Go Back   Steve's Digicams Forums > Digicam Help > What Camera Should I Buy?

Reply
 
Thread Tools Search this Thread
Old Dec 18, 2006, 11:11 PM   #11
Senior Member
 
Corpsy's Avatar
 
Join Date: Dec 2005
Posts: 879
Default

Well, um, OK, a couple things.

Ken, you might want to knock the A100 down a notch. The 1600 ISO shot was underexposed (they provided another ISO 1600 image with levels adjusted as well). If you look at the ISO 800 EXIF you'll see that it's more in line with Group C.

Also, I compared the Alpha at ISO 800 to the K100d at 1600 and the K100d is far better, even without all the extra pixels. So I guess the Sony is once again off my short list and back on my shh... other list.

I noticed this thread is now green, which apparently means "important". Maybe we're going to see people start to expand on your exposure sensitivity guide Ken.
Corpsy is offline   Reply With Quote
Old Dec 20, 2006, 2:54 PM   #12
Senior Member
 
Join Date: Aug 2006
Posts: 822
Default

Quote:
Ken, you might want to knock the A100 down a notch. The 1600 ISO shot was underexposed (they provided another ISO 1600 image with levels adjusted as well). If you look at the ISO 800 EXIF you'll see that it's more in line with Group C.
True-that image was noticeably underexposed.

But, I'm really not at all confident in any of these groups at this point. I only looked at that one sample shot at the time I made that list. I was hoping that looking at more would help sort it out; but now that I've looked at a few more samples for each, some of them are all over the map.

For now, I'd guess the D70 is also probably back in the same group roughly as the other older models, and I still think there is a less sensitive group with some of the newer models, including the K100D, but I'm going to have to continue to check data from a couple of other places beforre I have any confidence in it.

kenbalbari is offline   Reply With Quote
Old Dec 22, 2006, 8:08 AM   #13
Senior Member
 
Join Date: Feb 2004
Posts: 105
Default

There is one other unmentioned relevant factor when comparing different camera sensitivities, and that's shutter speed and aperture innacuracies. Shutter speeds have fairly large steps between them, e.g. 1/10, 1/13, 1/15, 1/20, 1/25, 1/30, 1.40sec, and f-stops similarly f2.8, 3.2, 3.5, 4.0, 4.5 etc on my K100D, and we have no way of knowing how precisely these figures are actually achieved mechanically in camera. In other words I personally wouldn't put too much faith in calculations based on what the camera reports. I could be wrong of course.
SteveB is offline   Reply With Quote
Old Dec 23, 2006, 1:17 PM   #14
Senior Member
 
Join Date: Aug 2006
Posts: 822
Default

Quote:
There is one other unmentioned relevant factor when comparing different camera sensitivities, and that's shutter speed and aperture innacuracies. Shutter speeds have fairly large steps between them, e.g. 1/10, 1/13, 1/15, 1/20, 1/25, 1/30, 1.40sec, and f-stops similarly f2.8, 3.2, 3.5, 4.0, 4.5 etc on my K100D, and we have no way of knowing how precisely these figures are actually achieved mechanically in camera.
Good point. I'd actually like to see a reviewer set up regular test shots in controlled conditions with a moving subject. You could have controlled lighting, and then use something like an electric train as a subject to always have the same degree of motion every time.

kenbalbari is offline   Reply With Quote
Old Dec 23, 2006, 9:19 PM   #15
Senior Member
 
Corpsy's Avatar
 
Join Date: Dec 2005
Posts: 879
Default

I doubt there is much inaccuracy when it comes to shutter speed, particularly among SLR cameras. I could be wrong of course. You can find out if the speed is as reported by recording the sounds the camera makes when it snaps a picture and analyzing it in an audio editor.

As far as the aperture values, that's a function of the lens. While I would assume those would be pretty accurate as well, the actual amount of light that gets through the lens may also depend on the quality of the glass.

If there were significant variations in these values, like if a 1/120 shutter speed was actually 1/130, or f-stop 4 was more like 4.5, I think you'd see a lot of problems with cameras getting wonky metering results, since if a situation calls for 1/120 at f/4 and you actually get 1/130 at f 4.5, you'd get a noticeably dark exposure.

In any case, I would think that any variances in these cases would be negligible, since if you shoot the same scene with two different cameras using the same f-stop and ISO setting, it should give you a pretty fair comparison of how they would perform relative to each other in similar circumstances. I find it extremely doubtful that if two cameras metered exactly the same in one lighting condition and got the exact same exposure using the same f-stop, shutter speed and ISO, that they would somehow get vastly different results in a darker or brighter environment.
Corpsy is offline   Reply With Quote
Old Jan 21, 2007, 10:21 AM   #16
Senior Member
 
Join Date: Sep 2005
Posts: 734
Default

Here is the XTI
Attached Images
 
coldshot is offline   Reply With Quote
Old Feb 1, 2007, 3:39 PM   #17
Member
 
JinE's Avatar
 
Join Date: Apr 2004
Posts: 99
Default

mtclimber wrote:
Quote:
Corpsy-


But please keep in mind that the differences between the Canon XT, XTi, The Nikon D-40, D-50 and even the D-80, along with the Pentax K100D and K10D are verysmall. In fact, we urge all camera fans who are interested in DSLR cameras to handle and use every one of the consumer DSLR cameras. They are ALL GOOD.


MT/Sarah


I agree with this poster that the IQ between the BODIES of the various camera is quite small. The IQ between the manufacturers doesn't become apparent until you start considering the lens and accessory availability for the body you are looking for. Each manufacturer covers the focal ranges differently with their offerings of lenses, I would find the 2-3 bodies you like the most and look at the lens offerings/quality/availability/price that you can get for you body in the focal lengths and speeds you want.
JinE is offline   Reply With Quote
Old Feb 4, 2007, 6:40 PM   #18
Senior Member
 
Redsquare's Avatar
 
Join Date: Nov 2006
Posts: 228
Default

What is that big bulky bit on the bottom, I've also seen the xt with that on too but it doesnt come with the kit. Whatever it is, Can it be bought seprately?
Redsquare is offline   Reply With Quote
Old Feb 4, 2007, 9:01 PM   #19
Senior Member
 
Join Date: Sep 2005
Posts: 734
Default

All current Canon DSLR have the option to hook up a battery grip. The XT and XTI share the same grip with two cartridges, one for 2 dedicated lithium batteries, one for 6 AA for longer shooting capability. The grip doesn't come with the camera & kit lens, it's optional. The Canon grip is around $200, the aftermarket is somewhere around $100. Another benefit to have a battery grip is when you use any zoom lens longer than the kit lens, you increase the weight, the grip helps to balance the camera/zoom level to your body, otherwise your camera tilts down, expose the back of the camera up in the air, in bright daylightthe LCD could face the sun, most people feel uncomfortable walking around with the camera upside down. It's a good option to look for when consider a new DSLR.

You don't want to stand next to the guy his camera is up yours is down, or worse next to an attractive lady. It happened to me, I rush out and buy the grip real quick and willingly, happily paida highprice.:-)
coldshot is offline   Reply With Quote
Old Feb 5, 2007, 11:49 AM   #20
Senior Member
 
Redsquare's Avatar
 
Join Date: Nov 2006
Posts: 228
Default

Aghh right thats what it is, Can you get these for the Nikon D40?
Redsquare is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 3:39 PM.