Is this lens faulty ? Or is it my expectations ?

audiobomber · 01-19-2009, 10:56 AM

Originally posted by lostkj233

I'm sorry to have to break the news to you, but the only real answer your going to get here is shoot in RAW and PP. Pentax's JPEG's aren't up to par with Canon or Nikon.

What nonsense. My K20D takes better jpegs than my friend's Canon 40D, even if he uses raw. Nothing better to do today than troll the Pentax forum?

Last edited by audiobomber; 01-19-2009 at 11:26 AM.

Alfisti · 01-19-2009, 11:01 AM

Originally posted by Gooshin

you cannot compare a point and shoot at F4 and an SLR at F4

because the point and shoot will have a very large depth of field corridor and the SLR wont, so it will be very easy to interpret the SLR shot as washed out or blurry compared the point and shoot, particulary when you shoot a complex geometrical structure with defined shapes like the OP did, especially since he decided to shoot it an angle.

That's why i said flat surface

If you try f/28 then you'll get a soft image everywhere due to diffraction.

Gooshin · 01-19-2009, 11:08 AM

ohh i get you, forgot about that.

in that case, the point is that you cant compare PS and SLR

asdf · 01-19-2009, 11:15 AM

"Is this lens faulty ? Or is it my expectations ?"

Neither. It's your methodology.

Alfisti · 01-19-2009, 11:30 AM

Originally posted by Gooshin

ohh i get you, forgot about that.

in that case, the point is that you cant compare PS and SLR

Yes you can chief, f/8 and f/4 is about right, we're testing sharpness on a flat surface not DOF here. The hard part is getting the same exact exposure at different ISo and aperture settings.

asdf · 01-19-2009, 11:31 AM

Off-topic:

Originally posted by Marc Sabatella

No lens is at its best wide open.

True, but oddly enough, according to photozone.de's tests, other than at 17mm, the center resolution of DA 17-70 SDM seems to be pretty similar from f/4 to f/11, while at 17mm the center resolution is actually best wide open.

Alfisti · 01-19-2009, 11:33 AM

Originally posted by asdf

True, but oddly enough, according to photozone.de's tests, other than at 17mm, the center resolution of DA 17-70 SDM seems to be pretty similar from f/4 to f/11, while at 17mm the center resolution is actually best wide open.

It's all beside the point because he has the compact at f/4 and the 16-45 at f/8.

asdf · 01-19-2009, 11:35 AM

Originally posted by Alfisti

It's all beside the point because he has the compact at f/4 and the 16-45 at f/8.

I was just responding to the other poster's generally accurate "No lens is at its best wide open." My comment wasn't specific to this thread. EDIT: I wasn't even talking about 16-45.

ghost · 01-19-2009, 08:11 PM

Originally posted by Alfisti

Well hang on, we're being a bit unhelpful. f/4 is about right as compared to f/8,
sweet spot for both lenses. The user has a right to compare the gear.

Do us a favour, set up a flat target (most use brick walls) and set up a tripod, make sure it's square (this is vital).

Fire off a few frames and re-sample the images to the same size (downsample the largest file to match the smaller one) then cut a crop from the centre at 100% magnification.

Here is an example i did recently with an unideal subject but you get the drift ....

D80 (10mp)

K100D (6mp)

Off topic, but the D80 has some serious noise issues! That ISO 800 shot looked like ISO 3200 when I first saw it!

On topic, if you properly focused on the shot, I think there might be something wrong with your lens... good luck!

Alfisti · 01-20-2009, 08:08 AM

Yes on both accounts, the Nikon 18-70 i have is a bit soft and the sensor is absolute rubbish IMHO.

holdgaj · 01-20-2009, 10:14 PM

OK, I'll do this (as soon as it stops snowing) I reshot the roof with F18 F22 - and the sharpness and resolution match the Canon shot - so I learned something.

Thanks for being helpful

pentaxmz · 01-20-2009, 11:01 PM

If I understand correctly, it seems that some of your are suggesting not to have the K20D create JPGs.

Currently, I have my camera set to create JPGs (highest quality) and only create JPGs plus RAW when I press the RAW button.

Are you suggesting that I only create RAW (all the time)? And perhaps set the RAW button for temporarily creating JPGs?

