Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-06-2010, 09:26 PM   #1
Senior Member




Join Date: Oct 2009
Location: Florida
Photos: Albums
Posts: 231
Sharpness...

I have purchased a bunch of used and new lenses for my K7. Lots of Takumar's, Sigmas and Pentax zooms and primes. I just don't think any of them are very sharp. I started another thread on this, and have been unable to follow up with that one. To those who tried to help, thanks, and I will still try to upload comparison shots, but my question is, if you wanted a general purpose zoom, one for portraits and family type photo's, what would you get?

For simplicity, leave price out of the equation and list the 5 sharpest lenses in order (sharpest first) you would purchase. Cost will be a factor for me, but I really want to be happy with my camera, and I just don't get the pictures a lot of you get. I hope it's just the lenses, and I'm thinking if I pick up a 50-135 (or something else) and see a significant improvement in sharpness, (without a loss in other things like sat, contrast, etc) I would feel better.

Thank you...

04-06-2010, 10:31 PM   #2
Site Supporter
ovim's Avatar

Join Date: Sep 2008
Location: Tre, Finland
Photos: Gallery
Posts: 1,227
I looked up your previous thread and noticed you've strived for f8 with Takumars and other manual lenses. I don't think you'll get any noticeably sharper images with any lens as at f8 almost any lens should pretty sharp. Looking forward for some sample images.
04-07-2010, 02:26 AM   #3
Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 703
Hi

You have bought "Lots of Takumar's, Sigmas and Pentax zooms and primes" and cannot get sharp images with any of them.

Well without knowing what the lenses actually are, or seeing some examples i cannot be sure that my advice is going to be correct, but here goes anyway.

I suggest it it is more likely to be your technique that is at fault, or failing that, a problem with the camera. It is unlikely that all of your lenses are faulty ?

Did you get the kit 18-55 lens with your K7 ? When stopped down to f5.6-f8 it will be sharp. Please post some pictures so that we can assess properly. But I think it likely you will be wasting money buying new lenses trying to achieve sharpness when the fault lies elsewhere.

Peter
04-07-2010, 05:16 AM   #4
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
There's an old ROT (rule of thumb) that the best shutter speed for a lens is the reciprocal of the focal length (1/FL). In THE CAMERA, Ansel Adams writes of using a 50mm lens on a handheld 35mm film camera, where the ROT would indicate a shutter of 1/50 sec. But Ansel didn't get a sharp image until he shot at 1/250 sec. That's 2.3 EV faster.

If we estimate SR giving a 2-stop advantage on a dSLR, the new ROT would be to shoot at 1/FL, rounded to the next fastest speed. (Forget crap.factor; here, a lens is a lens, and its FL is its FL.) So a 55mm lens should be shot NO SLOWER than 1/60 sec, and 1/90 would be better. A 28mm lens -- 1/30 or 1/45 sec. Et cetera.

To actually find how sharp your lenses are: 1) Use a tripod, and shutter delay, and a remote. 2) Shoot RAW, and set all the JPEG parameters to zero/default. 3) Focus very very carefully; even with deep DOF, the central focus point will be sharpest.

A couple other tips for handheld shooting: In your menu, set Using Aperture Ring to Permitted; set Catch-In-Focus to On; set Program Line to Shutter Priority. Shoot at the highest shutter speed possible. Don't hold the camera to your face with your elbows sticking out -- keep your arms braced against your body, the camera firmly supported. Lean against a tree or wall or anything solid. Exhale, and press the shutter when you start to inhale. Don't shoot after drinking alcohol, caffeine, or milk (lactic acid affects visual acuity too). Practice the Zen of photography. Ommmmm....

04-07-2010, 05:28 AM   #5
Pentaxian
bdery's Avatar

Join Date: Mar 2008
Location: Quebec city, Canada
Photos: Gallery
Posts: 5,657
I agree with the others' comments. If you have a lot of lenses, and cannot get sharp images with any, work on your technique first.

That being said, you are asking me to list my dream kit, so to speak... I will oblige...

1-FA 50 f2.8 macro (I own it). Sharpest I've ever seen
2-F or FA 50 f1,7 (I own the F). Almost as sharp as the macro, great for low light
3-50-135 (I dream of it). I hear it's amazing
4-FA 31 limited (not interested). Supposed to be ludicrous too
5-DA 21 (on its way by mail). Supposed to be brutally sharp, among other things.

