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03-12-2011, 11:34 AM   #1
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Low Light question

I'm curious. I know my K7 isn't the best in low light situations. If I had something I was shooting in low light, would I be better to use my K7 or my *istD, or are they about equal in low light?

03-12-2011, 02:14 PM   #2
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If you can keep the ISO low and used timed exposures (shoot Av), the K7 will do fine. If you need to raise the ISO, you can probably go to about 1200 and still be able to clean it up with processing software. I've never used an istD so can't answer the which is better question.

03-12-2011, 03:09 PM   #3
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Caveat I do not have either the K-7 or *st-D.

But low/available light photography is of particular interest to me -
I have been posting low light shots regularly to a thread: Kx in Use ( 1 2 3 ... Last Page)

I base some of my take on the test results from various sources like Imaging-Resource.com, dcResource.com, and dpReview.com.

I do have the K100D which I think may use the same sensor as the *st-D.

First the obvious - K-7 is 14.6Mp vs. 6Mp of the *st-D - this means that the K-7 has a lot more Mp to play with for pp noise reduction (NR) - using any of the well known NR software like Topaz deNoise, NoiseWare, NoiseNinja etc - some really good high ISO results have been shown from the K-7.

Obviously RAW would give an additional step in IQ - but I believe that any of those NR programs will work fine on JPGs too.

A worthwhile note is that NoiseWare has a Free Community edition.

Back to the comparison - the *ist-D did very well in reviews back when it was new:

getting comments like:
Imaging-Resource.com -
" Night Shots: Excellent low-light performance, with good color at even the darkest light levels. Excellent low-light focusing ability as well. The *ist D offers full manual exposure control, with adjustable ISO and a maximum shutter time of 30 seconds. Thus, the camera can capture bright images in very low lighting. The *ist D produced clear, bright, usable images down to the 1/16 foot-candle (0.67 lux) limit of my test, with good color at all five ISO settings. However, some slight color shifts occurred depending on the brightness level. The *ist D's optional Noise Reduction system has a fairly subtle effect on noise levels, but the noise wasn't as bad as I imagined it would be, even at the ISO 3,200 setting. Even though it has no autofocus-assist light, the *ist D can achieve focus lock at very low light levels. While the AF speed slowed significantly at low light levels, I found that my test unit of the *ist D could routinely focus at light levels as low as 1/4 foot-candle, and sometimes focus as dark as 1/8 foot-candle, without using its focus-assist illuminator, and with a lens with a maximum aperture of f/4.0. (This is a pretty impressive performance, 1/4 foot-candle corresponds to an exposure time of 8 seconds at f/2.8 and ISO 100.) "

dcResource.com -
" ... noise levels are extraordinarily low, even at ISO 1600.
... and noise (it's non-existent) ...
Low noise all the way to ISO 1600 "

I think (like the K100D) up to ISO1600 one could shoot almost with impunity - it is only ISO3200 that might be questionable.

However I moved from the K100D to the K-x because of the extraordinary HighISO performance of the K-x - which still holds its own today even in the company of the newer K-r, and possibly K-5.

I use the K-x because I use only the two kit zooms 18-55 Mk1 (max ap f/3.5) and 50-200 zoom max ap f/4) - but I can shoot in a dark jazz club without any qualms at up to ISO5000 and it's so dark - many areas are below both the AF and metering limits of the K-x specs (with those 2 zooms)

I see you have some fast primes -
I had the A50 f/2 for a short while - and I did not like its performance at apertures wider than about f/3.5-f/4 - so that did not show much advantage for me in the dark and I lose AF.....

But I believe the 55 f/1.8 is supposed to be really good -
so shooting at ISO1600 or below would probably be very acceptable to me, of course YMMV.

The same would apply to the K-7 shoot ISO1600 which is kind of acceptable (to me) to begin with - run the shots through NR - and I think you'll be fine......

Please take a look at my thread:

Kx in Use ( 1 2 3 ... Last Page)

I know it's the K-x - and it may seem like a joke to shoot low available light with the two kit zooms -
my latest foray to the dark jazz club was only two nights ago on Thursday Mar/10 - in Post #153 (link).
My first post about that venue was Dec/26/2009 in Post #5 (link)

I have since then posted a total of over 500 photos on my Picasa photo web page (Pure Soundz 495 photos, and Pure Soundz pt.2 30 photos) from that venue almost all low light and on the K-x and a lot has evolved in my technique over the year and nearly half.....

