cameras are sacrificing a lot of low light performance, so it would be interesting to know what is being gained.

[Brian Wells]

It is surprising this camera doesn't do HDV -- it seems like the perfect candidate in all other ways. More res than a HVX200, yet still standard definition.

[Simon Wyndham]

Well, it's not quite as simpleas that. I can't remember the reasons, but despite a 1mp CCD it still only equates to 720x576 (PAL) usable resolution.

[Tom Wills]

I can personally attest to the fact that the DSR 390 is one incredible camera. I use one at work, and we film sporting events. You should see the kind of locations we have to shoot in sometimes. It's a workhorse camera, with a great low-light performance, and it has incredible image quality.

 

The DSR450 having more pixels is a little strange, because I can't see the quality boost being that great considering 2 full stops of light loss.

[Peter J DeCrescenzo]

... The DSR450 having more pixels is a little strange, because I can't see the quality boost being that great considering 2 full stops of light loss.

It's a bit of an apples & oranges comparison. The DSR-450WSL is a 2/3" cam (with the depth of field characteristics of a 2/3" cam) and does both progressive and interlaced shooting, whereas the older DSR-390 is a 1/2" cam and interlaced only. The DSR-450WSL delivers much higher resolution (native) 16:9 video compared to cropped 16:9 from a DSR-390. The higher resolution CCDs in the DSR-450WSL may enable it to produce somewhat more accurate color compared to lower-res cams.

 

Plus the DSR-450WSL has other features not found in the older DSR-390 and DSR-570 models.

 

So, the DSR-390 has an "advantage" only if one wants to shoot 4:3 in interlaced mode and in low-light situations, and you have no need for the DOF capabilities of a 2/3" cam. Of course, the DSR-390 was considerably less expensive than the DSR-450WSL (and DSR-570).

 

I bought my DSR-450WSL because I wanted as much flexibility as possible in a 2/3" DVCAM camcorder for under $20K US (with a lens, SDI output option, & lens controller).