I must stress, now, that sharpness isn't everything. Not at all. My only currently accepted picture in the Pentax Photo Gallery was shot with a (very good) Sigma 17-70, and it's a "macro" shot. I shot the same composition with a different subject (a flower) with the FA 50 macro and the picture is not as good.

Photography is about light, then composition, then tools and technique.
04-07-2010, 05:56 AM   #6
Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 703
I would just add that I think it better if you start by shooting jpegs to test your lenses. Raw files are naturally unsharp and if you are not proficient in raw conversion, they won't necessarily help you.
04-07-2010, 05:57 AM   #7
Senior Member




Join Date: Oct 2009
Location: Florida
Photos: Albums
Posts: 231
Original Poster
Thanks all.

I've used all the techniques above. I've set iso as low as possible, usually 100 to eliminate noise as a sharpness factor, used a tripod, set the shutter speed in the thousands, and even done experiments with every lens I own shooting at three different apeture settings in an attempt to find the sharpest picture. I'll admit I may not be doing everything right, but when I zoom in on the camera or computer, I see soft edges. I upped the sharpness setting on the camera too. Maybe I'm getting the sharpest pictures possible, and am too critical. My photo's just don't 'Pop' like many of yours. I'm attaching a couple here. I apologize if I bog down anyones computer. I believe Mike S told me in another thread to zoom and crop to download. I'll try that. I'll attach them to my next reply.

Thanks again.
04-07-2010, 06:25 AM   #8
Site Supporter
GeneV's Avatar

Join Date: Oct 2008
Location: Albuquerque NM
Photos: Albums
Posts: 9,761
QuoteOriginally posted by Snydly Quote
Thanks all.

I've used all the techniques above. I've set iso as low as possible, usually 100 to eliminate noise as a sharpness factor, used a tripod, set the shutter speed in the thousands, and even done experiments with every lens I own shooting at three different apeture settings in an attempt to find the sharpest picture. I'll admit I may not be doing everything right, but when I zoom in on the camera or computer, I see soft edges. I upped the sharpness setting on the camera too. Maybe I'm getting the sharpest pictures possible, and am too critical. My photo's just don't 'Pop' like many of yours. I'm attaching a couple here. I apologize if I bog down anyones computer. I believe Mike S told me in another thread to zoom and crop to download. I'll try that. I'll attach them to my next reply.

Thanks again.
Your photos may be too large to attach. You will need to crop them (usually at 100%) and reduce the size to use the attachment feature of this forum. As an alternative, you can post them to another site and link to it.

I see you have two different bodies, and several lenses. Of those listed, the Taks would be lenses I would consider among the sharpest available, however you would need to be able to focus them properly.

Seeing the actual photos will help a lot. It depends a good deal on what you are expecting. I did a test this week of the DAL version of the kit lens which came with the K-x. I first tested hand-held with a flash, since the short duration of the flash should work something like a fast shutter speed, then used the flash with the camera on a tripod. The difference in sharpness was huge when pixel peeping but negligible at normal viewing.

04-07-2010, 07:01 AM   #9
Veteran Member
tokyoso's Avatar

Join Date: Jan 2010
Location: Tokyo
Photos: Albums
Posts: 723
I think many people who buy boat loads of lenses aren't necessarily looking for the sharpness holy grail. It seems to me that they enjoy the process of going thru different lenses, to see what they do differently. It's like a toy or hobby to them. There are people who love buying beatup cheap old lenses to clean them out and do comparison test shots and make blogs out of that.

It's probably more a combination of skill and circumstances, because to me most of these people's photos look sharp from one lens to another, but they just love going thru all these lenses...
04-07-2010, 07:02 AM   #10
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,312
as others have said, there are a lot of things to consider

For manual focus, make sure the eyepeice dipoter is correctly adjusted as well, I have not seen that comment yet.

Also sharpness is reletive. for the old rule of thumb shutter speed = 1/focal length, and also for depth of field the rule is based upon printing an 8x10 inch print from 35mm negative, considering the crop factor that would relate to a 4 by 6 print from an ASP-C sensor. It does not consider pixel peeping looking at perhaps 10% of the frame on a 22 inch screen (like I am at present)

You may also want to tell us what you are doing to post process, jpeg or raw.

