Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Sony Alpha dSLR / Konica Minolta dSLR, Sony SLT

Reply
 
Thread Tools Search this Thread
Old Oct 14, 2005, 6:23 AM   #1
Junior Member
 
Join Date: Oct 2005
Posts: 2
Default

hi,

I am reading all I can before I buy a new cam. So I was looking at that picture, and compared it to the the same view taken with a Nikon D50 and D70. The KM one seems bad. Look for exemple in the corner up right. Is the kit lens so inferior ?

Thanks for information.

Carbec
Carbec is offline   Reply With Quote
Sponsored Links
Old Oct 14, 2005, 7:34 AM   #2
Junior Member
 
Join Date: Aug 2005
Posts: 8
Default

That shot was at 35mm and f13.

People who have this lens camera combo know the trick...keep your fstop as close to f8 (or what we have been calling the sweet spot) as possable From f11 on, the pictures get soft. F22 and real soft! But if you were to take that same shot at f8, it would be tack sharp! Easily the same as the Nikon.
Cleanmaxx Brian is offline   Reply With Quote
Old Oct 14, 2005, 7:46 AM   #3
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

Take an editor and do 100% crops of the images.

If you look closely, these photos were taken from different perspectives.

Some parts of the image are taking up a greater percentage of the frame in the D50 photo of the building. Compare the size of the chimney top as an example. Notice how it's larger in the D50 image, allowing more pixels to represent it?

The photo with the Nikon was taken at a slightly longer focal length, and the distance/viewing angle for thescene was a little different, too.

Your distance to subject using different focal lengths will cause a difference in perspective (causing the image to look more or less compressed as you get further away from your focus point, depending on your distance).

Also, there was a big difference in lighting. Note how much brighter exposed the foilage is in the upper right in the Nikon images. You had more light hitting the foilage in the D50 image.

This combined with the Nikon'smore aggresive sharpening in camera is causing more of the foilage highilghts to show up (since sharpening algorithms are increasing contrastat edges which will show up more with the better lighting), giving more of an illusion of sharpness there (you'll see the same illusion if you brighten the 5D images and sharpen them).

Look at the darker areas of the D50 photo (foilage in shadows in upper right), and you'll see a soft look there, too (because the sharpening algorithms couldn't see the highlights to find contrast differences to sharpen the edges). There was a big difference in lighting for these photos.

Shutter speeds were also about twice as fast with the D50, reducing any potential blur caused by wind (something that's common taking photos of fine foilage).

Basically, you're comparing apples to oranges. There is far too much difference between these photos to tell much about optical differences. Unfortunately, it's just not possible to take photos at the same time, using the same settingswith allcameras reviewed. ;-)

Although if lighting, focal length, perspective, exposure and image processing would have been the same (and they weren't), I would have noted that the KM lens has much better color and contrast compared to the others, avoiding the washed out look you sometimes getshooting in brighter conditions with lenses that don't have optics and coatings designed to reduceflare as well.

But, since there were so many differences in the conditions and camera settings, that would not be fair to the other cameras.

JimC is offline   Reply With Quote
Old Oct 14, 2005, 8:45 AM   #4
Junior Member
 
Join Date: Oct 2005
Posts: 2
Default

Hi,

Thanks for the very detailed answer. A lot to read ! Its very hard to compare 2 cams then. I am still debating between Nikon D50 (with sigma 18-50/2.8 ; Minolta 5D (witk KM 18-70; not enough money to buy the sigma); and Nikon D70 (with Nikon 18-70). They have each advantages.

Friendly,

Carbec
Carbec is offline   Reply With Quote
Old Oct 14, 2005, 11:05 AM   #5
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

The Sigma seems to be an interesting lens in this niche, offering reasonable performance in a lens that's not as big as you'd expect (since it's designed specifically for a Digital Camera with a sensor smaller than 35mm film).

It's still a bit largerand heavier than something like the kit lenses you'll see from these camera manufacturers. But, that's a tradeoff for the brighter lens.

The KM lens isn't as bright as most (dropping off tof/5.6 as you increase focal length). But, from what I've seen of it so far, it's pretty good for the money, and has decent flare resistance, contrast and color. Now, if they could only give that much focal range in an f/2.8 lens with the same size, cost and weight.... (don't we wish). :-)

There are always tradeoffs when shopping for lenses.

I wouldn't overlook the used market either, and there is nothing that says you have to buy all of your lenses at once.




JimC 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 11:42 PM.