Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-09-2011, 08:00 PM   #1
New Member




Join Date: Sep 2010
Location: Nebraska
Posts: 4
zoom comparison question (SLR vs P&S)

I have a canon sx20is currently and am planning on upgrading to a KR sometime soon. I'm wondering how zooms compare with P&S to SLR's...

If I take a picture at a certain distance with my canon set at 20x, what would be an equivalent zoom with a KR?

The canon says it is 28 to 560mm equivalent. does that mean I would need a 560 zoom to be equal in power??

thanks.

12-09-2011, 08:07 PM   #2
Pentaxian
JinDesu's Avatar

Join Date: Jun 2011
Location: New York City
Photos: Gallery
Posts: 5,624
Essentially yes - if you want a 12MP shot at full 20x zoom on the canon, the k-r would need a 560mm lens or equivalent.

Although if say you wanted to put that picture on FB, you could probably crop the k-r to about 1/3rd the size and use a sharp 200mm lens and it'd end up the better with the k-r picture probably (FB picture resolution is 720x468)
12-09-2011, 08:15 PM   #3
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
Welcome aboard!!


The Sx20 has very small sensor like all the P&S cameras. The small sensor does come with some drawbacks, such as poor low light/high ISO pictures - the picture gets grainy and noisy, the speed of focussing and getting it to click is not good compared to a DSLR, and bokeh - you cannot get the small sensor to produce blurred background effects easily like you can with a DSLR. You also get the ability to use off-camera flashes for more natural looks and fill effects that P&S flashes just can't do. The DSLR has one major change to solve these issues - it uses a much larger sensor. However, this means that a 20x lens would be huge, heavy and expensive. You also get other benefits, like being able to change the lens to suit what you are shooting, being able to have an ultrawide that can take a photo of from your feet to infinity, of having better high ISO pics, of being able to shoot click, click, click fast and so on. Most of us have a P&S that we use too. I take my Panasonic with me nearly everywhere because of its size. However, when I am shooting something more important, planned, or just for my own enjoyment I pull out my dSLR.
12-09-2011, 09:22 PM   #4
Site Supporter
cali92rs's Avatar

Join Date: May 2011
Location: Long Beach, CA
Posts: 3,203
QuoteOriginally posted by JinDesu Quote
Essentially yes - if you want a 12MP shot at full 20x zoom on the canon, the k-r would need a 560mm lens or equivalent.

Although if say you wanted to put that picture on FB, you could probably crop the k-r to about 1/3rd the size and use a sharp 200mm lens and it'd end up the better with the k-r picture probably (FB picture resolution is 720x468)
Are you sure? I believe when Canon or any camera manufacturer uses the term 'equivalent' they refer to a Full Frame sensor. Therefore, on the K-r, it would require an 18-373mm lens to obtain the same field of view. Which doesn't exist of course.

12-09-2011, 09:34 PM   #5
Veteran Member
Frogfish's Avatar

Join Date: Dec 2009
Location: Shanghai
Posts: 4,490
QuoteOriginally posted by cali92rs Quote
Are you sure? I believe when Canon or any camera manufacturer uses the term 'equivalent' they refer to a Full Frame sensor. Therefore, on the K-r, it would require an 18-373mm lens to obtain the same field of view. Which doesn't exist of course.
Yes exactly, the Kr APS-C sensor has a crop factor of 1.5 so 373mm is the equivalent of the Canon P&S. However since the quality is so much better cropping a shot from a much shorter focal length lens will get you the same image size of the Canon but at far better IQ.

There is far far more to owning a DSLR than just FL though and you will be blown away by the increase in IQ, other advantages of a DSLR and also the leeway it gives you to manipulate the photo in software. Exciting times ahead for you .. the Kr is an excellent camera !
12-09-2011, 09:34 PM   #6
Pentaxian
JinDesu's Avatar

Join Date: Jun 2011
Location: New York City
Photos: Gallery
Posts: 5,624
QuoteOriginally posted by cali92rs Quote
Are you sure? I believe when Canon or any camera manufacturer uses the term 'equivalent' they refer to a Full Frame sensor. Therefore, on the K-r, it would require an 18-373mm lens to obtain the same field of view. Which doesn't exist of course.
Oh that is right, I forgot we have aps-c. Then yeah, 373mm would be the equivalent lens requirement on a K-r.
12-09-2011, 11:03 PM   #7
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
QuoteOriginally posted by cali92rs Quote
Therefore, on the K-r, it would require an 18-373mm lens to obtain the same field of view. Which doesn't exist of course.
Actually that would be 21-373 but why quibble?

The closest candidate would be the old DA18-250 or its Tamron twin -- and doesn't Sigma have a not-well-regarded 18-270 now?
12-09-2011, 11:18 PM   #8
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Oregon
Photos: Gallery | Albums
Posts: 10,289
QuoteOriginally posted by RioRico Quote
doesn't Sigma have a not-well-regarded 18-270 now?
I think that is Tamron, and as far as I know not in Pentax mount as yet. Listed as available for Canikon & Sony. But yes, well regarded I hope they make a Pentax mount.

12-10-2011, 12:24 AM   #9
Site Supporter
cali92rs's Avatar

Join Date: May 2011
Location: Long Beach, CA
Posts: 3,203
QuoteOriginally posted by RioRico Quote
Actually that would be 21-373 but why quibble?

The closest candidate would be the old DA18-250 or its Tamron twin -- and doesn't Sigma have a not-well-regarded 18-270 now?
It's Friday and my brain is off this weekend
12-10-2011, 12:51 AM   #10
hcc
Pentaxian
hcc's Avatar

Join Date: Nov 2009
Location: Brisbane, Australia
Photos: Gallery | Albums
Posts: 3,482
The closest option is the Tamron/Pentax DA18-250mm and the Sigma 18-250mm OS HSM. The former is no longer manufatured but it can be easily purchased 2nd hand from the PF marketplace, and reliable 2nd hand sellers like Keh.com and Adorama. The latter (Sigma) is more expensive, can be purchased new, but the lens OS is not compatible with the camera IS (and must be swiched off).

I have the DA18-250mm and I compared it with my older Panasonci FZ20 equipped with a 12x zoom. The DA18-250mm + K-7 gives me better IQ by far IMHO, and the images can be cropped 100% and still give a better IQ than the FZ20 at 12x.

Hope that the comment may help,
12-10-2011, 07:24 AM   #11
New Member




Join Date: Sep 2010
Location: Nebraska
Posts: 4
Original Poster
thanks for the replies - answers my question exactly!
I kind of figured that it would take a much higher zoom to be exactly the same picture without cropping; but could have a much less zoom and crop down to the same size with a lower zoom.
I'm looking forward to this as well as many of the other plusses pointed out by some of you!
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, canon, equivalent, kr, pentax help, photography
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
All Purpose Zoom Comparison wsteffey Troubleshooting and Beginner Help 16 08-31-2011 10:31 AM
50mm IQ comparison question raymeedc Pentax SLR Lens Discussion 4 05-09-2011 07:01 AM
Prime & Zoom Lens Question LadyRo Pentax SLR Lens Discussion 9 06-01-2010 06:34 PM



All times are GMT -7. The time now is 04:21 AM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top