G9 and ISO 400

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Much is made of the fact that the G9 is a bit noisy and that noise increases at high ISO settings. In general, I agree. But I disagree with the oft-stated wisdom that the G9 is horrible or, at the very least, unusable above ISO 200. Although I’ll grant that the condemnation or acceptance of noise is largely a matter of taste, I find the G9 to be very usable at ISO 400 – especially if shot in raw mode, properly exposed and processed with noise reduction software. This shot of balloons is from the G9 in raw mode, ISO 400, 1/60 second, f5 using bounce flash. It was converted in Adobe Camera Raw, slightly cropped and tweaked in Photoshop CS3. Noise reduction was accomplished with Noiseware immediately after conversion from raw mode. The Noiseware setting was simply the default.

In my opinion, the G9 produces reasonable 8x10 prints at ISO 400 when shot in raw mode, converted in ACR and treated with Noiseware. In this digital age, many people do not print their photos and, if printed, most photos are printed as snapshots. I’ve posted a 1024x768 pixel version (full screen for many) of the balloons on my Smugmug gallery.

Of course, your mileage – and tastes -- may vary and I have no idea of the noise characteristics of the new G10. But if you have a G9, don’t be afraid to use ISO 400. At the very least, try ISO 400; you may be pleasantly surprised. (In fact, sometimes I use ISO 800 but that's another story ...)
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A Few More Seconds

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Mike Johnston’s The Online Photographer is one of the sites that I check daily. Mike has another site, Photoborg, which is currently featuring old cameras and family snapshots. Photoborg articles have a short story or description along with the picture.

Yesterday’s Photoborg feature, my granddaughter Wesleigh, gives me a few more seconds towards my allocated fifteen minutes of fame.
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G10 Announced

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Today Canon announced the Powershot G10 as the replacement for their G9. The G10 had been anticipated for months although there was much debate about the name and features. My own predictions – not perfect, but not too bad – were made in late July.

There are good summaries and preliminary reviews at Imaging Resource and DPReview . I’m sure those same sites will soon have more complete hands-on reports and sample pictures. Full size sample pictures from Canon have been posted although all are at ISO 80.

As for my own predictions, my biggest surprise is that the G10 has a new, wider angle zoom lens: 28 – 140 mm (using 35mm equivalent). I appreciate the wider angle even though some photographers wanted an even longer telephoto than the 210 mm of the G9. It was good to see Canon responding to the need for a wider angle zoom.

I probably will not be getting a G10. Although I’m sure that the G10 will be a good camera and it has some nice features – especially that wider angle lens -- the G10 is not really a major upgrade to the G9 for those who already have a G9.

This Light Description blog is sometimes said to be specific to the G9 but it really isn’t. My intention for Light Description has always been to create a platform for presenting my photographic thoughts, experiences and results as well as simply learning how to write a blog. In getting the G9 last year, I noted that equipment was not the limiting factor in my photographic efforts. Of course, since then I’ve bought more equipment – including the G9! I’ve thoroughly enjoyed learning to use the G9, pushing it to the max for performance, and blogging about the experience. In fact, I’m still learning to use my G9.

I use my G9 in some way nearly every day and have taken nearly eight thousand pictures with it. But I’ve used video only a few times, the voice recorder only once, and haven’t used the special scene settings at all. I have plans to test and write about the various exposure modes, light metering modes, more about noise reduction and high ISO, more about HDR , raw processing, software, etc., etc. I’m very interested in learning to use off-camera flash. Much of these thoughts and experiences will also apply to other cameras, especially the G7 and, I assume, the G10.

So Light Description will go on. Everyday several hundred readers check in; most readers have been particularly interested in the G9. Those G9’ers will see the emphasis continue on the G9 for a while and then gradually shift to general techniques even though the camera being used will probably be the G9.

But I really do like cameras …

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G9 File Size

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The image produced by the G9 is 4000 pixels x 3000 pixels for a total of 12 million pixels. We say that the G9 is a 12 megapixel camera; I usually write this as 12 MP. So a G9 image file would be 12 megabytes (MB), right? Well, not necessarily and probably never exactly.

The in-camera JPEG file produced by the G9 is roughly 5 MB in size for the “Large, Superfine” description. Page 261 of the G9 manual gives estimated file sizes for the various JPEG and RAW settings but these are only estimates. The file sizes are smaller than might be expected because, as noted previously, JPEG files are not only compressed but also are lossy; that is, some data is discarded during the compression process. The results of the mathematical algorithm for lossy compression vary with the content of the image file. In other words, file size varies with the picture so you never know the file size until after the picture has been taken.