**Canada_Rockies** · 01-21-2009, 09:59 AM

Originally posted by pentaxmz

If I understand correctly, it seems that some of your are suggesting not to have the K20D create JPGs.

Currently, I have my camera set to create JPGs (highest quality) and only create JPGs plus RAW when I press the RAW button.

Are you suggesting that I only create RAW (all the time)? And perhaps set the RAW button for temporarily creating JPGs?

Many of us shoot only RAW. We believe that throwing away any data is not in our best interests. I shoot RAW, pass it through DxO for the DA lenses, then import into Lightroom where I basically have a look at the whole card full and make light tweaks as needed. I only create jpegs for email and Flickr and this forum.

Sodbuster · 01-21-2009, 04:23 PM

Wait, you cannot be saying that P&S take better pictures than dSLRs! I figured that the reason I'm having troubles with my k200d with focus and noise in this first 24 hours of having it, is that I haven't learned it all yet. It is much more complicated than my ME Super, or my Kodak z612 (which had all manual, if you call electrically-driven zoom and focus 'manual').

tibbitts · 01-23-2009, 10:39 PM

I haven't tested my own 16-45 in any scientific way, but it's kind of amazing that it seems to work with the barrel components so loosely attached to each other. I wonder if it would perform differently depending on how the front of the barrel was supported. But I've been satisfied with the results so far on my K100d.

I think you should do another test with a fairly flat subject, so you can better judge sharpness across the frame.

Paul

01-19-2009, 11:31 AM	#21
asdf Veteran Member Join Date: Jan 2009 Location: Canada Posts: 1,252	Off-topic: Originally posted by Marc Sabatella No lens is at its best wide open. True, but oddly enough, according to photozone.de's tests, other than at 17mm, the center resolution of DA 17-70 SDM seems to be pretty similar from f/4 to f/11, while at 17mm the center resolution is actually best wide open. Last edited by asdf; 01-19-2009 at 11:39 AM.

01-20-2009, 11:01 PM	#27
pentaxmz Veteran Member Join Date: Dec 2008 Location: Seattle Posts: 659	Don't create JPGs on camera? If I understand correctly, it seems that some of your are suggesting not to have the K20D create JPGs. Currently, I have my camera set to create JPGs (highest quality) and only create JPGs plus RAW when I press the RAW button. Are you suggesting that I only create RAW (all the time)? And perhaps set the RAW button for temporarily creating JPGs?

01-23-2009, 10:39 PM	#30
tibbitts Pentaxian Join Date: Apr 2007 Location: Oklahoma USA Posts: 2,193	my 16-45mm I haven't tested my own 16-45 in any scientific way, but it's kind of amazing that it seems to work with the barrel components so loosely attached to each other. I wonder if it would perform differently depending on how the front of the barrel was supported. But I've been satisfied with the results so far on my K100d. I think you should do another test with a fairly flat subject, so you can better judge sharpness across the frame. Paul

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01-19-2009, 10:56 AM	#16
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by lostkj233 I'm sorry to have to break the news to you, but the only real answer your going to get here is shoot in RAW and PP. Pentax's JPEG's aren't up to par with Canon or Nikon. What nonsense. My K20D takes better jpegs than my friend's Canon 40D, even if he uses raw. Nothing better to do today than troll the Pentax forum? Last edited by audiobomber; 01-19-2009 at 11:26 AM.

01-19-2009, 11:01 AM	#17
Alfisti Veteran Member Join Date: Mar 2007 Location: Toronto (for now) Posts: 1,748	Originally posted by Gooshin you cannot compare a point and shoot at F4 and an SLR at F4 because the point and shoot will have a very large depth of field corridor and the SLR wont, so it will be very easy to interpret the SLR shot as washed out or blurry compared the point and shoot, particulary when you shoot a complex geometrical structure with defined shapes like the OP did, especially since he decided to shoot it an angle. That's why i said flat surface If you try f/28 then you'll get a soft image everywhere due to diffraction.

01-19-2009, 11:08 AM	#18
Gooshin Veteran Member Join Date: Sep 2007 Location: Toronto, the one in Canada. Posts: 5,610	ohh i get you, forgot about that. in that case, the point is that you cant compare PS and SLR

01-19-2009, 11:15 AM	#19
asdf Veteran Member Join Date: Jan 2009 Location: Canada Posts: 1,252	"Is this lens faulty ? Or is it my expectations ?" Neither. It's your methodology.