My short experience on the A50 f/2 prime is in Post #146
and my review with comparison samples
https://www.pentaxforums.com/lensreviews/SMC-Pentax-A-50mm-F2-Lens.html#review3426

I much prefer to shoot with the 2 humble kit zooms where I do not have too much concern about very shallow DoF - and to me on the K-x give me more than acceptable results - of course as always YMMV.

On the K-x, 18-55Mk1 @ 55mm and wide-open f/5.6

ISO5000, f/5.6, 1/6, 55mm (18-55 zoom)

18-55Mk1 @ 40mm - Wide-Open f/4.5

ISO5000, f/4.5, 1/25, 40mm (18-55)

Before anyone complains these last 2 are noisy -
please remember these were both at ISO5000
in dark enough conditions that they were close to the metering and focusing limits of the K-x.

Last edited by UnknownVT; 03-12-2011 at 04:04 PM.
03-12-2011, 07:53 PM   #4
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UnknownVT, very nice pictures.
Were these all shot with manual focus? My K-x loses the ability to focus very quickly in low light.

03-12-2011, 09:28 PM   #5
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QuoteOriginally posted by eccs19 Quote
I'm curious. I know my K7 isn't the best in low light situations. If I had something I was shooting in low light, would I be better to use my K7 or my *istD, or are they about equal in low light?
If you have both cameras, why not do a quick test to find the answer and let us know what it is.
03-13-2011, 12:56 AM   #6
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QuoteOriginally posted by 7samurai Quote
UnknownVT, very nice pictures.
Were these all shot with manual focus? My K-x loses the ability to focus very quickly in low light.
Thank you.

Nope, it's AF with the 18-55 mk1 kit zoom -
no problems with AF on those shots -
it's the dark recesses/corners that may show some problem
since they may be actually below the spec of the K-x AF - like:


where I have to make sure I pick a high contrast point to focus on - in this case the trumpet bell - even though it is not ideal nor the most correct - unfortunately at such low light levels it would not be possible to focus on the eye - so I use the nearest high contrast target and allow the DoF to do its work........

Scene doesn't seem that dark? here's the overall scene -

it's off stage and out of frame of this shot to the right - in the corner of the room...... not quite a coal cellar......
03-13-2011, 03:46 AM   #7
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I shot with a k100 and it it can do iso 3200, although it doesn't look the best. The thing you have to remember is that you will have to resize down the K7 photos in order to compare them to a 6 megapixel image. If done correctly, this should reduce noise. The other thing is to invest in a good program like Topaz Denoise. With this, you can easily shoot to iso 3200 with the K7 and have clean images.

Bottom line, even if the high iso abilities are roughly equivalent on the two cameras, there are many other features on the K7 that will help you get better shots in low light situations and I would probably use that.
03-13-2011, 06:45 AM   #8
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QuoteOriginally posted by eccs19 Quote
I'm curious. I know my K7 isn't the best in low light situations. If I had something I was shooting in low light, would I be better to use my K7 or my *istD, or are they about equal in low light?
Eccs19,

There has been *a lot* of discussion on the K-7 noise levels at higher ISO.
Also, there has been *a lot* of good examples of K-7 low light pictures.

The K-7 is 3 generations younger than a *istD.
It has much more pixels and a much better AF system.
The last works a lot better in low light situations than your *istD AF does.

What you should learn, is how to control your K-7 noise.
When you limit the ISO to 1600 - 2000, and make sure not to underexpose, you'll be fine.
Next, invest in a proper post processing tool. The latest Lightroom version 3 has a great noise reduction function.

You can find several posts with good K-7 low light examples.

Here are a few:

ISO 1600:





ISO 2000:



ISO 6400 (with LR 3.3 noise reduction):



Have fun

- Bert

03-13-2011, 09:43 AM   #9
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QuoteOriginally posted by eccs19 Quote
I'm curious. I know my K7 isn't the best in low light situations. If I had something I was shooting in low light, would I be better to use my K7 or my *istD, or are they about equal in low light?
Do you mean low light, or do you really mean low light at a high ISO. There is a big difference. The K7 is great in low light. It's not so great in low light at a high ISO.
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