Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-20-2011, 11:38 AM   #16
Pentaxian
Marc Sabatella's Avatar

Join Date: Sep 2006
Location: Denver, CO
Photos: Gallery
Posts: 10,686
There's a difference between what's sharp enough to count as in focus according to a DOF / hyperfocal ditance formula, versus what's sharp enough to stand up to pixel peeping. I wouldn't assume you don,t need to focus just because a formula says it should be in focus. The formulas assumes a typical print viewed from a typical distance, not an image viewed at 100% from a foot away on a computer monitor.

10-20-2011, 12:50 PM   #17
Veteran Member
Lloydy's Avatar

Join Date: Aug 2007
Location: Shropshire, UK
Posts: 1,114
Elsinor 24mm f2.8, also found badged as Clubman, and a few other names as well. Stunning lens that's cheap and overlooked.
10-20-2011, 01:33 PM   #18
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 27,474
QuoteOriginally posted by Marc Sabatella Quote
There's a difference between what's sharp enough to count as in focus according to a DOF / hyperfocal ditance formula, versus what's sharp enough to stand up to pixel peeping.
1+


Steve
10-20-2011, 01:38 PM   #19
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 27,474
A lot depends on what format you are shooting. If you are doing APS-C on a Pentax dSLR, a 28mm is really not very wide (pretty close to normal to be honest) and a 24 is just getting close to being wide.

If you want sharp and very wide and relatively low-priced, the Zenitar 16/2.8 Fisheye might be your best bet, though it is hardly cheap anymore. There are legacy lenses from Tamron and Vivitar in the 17mm range that might also work for you.


Steve

10-20-2011, 07:02 PM   #20
Site Supporter




Join Date: Jan 2009
Location: Victoria, BC
Photos: Gallery | Albums
Posts: 310
I'm surprised no one said K28/3.5. Hard to beat; sharpest of all 28mm perhaps.
10-21-2011, 03:50 AM   #21
Senior Member




Join Date: Jan 2010
Location: Lynchburg Virginia
Posts: 182
I think the key is to be patient, save your sheckels, and buy something that fits the bill the first time. Its definitely worth saving for a Sigma 10-20 or a DA15.......or whatever. I love 28mm, but I always miss the width when I'm out galavanting on my early morning photographing sessions.
10-21-2011, 04:00 AM   #22
Site Supporter
Douglas_of_Sweden's Avatar

Join Date: Apr 2008
Location: Stockholm
Photos: Gallery
Posts: 3,353
Besides that I think you could benefit from following some of the good advices you have got here for how to make your current lenses perform better, if you are after a wide lens on budget (and 28 and 24mm lenses aren't really wide on an APS-C) there are not many decent alternatives. One would be the Cosina 20mm f3.8. Well built, good optics, underrated, can be found for modest prices. I think it exist under several other labels, including Vivitar.
10-21-2011, 06:26 AM   #23
Junior Member




Join Date: Sep 2010
Location: Pennsylvania
Posts: 42
Original Poster
@paulh
> What apertures are you using? You might need to stop down more (f/8-f/11) to achieve max sharpness.
Usually around f8 for group shots. You'll be able to see in the example picture I posted.

@RioRico
>Technique? If you're handholding your 18-55 wide-open at 18/3.5, loss of detail isn't remarkable.
When I'm shooting a group, I most always use a tripod (for head swaps, etc).

@Laurentiu Cristofor
>Can you describe in a bit more detail your Sears lens?
From the front of the lens: AUTO Sears MC, Japan, metal. I'm enclosing a picture. This is not a picture of
my lens, it is one from the internet. But it is identical to what I use.


Everyone else, thank you SO much for your input! I've added every single lens you recommended to a document so I can
search for them. So far, I haven't found one of them available to purchase. Hopefully something will come up soon. I appreciate your input so far!

Also, I'm enclosing a picture that shows comparison of the details. This is shot with my 50mm. (I'm also enclosing a picture of the 50mm for @Laurentiu Cristofor.

Thanks again everyone. Really appreciate the recommendations. EXACTLY what I was hoping for.

(this example is zoomed in for emphasis....)

Attached Images
   

Last edited by mishmatta; 10-21-2011 at 06:27 AM. Reason: forgot to add something
10-21-2011, 09:02 AM   #24
Junior Member




Join Date: Sep 2010
Location: Pennsylvania
Posts: 42
Original Poster
Also, I forgot to mention: i checked the lens database here BEFORE I purchased my promaster 28-105 and it got a pretty decent rating (9.0). Said it was sharper than the kit 18-55. So it's hard to know what to buy and what not to buy. I thought I was getting a pretty decent walk-around lens by the reviews, but personally I don't think it's sharper than my kit (if it can even compare).

I feel my 50mm is my best lens, with the kit lens behind it. Don't laugh, but my quantaray 70-300 that everyone curls their noses at is a nice third in my collection.