01-19-2009, 11:30 AM	#20
Alfisti Veteran Member Join Date: Mar 2007 Location: Toronto (for now) Posts: 1,748	Originally posted by Gooshin ohh i get you, forgot about that. in that case, the point is that you cant compare PS and SLR Yes you can chief, f/8 and f/4 is about right, we're testing sharpness on a flat surface not DOF here. The hard part is getting the same exact exposure at different ISo and aperture settings.

01-19-2009, 11:33 AM	#22
Alfisti Veteran Member Join Date: Mar 2007 Location: Toronto (for now) Posts: 1,748	Originally posted by asdf True, but oddly enough, according to photozone.de's tests, other than at 17mm, the center resolution of DA 17-70 SDM seems to be pretty similar from f/4 to f/11, while at 17mm the center resolution is actually best wide open. It's all beside the point because he has the compact at f/4 and the 16-45 at f/8.

01-19-2009, 11:35 AM	#23
asdf Veteran Member Join Date: Jan 2009 Location: Canada Posts: 1,252	Originally posted by Alfisti It's all beside the point because he has the compact at f/4 and the 16-45 at f/8. I was just responding to the other poster's generally accurate "No lens is at its best wide open." My comment wasn't specific to this thread. EDIT: I wasn't even talking about 16-45.

01-19-2009, 08:11 PM	#24
ghost Senior Member Join Date: Jan 2008 Location: Barrie, ON Photos: Gallery Posts: 174	Originally posted by Alfisti Well hang on, we're being a bit unhelpful. f/4 is about right as compared to f/8, sweet spot for both lenses. The user has a right to compare the gear. Do us a favour, set up a flat target (most use brick walls) and set up a tripod, make sure it's square (this is vital). Fire off a few frames and re-sample the images to the same size (downsample the largest file to match the smaller one) then cut a crop from the centre at 100% magnification. Here is an example i did recently with an unideal subject but you get the drift .... D80 (10mp) K100D (6mp) Off topic, but the D80 has some serious noise issues! That ISO 800 shot looked like ISO 3200 when I first saw it! On topic, if you properly focused on the shot, I think there might be something wrong with your lens... good luck!

01-20-2009, 08:08 AM	#25
Alfisti Veteran Member Join Date: Mar 2007 Location: Toronto (for now) Posts: 1,748	Yes on both accounts, the Nikon 18-70 i have is a bit soft and the sensor is absolute rubbish IMHO.

01-20-2009, 10:14 PM	#26
holdgaj Junior Member Join Date: Jan 2009 Location: France Photos: Gallery Posts: 36 Original Poster	OK, I'll do this (as soon as it stops snowing) I reshot the roof with F18 F22 - and the sharpness and resolution match the Canon shot - so I learned something. Thanks for being helpful

01-21-2009, 09:59 AM	#28
Canada_Rockies Loyal Site Supporter Join Date: Nov 2007 Location: Sparwood, BC, Canada Photos: Gallery \| Albums Posts: 12,385	Originally posted by pentaxmz If I understand correctly, it seems that some of your are suggesting not to have the K20D create JPGs. Currently, I have my camera set to create JPGs (highest quality) and only create JPGs plus RAW when I press the RAW button. Are you suggesting that I only create RAW (all the time)? And perhaps set the RAW button for temporarily creating JPGs? Many of us shoot only RAW. We believe that throwing away any data is not in our best interests. I shoot RAW, pass it through DxO for the DA lenses, then import into Lightroom where I basically have a look at the whole card full and make light tweaks as needed. I only create jpegs for email and Flickr and this forum.

01-21-2009, 04:23 PM	#29
Sodbuster Inactive Account Join Date: Jan 2009 Location: SE Minnesota Photos: Gallery Posts: 109	Wait, you cannot be saying that P&S take better pictures than dSLRs! I figured that the reason I'm having troubles with my k200d with focus and noise in this first 24 hours of having it, is that I haven't learned it all yet. It is much more complicated than my ME Super, or my Kodak z612 (which had all manual, if you call electrically-driven zoom and focus 'manual').