Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-09-2010, 04:06 PM   #1
Inactive Account




Join Date: Feb 2010
Location: UK
Posts: 57
Am I expecting too much out of an old lens?

So I've just started playing with primes, and have a auto Chinon 50mm f1.7 MF lens. I'm really enjoying using it, and it is sharper than my Sigma 18-200mm zoom, but I'm left feeling like the images still aren't crisp enough.

I'm attaching a few of the images that I've taken, with a very very minor amount of PP in Lightroom (they were in raw so I had to export them somehow). I think the aperture was fairly reasonable in the daytime shots (above f2.0). I exported with 'output sharpening for screen' and it really makes a noticeable difference from what I'm seeing in Lightroom. What I see in lightroom looks a lot more blurry than the exported images.

So, am I expecting too much out of an old lens? If you normally get a lot more out of older lenses, should I maybe go shopping for a SMC Pentax-M f1.4? On the other hand, if I'm expecting too much, would I be happier saving up for a new DA prime?

I've just seen some breath-taking detail from some photo's and am wondering how one goes about getting that. It's also possible I'm not doing something else obvious to make the pictures look more 'professional', but I'm just not sure what that would be.

Attached Images
View Picture EXIF
PENTAX K10D  Photo 
View Picture EXIF
PENTAX K10D  Photo 
View Picture EXIF
PENTAX K10D  Photo 
View Picture EXIF
PENTAX K10D  Photo 
02-09-2010, 04:25 PM   #2
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
You can't expect great sharpness over a thick DOF with the lens wide open. Your Chinon is MUCH faster than your Sigma, with pretty thin DOF when wider than f/2.8. You need to stop down (the old fotog's rule: f/8 and be there). Shooting wide, you need to be very aware of just how much of your subject(s) is/are within the DOF. The lens's distance/aperture markings should guide you to the right hyperfocal distance.
02-09-2010, 04:29 PM   #3
Inactive Account




Join Date: Feb 2010
Location: UK
Posts: 57
Original Poster
Wow, f/8 seems pretty high to use - I guess use that when the light is available then. Will try some shots tomorrow and see how things go.
02-09-2010, 04:45 PM   #4
Site Supporter
davidreilly3207's Avatar

Join Date: Sep 2009
Location: South Jersey
Photos: Gallery | Albums
Posts: 587
Also, be aware that when viewing photos in Lightroom, you need to be in 1:1 view to see the results of any sharpening or noise reduction.

02-09-2010, 05:21 PM   #5
Veteran Member




Join Date: Jun 2009
Location: on the wall
Photos: Gallery
Posts: 715
I found that the preset Lightroom (RAW) sharpness levels don't match my perception of my images' sharpness. Individual adjustments are necessary.

This may seem tedious, but, you wanted this type of control, right?

The main problem is compensating thru oversharpening. That is easy to spot.
02-09-2010, 06:42 PM   #6
Veteran Member
rparmar's Avatar

Join Date: Jan 2008
Photos: Gallery
Posts: 8,783
Shot 2 has very shallow DOF, so very little will be in focus by definition. Shot 1, being at night, I presume was wide open as well, or close to it. As RioRico said, this is going to be very difficult to focus. Not impossible, but a lot of practice is called for.

While you may not afford the luxury of f/8, try f/2.8. This will also mean you are operating in a sharper regime of the lens as well.

As for PP, all RAW images need sharpening. learning the right way to do this and what settings suit the image is a journey, not something for which there is any one right answer.

I would say that in general one needs to sharpen three times. First, to remove the misty look of the RAW, gaining clarity. Second to accentuate details. Third, when printing or targeting a destination device. Each pass should be subtle. I think that everyone over-sharpens before they learn better. I know I did.
02-09-2010, 07:29 PM   #7
Loyal Site Supporter
imtheguy's Avatar

Join Date: Mar 2009
Location: Virginia Beach
Photos: Gallery | Albums
Posts: 2,950
I can't judge the focus in relation to your settings except for shot #2 which is appears to be in the neighborhood of f/2. I took the liberty of adjusting the WB then sharpening the areas witin the thin dof and it came out very nice. At least as sharp as I would want to see it. Judging by that one shot I don't see anything wrong with the lens. At least not at that range and aperture. I use an A50mm f1.4 and my cat shots at f/1.4-2.4 are similar before PP. Outside I usually go to f/5.6.
02-09-2010, 08:18 PM   #8
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
I was being a bit glib. "F/8 and be there" is a rule for daytime "significant moment" shooting -- set the aperture to f/8, set the f/8 mark to infinity, and you have a fairly thick DOF, depending on the lens. For less stressful shooting, f/2.8-5.6 can be quite good. Like I said, look at the distance-aperture marks on the lens, and set your aperture and focus accordingly. Those marks are your DOF computer, a handy circular slide rule.

If you set your 50mm Chinon to f/4 and focus to 20 feet, your DOF should be 15-50 feet. At f/8 it's 10 feet to infinity, great for street shooting. But at f/2.8, focused to 8 feet, your DOF is just 7-9 feet, or 24 inches thick. And wide open at f/1.7, focused closest, you've got less than an inch of sharp DOF. There ain't no free lunch. For sharpness, stop down. For low-light or bokeh, open up, but expect softness. That's how the optics work.


Last edited by RioRico; 02-10-2010 at 06:57 AM.
02-10-2010, 07:58 AM   #9
Inactive Account




Join Date: Feb 2010
Location: UK
Posts: 57
Original Poster
Gotcha, thanks for the heads up lads. I guess I've got a bit of learning with lightroom to do / and will try a few more wide aperture shots.
02-10-2010, 08:57 AM   #10
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,400
if I consider shot 2 with the tip of the cat's nose in focus, there seems to be nothing wrong with sharpness.
as others have mentioned a 50mm lens at F1.7 has very little depth of field so you would expect a close up of a the cat to have varrying degrees of sharpness due to depth of field,.
another point to consider is that with shallow depth of field from the lens, and without a split image focusing aid, exact focus is difficult on a MF lens.
You may be suffering more from focus error than image quality
You also need to consider that the viewfinder of a DSLR has more DOF than yoou actually get, again making accurate focus difficult
02-10-2010, 09:13 AM   #11
Site Supporter
GeneV's Avatar

Join Date: Oct 2008
Location: Albuquerque NM
Photos: Albums
Posts: 9,775
The last shot appears to be outside in a good deal of sunlight. Just off the top of my head, at ISO 100 that shot would probably be well exposed in the neighborhood of F8 1/250. If you weren't using at least F8, then your shutter speed must have been very high.
02-11-2010, 07:10 PM   #12
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 27,479
QuoteOriginally posted by GeneV Quote
The last shot appears to be outside in a good deal of sunlight. Just off the top of my head, at ISO 100 that shot would probably be well exposed in the neighborhood of F8 1/250. If you weren't using at least F8, then your shutter speed must have been very high.
Exif says 1/2000s @ ISO 100...

Steve
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, images, lens, lightroom, lot, pentax help, photography
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Out Of Focus - Am I expecting too much? seachunk2 Troubleshooting and Beginner Help 28 03-02-2010 03:27 PM
Why so many expecting full frame form Pentax? ytterbium Pentax News and Rumors 136 08-31-2009 09:30 PM
I'm Expecting! magnum1 Welcomes and Introductions 4 10-10-2007 08:10 PM
Lemon or over-expecting? FA 20-35 clawhammer Pentax SLR Lens Discussion 19 09-22-2007 08:17 PM



All times are GMT -7. The time now is 10:39 AM. | See also: NikonForums.com, CanonForums.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