To see for myself how the file size varies, I put my G9 on a tripod and photographed a mundane scene of my messy bookcase – which you will not get to see. I set the G9 on Large, Superfine JPEG, wide angle, manual exposure at 1/10 second, f2.8, auto white balance and took 22 pictures. Why 22 pictures? Well, I varied the contrast, sharpening and saturation for every picture. File sizes ranged from 4561 KB to 5741 KB. Remember: the scene and lighting was identical for each picture.

Using My Colors, I varied the Custom Color setting for contrast, sharpening and saturation. For those settings, considering the mid-point (“Normal”) as being zero (0), I took pictures at the low extreme, the Normal and the high extreme; I think of these settings as being -2, 0, +2. Here are some examples of files size:

Cont Sharp Sat Size, KB
0 0 0 5142
-2 -2 -2 4596
-2 -2 0 4561
-2 0 0 5070
0 +2 0 5532
0 0 +2 5265
+2 +2 +2 5565
-2 +2 +2 5741

In comparison, a RAW file was 13,600 KB and the accompanying JPEG at Large+Fine (not Superfine) was 3089 KB when the settings were 0, 0, 0.

A quick linear regression analysis shows that the amount of sharpening has the most significant effect on file size, followed by saturation. Contrast has the least effect on file size. (Note: The linear regression does not provide an exact match. It predicts the smallest file size at -2, -2, -2 and the largest at +2, +2, +2; however, the correlation is pretty good.)

My explanation? Sharpening tends to increase apparent detail and those details – whether real or not – are not as compressible. I was a little surprised by the effect of saturation and contrast. I actually thought that reduced saturation and contrast might increase the file size but this was not the case. Finally, there is a cross correlation between these three variables but it is not very significant with regard to file size.

My conclusion? I still shoot mostly in RAW mode. When I do shoot in JPEG, I usually leave the contrast, sharpening and saturation at “Normal” but this is more of a convenience than a strong preference.
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Watching the Storm

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Here’s my favorite photo from Hurricane Gustav. My granddaughter wasn’t really watching the hurricane but the wind and rain continued for a while.

This shot was taken with my G9 in raw mode, ISO 400, max zoom, f4.8, 1/60 second. The small Flexizone frame was used to focus. My granddaughter is quite active and quick but was captivated by the scene and stayed at the door long enough for me to check exposure in Av mode, see that the histogram wasn’t right, shift to manual exposure and get a good histogram. One shot and she was gone!

Processing in ACR from the raw file, I decided to let the back of her head and dress go a bit dark. At ISO 400, noise begins to be noticeable with the G9, especially for enlargements, so I used Noiseware at about half strength to reduce the noise.

The final 8x10 print was cropped only slightly from the original capture. I like it.

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Gustav – Day Seven

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This morning in church, by a show of hands, roughly a third of the congregation was without electric power at their house. The newspaper report is that, by the end of the day, power will have been restored to half of Baton Rouge.

Some traffic signals are operating; others are not. People are driving very carefully.

This evening, my son noticed that our cable service, including Internet, had come back to life.

I took a few pictures, but not very many, during Gustav and will post some during the next few days. With no power and a heavy overcast sky, I used higher ISO than normal with my G9. Although many gripe about G9 noise at high ISO, it is actually very useable at ISO 400 and even 800 with a little post processing. My judgment was that available dim light and high ISO was more representative of the situation than if flash had been used.

We now resume our normal programming …
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Gustav – Day Six

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Electric power and air conditioning are still working fine. We take these conveniences for granted until they are no longer available.

In the general Baton Rouge area, the overall situation is considerably improved. More and more houses have electric power although many – perhaps even most -- are still without power. More gasoline stations are open and waiting lines are virtually non-existent.

Now we have Hurricane Ike to worry about. My wife and I decided to restock today in anticipation of Ike. We bought groceries and general supplies. I bought $85 worth of gasoline for the generator. $85! How times have changed! I was happy to get the gasoline.

Although many stores and businesses are closed, I did a bit of shopping. Wal-Mart, Sam’s, Lowes and Home Depot are open and doing a brisk business. All have generators. Roughly $800 for a 5500 watt generator – somewhat the same as my own. Interestingly, no stores have large gasoline cans. I saw several people buying a generator and a “bubble pack” of six two gallon gas cans.

The general operating procedure with a generator is to power a refrigerator, a small window unit air conditioner, several fans, a few lights and a radio. If you also have a freezer or two window air conditions then you alternate between those units. Gasoline consumption is roughly six to eight gallons per 24 hours of operation.

I finished the day by doing more yard work but some of this was routine. I’m ready for routine.
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