I have found that most pentax cameras have the jpeg settings a little soft, and images can greatly improve by sharpening in PP (even jpegs)
04-07-2010, 07:21 AM   #11
MSM
Veteran Member
MSM's Avatar

Join Date: Dec 2007
Location: Alabama
Photos: Gallery
Posts: 994
I agree with everyone above. My first thought is technique. It certainly was the case for me. Also, I haven't seen it mentioned here. Have you tried to adjust for FF/BF? The K7 I believe offers adjustments for 20+ lenses. I have a K10d and keep it in the "debug" mode. Then I can make an adjustment with each lens. It is amazing what a difference in sharpness it made. As amazing is how different two lenses can be in terms of the setting adjustment.
04-07-2010, 07:40 AM   #12
Forum Member




Join Date: Feb 2009
Location: Vienna
Posts: 96
QuoteOriginally posted by pschlute Quote
Raw files are naturally unsharp
Care to elaborate? This is news to me.
04-07-2010, 07:55 AM   #13
Site Supporter
forensicscientist's Avatar

Join Date: Jun 2008
Location: DFW Texas and Maine - I commute :)
Posts: 866
have you tried turning SR off?

Odd suggestion I know...but oddly enough when I have SR on, I get a lot more pictures that just aren't sharp....no "pop". When I turn SR off, suddenly my pics are sharp and have the "POP" I'm looking for.

Its not the camera as its been this way since day one. I even sent it in to Pentax to have it looked at. Give it a try...who knows....

good luck,
mark
04-07-2010, 09:11 AM   #14
Veteran Member
Nesster's Avatar

Join Date: Oct 2006
Location: NJ USA
Photos: Gallery
Posts: 13,047
QuoteOriginally posted by Snydly Quote
I've used all the techniques above. I've set iso as low as possible, usually 100 to eliminate noise as a sharpness factor, used a tripod, set the shutter speed in the thousands, and even done experiments with every lens I own shooting at three different apeture settings in an attempt to find the sharpest picture.

I'll admit I may not be doing everything right, but when I zoom in on the camera or computer, I see soft edges. I upped the sharpness setting on the camera too. Maybe I'm getting the sharpest pictures possible, and am too critical. My photo's just don't 'Pop' like many of yours.
Thanks again.
You certainly seem to be doing the photography right... so the next question is how large are you magnifying the results in your pixel peeping?

As you have difficulty posting photo samples here - do you have such on another site you can link us to?

And can you post a link to some of the photos with the 'Pop' you like. Have you looked at such photos at the same magnification as you have looked at yours?

'Pop' consists of several things working together - absolute sharpness is not necessarily the most important factor - often pop consists of edge sharpening in the contrast range and lighting curves, though once these are there, absolute sharpness does make a difference.

Pentax doesn't do lighting like Canon, often the results are flat and realistic. People (me included) do add some post processing lightening of upper mids to get more of the Canon look

People, me included, do add unsharp mask, or other sharpening tool, though you have to be careful about the radius to avoid halos.
04-07-2010, 10:24 AM   #15
Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 703
QuoteOriginally posted by amaurosis Quote
Care to elaborate? This is news to me.
A raw file, opened in a raw converter without any settings applied (camera specific or otherwise) is a very dull beast. It requires contrast and colour enhancement, as well as sharpening applied to it before it will look like a decent image. This "processing" is the same as that done in-camera if you shoot jpeg.

As far as sharpening is concerned the raw file needs "capture sharpening" applied first (in the converter), then "output" sharpening applied (such as USM) if you convert to say a downsized jpeg direct from the raw converter.

If you have not noticed this before it may be because when you open a raw file in the Pentax software or other raw converter, some default settings are applied automatically. Try turning those off and see the difference.
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, lenses, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
k-7 sharpness / fine sharpness / fine sharpness 2 mattdm Pentax DSLR Discussion 10 12-12-2010 08:10 AM
Help with k-7 sharpness shaun2k Pentax DSLR Discussion 14 02-11-2010 06:25 PM
Sharpness VS Fine-Sharpness in k20d wasim_altaf Pentax DSLR Discussion 8 10-12-2009 11:41 AM
Sharpness vs Fine Sharpness on K20D morfic Pentax DSLR Discussion 2 11-02-2008 10:13 AM
Fine sharpness and sharpness move together on K20D 1.01 morfic Pentax DSLR Discussion 2 07-11-2008 09:18 PM



All times are GMT -7. The time now is 11:31 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