Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-19-2008, 02:43 AM   #16
Syb
Site Supporter
Syb's Avatar

Join Date: Aug 2007
Location: Near Utrecht, Netherlands
Photos: Gallery
Posts: 1,224
This is very good news. At least, it is to me. Not only can I trust the distance scales on my lenses again (didn't know that yet), but I get more quality than I thought out of the glass I had.

What I like about the APS-sensor is the longer focal length (50mm will work like a 75). But the second thing I like is a small depth of field. That is what makes me buy expensive tele glass: the fact that it is possible to select a short distance range to be in focus, even if that range is far from the camera.

Now in this tread I learn that F/8 will work like a F/5.6 would work on film. But this means actually that on a APS-sensor, a

50mm lens @ 1.4 (we all know which lens I am referring to)

will show you what a

75mm lens @1.2
would do on film.



Now talking about the creative options provided by digital camera, this is most certainly one of them. For me it is a pretty clear second reason to -NOT- want a Full Frame sensor. The first is that I like the x1.5 crop a lot. Makes my tele lenses much more tele than they were before.

The only thing I would like now, is a sensor that would catch more dynamic range. For that is the real disadvantage of Digital versus film.

12-19-2008, 09:41 AM   #17
Site Supporter




Join Date: Jan 2007
Location: Upstate New York, US
Photos: Albums
Posts: 223
QuoteOriginally posted by Syb Quote
This is very good news. At least, it is to me. Not only can I trust the distance scales on my lenses again (didn't know that yet), but I get more quality than I thought out of the glass I had.

What I like about the APS-sensor is the longer focal length (50mm will work like a 75). But the second thing I like is a small depth of field. That is what makes me buy expensive tele glass: the fact that it is possible to select a short distance range to be in focus, even if that range is far from the camera.

Now in this tread I learn that F/8 will work like a F/5.6 would work on film. But this means actually that on a APS-sensor, a

50mm lens @ 1.4 (we all know which lens I am referring to)

will show you what a

75mm lens @1.2
would do on film.



Now talking about the creative options provided by digital camera, this is most certainly one of them. For me it is a pretty clear second reason to -NOT- want a Full Frame sensor. The first is that I like the x1.5 crop a lot. Makes my tele lenses much more tele than they were before.

The only thing I would like now, is a sensor that would catch more dynamic range. For that is the real disadvantage of Digital versus film.
I'm afraid it doesn't work this way. The amount of depth of field gained by using a 50mm lens over a 75mm lens more than offsets the amount lost by going from a 35mm sensor or film to an APS-C sensor. So for a given angle of view you get more depth of field from smaller films/sensors than from large ones.

If you ever shoot medium or large format, you will notice that your depth of field always seems thinner than you would expect coming from 35mm cameras, and this is because you are always shooting with longer lenses to get the same field of view.

Edit: Just wanted to add that the comparison is more like a 50mm f/1.4 lens on APS-C is similar to a 75mm f/2.2 lens on 35mm at 1.5 meters (the equivalency varies with subject distance).

Last edited by CFWhitman; 12-19-2008 at 10:03 AM.
12-19-2008, 11:56 AM   #18
Veteran Member
Sean Nelson's Avatar

Join Date: Sep 2008
Location: Vancouver BC Canada
Posts: 353
QuoteOriginally posted by Syb Quote
Now in this tread I learn that F/8 will work like a F/5.6 would work on film. But this means actually that on a APS-sensor, a

50mm lens @ 1.4 (we all know which lens I am referring to)

will show you what a

75mm lens @1.2
would do on film.
You've got it backwards!!!

The reason why you use the one-stop-wider markings on the DOF scale for a film lens on an APS-C camera is because you're using the SAME LENS.
The SAME LENS has LESS depth of field when used on a smaller sensor camera.

You're comparing lenses with the SAME FIELD OF VIEW.
SAME FIELD OF VIEW has MORE depth of field on a smaller sensor camera.
12-19-2008, 12:10 PM   #19
Syb
Site Supporter
Syb's Avatar

Join Date: Aug 2007
Location: Near Utrecht, Netherlands
Photos: Gallery
Posts: 1,224
QuoteOriginally posted by CFWhitman Quote
If you ever shoot medium or large format, you will notice that your depth of field always seems thinner than you would expect coming from 35mm cameras, and this is because you are always shooting with longer lenses to get the same field of view.

Edit: Just wanted to add that the comparison is more like a 50mm f/1.4 lens on APS-C is similar to a 75mm f/2.2 lens on 35mm at 1.5 meters (the equivalency varies with subject distance).
Thank you for putting me back with my feet on the ground. There are many variables in this equation, and I guess I am only starting to see the brink...



12-19-2008, 12:12 PM   #20
Syb
Site Supporter
Syb's Avatar

Join Date: Aug 2007
Location: Near Utrecht, Netherlands
Photos: Gallery
Posts: 1,224
QuoteOriginally posted by Sean Nelson Quote
You've got it backwards!!!

SAME FIELD OF VIEW has MORE depth of field on a smaller sensor camera.
Yeah. That makes sense again. Oh dear.
I find myself growing into a fan of Full Frame....

....

AAAAAAAAAAAAAAAAAAArgh!
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!
k-mount, lens, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
SMC-A 70-210 lens markings? enoxatnep Pentax SLR Lens Discussion 6 12-22-2009 04:02 AM
Manual lens markings? emr Pentax SLR Lens Discussion 3 07-05-2009 07:39 PM
Pentax 18-250mm Vs. Tamron 70-300mm, focal length markings are not the same aweir Pentax SLR Lens Discussion 1 04-04-2009 09:19 PM
Pentax-M 28mm F3.5 scale markings wiseman Pentax SLR Lens Discussion 11 03-03-2009 01:43 AM
Close-up lens markings gamgee Pentax SLR Lens Discussion 2 06-12-2008 06:28 AM



All times are GMT -7. The time now is 02:45 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