One day I'll hit it big, and be able to pay the mortgage, feed my 3 kids AND purchase the lenses I *really* want.
10-21-2011, 09:43 AM   #25
Veteran Member
Pentaxor's Avatar

Join Date: May 2009
Location: Vancouver, B.C.
Photos: Gallery
Posts: 6,513
QuoteOriginally posted by regor Quote
I'm surprised no one said K28/3.5. Hard to beat; sharpest of all 28mm perhaps.
K28/3.5. happy now?
10-21-2011, 10:28 AM   #26
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
FYI the Sears 50/1.7 lens you have pictured was made by Cosina. I have had a couple copies of the nicely sharp f/2 version and wouldn't mind adding the f/1.7 version to my accumulation of lenses. The Cosina 50's have a good reputation.
10-21-2011, 10:48 AM   #27
Pentaxian
paulh's Avatar

Join Date: Sep 2010
Location: DFW Texas
Photos: Gallery | Albums
Posts: 13,883
I think the problem is that you're blowing up a detail from a shot taken at 75 ft, and expecting it to be as sharp as a shot taken from 5 ft. There will usually be artifacts, pixelation, maybe some lens distortion, and other degradations that occur. What you are doing is the equivalent of "digital zoom" on a PnS camera, which is going to show fuzziness & loss of detail. Your group shot probably looks fine viewed normally, no? I'll leave it to the more knowledgeable members here to expound on this (if I'm correct ).

Last edited by paulh; 10-21-2011 at 07:20 PM.
10-21-2011, 11:35 AM   #28
Veteran Member




Join Date: Mar 2010
Location: NewYork
Posts: 899
One you might want to look for if you are wanting to go cheap is a ricoh rikenon 50mm 2.0. While is seems how good they are very from lens to lens, its not uncommon to hear people make comments like its the sharpest lens ever made (if you get a good copy). It is also a less appreciated lens price wise. I paid about 6-7$ shipped for mine off ebay in nice condition and it is sharper than any other lens I own. If a 50mm will work for you, it might be worth a try, especially considering how cheap they can be had.
10-21-2011, 01:20 PM   #29
Veteran Member
Laurentiu Cristofor's Avatar

Join Date: Nov 2009
Location: WA
Photos: Albums
Posts: 3,044
QuoteOriginally posted by paulh Quote
I think the problem (IMO) is that you're blowing up a detail from a shot taken at 75 ft, and expecting it to be as sharp as a shot taken from 5 ft. There will usually be artifacts, pixelation, maybe some lens distortion, and other degradations that occur. What you are doing is the equivalent of "digital zoom" on a PnS camera, which is going to show fuzziness & loss of detail. Your group shot probably looks fine viewed normally, no? I'll leave it to the more knowledgeable members here to expound on this (if I'm correct ).
I agree - I don't see a sharpness problem.

QuoteOriginally posted by RioRico Quote
FYI the Sears 50/1.7 lens you have pictured was made by Cosina.
And I thought that was a Ricoh model. Good to know it's a Cosina. I also have a plastic Sears 50/2 which looks exactly like a plastic Ricoh 50/2 I've seen around, so I'm sure that one is Ricoh. This 50/1.7 is maybe a bit less sharp wide open than that 50/2, but other than that, there aren't many obvious differences. The 1.7 is built to last - it feels more solid even than K/M lenses. These Sears 50s are good lenses.

@mishmatta - you have a good lens there in that Sears. It's going to be hard to find something significantly better under $100.
10-21-2011, 01:53 PM   #30
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
QuoteOriginally posted by Laurentiu Cristofor Quote
I agree - I don't see a sharpness problem.
Ditto. Just enlargement artifacts. And for that degree of enlargement, not many artifacts!

QuoteQuote:
And I thought that was a Ricoh model. Good to know it's a Cosina. I also have a plastic Sears 50/2 which looks exactly like a plastic Ricoh 50/2 I've seen around, so I'm sure that one is Ricoh. This 50/1.7 is maybe a bit less sharp wide open than that 50/2, but other than that, there aren't many obvious differences. The 1.7 is built to last - it feels more solid even than K/M lenses. These Sears 50s are good lenses.
My Rikenon 50s are metal M42s, not plastic-body PKs. The Sears feels more like a similar Chinon but the markings differ, whilst that Sears and those Rikenons have similar markings, but so do some lenses I attribute to Tokina. Tracking lens lineage through the production+marketing maze is a daunting task.

QuoteQuote:
@mishmatta - you have a good lens there in that Sears. It's going to be hard to find something significantly better under $100.
My Sears 50/2's were US$4 and $10 (and I sold the $4 one for $11). I think I've seen the f/1.7 for around US$30. My ultrasharp M42 Rikenon 50/2 and 55/1.8 were US$10 and $6 respectively last year; I haven't checked current prices. These are all up to the standards of the M50/1.7 and SuperTak 55/1.8 and Petri CC 55/1.8, i.e. some of the sharpest glass around. They're truly fine bargains.
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!
details, f2.8, focus, image, k-mount, kit, lens, lenses, love, pentax lens, quality, slr lens, thanks
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
What's a good cheap wide angle lens? hockmasm Pentax DSLR Discussion 16 02-06-2011 01:12 PM
Any recommendations for a dslr & lens repair center? Immunogirl Pentax DSLR Discussion 4 12-16-2010 04:38 PM
Cheap AND sharp autofocus 300mm? rob1234 Pentax SLR Lens Discussion 37 12-07-2010 11:48 PM
Cheap - Wide Angle Lens Converter cdurfor Pentax SLR Lens Discussion 7 02-23-2010 11:57 PM
Cheap manual lens on cheap extension tube with cheap flash! Also cats. pasipasi Post Your Photos! 12 08-28-2008 04:43 PM



All times are GMT -7. The time now is 12:42 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