? on image details at distance

kini62

How much detail should there be in a full length portrait type shot from a distance far enough to be able to use a 70-85mm lens?

Should I be able to see things like eyelashes, hair detail, blemishes etc...

Also this would be with the lens at or near wide open. For example 85 1.8 at 1.8 to 2.8.

I have the K10 and 77mm ltd and I'm disappointed in the detail I get under these conditions.

Also if you could please post some crops from any images you may have.

Thanks
Gene

gus

Gene i recon you could get a lot more help if you could post a shot that is troubling you along with the exif data for the boffins to chew over.

Gus

Sam

gus wrote:

Gene i recon you could get a lot more help if you could post a shot that is troubling you along with the exif data for the boffins to chew over.

Gus

Listen you Kava deprived, hug les, degenerate, if your gona call us names at least use English…….the word is buffoon.

Sam

pathfinder

gus

Sam wrote:

Listen you Kava deprived, hug les, degenerate, if your gona call us names at least use English…….the word is buffoon.

Sam

Boffin...Buffoon. take your pick mate.

ziggy53

kini62 wrote:

How much detail should there be in a full length portrait type shot from a distance far enough to be able to use a 70-85mm lens?

Should I be able to see things like eyelashes, hair detail, blemishes etc...

Also this would be with the lens at or near wide open. For example 85 1.8 at 1.8 to 2.8.

I have the K10 and 77mm ltd and I'm disappointed in the detail I get under these conditions.

Also if you could please post some crops from any images you may have.

Thanks
Gene

Gene,

Popular Photography tested this lens:

http://www.popphoto.com/cameralenses/772/pentax-77mm-f18-limited-af.html

and their results seem to indicate that the "sweet spot" is at f8. That's far enough away from the f1.8 at wide open to indicate that the lens will be a bit soft at f1.8.

Couple that with a full length portrait, and I'm not surprised that fine detail is not evident, as many portrait lenses are even built to be a little soft at wide open aperture.

I'm betting that at f5.6 - f11, or so, you will see a much greater amount of fine detail, if that's your goal. I still doubt that individual hair will be obvious in a full length portrait, but there should be very well defined "hints" of individual hairs. Head and shoulder shots are where that kind of detail are usually obvious. (It partly depends on hair type too, as some hair is twice as thick as other hair. Human hair generally falls between 50 and 100 microns, and compared to even a 5 foot subject, 100 microns "ain't much".)

The Pentax K10D has 3872 x 2592 pixels, so assuming a 5 foot tall subject and completely filling the longer side of the imager (portrait configuration of a vertical subject) that would yield 60 inches divided by 3872 pixels, or a resolving power, if perfect, of 0.0155 inches. 100 microns is equal to 0.00393701 inches, so a thick human hair is only 1/4 of a pixel, even if perfectly imaged. That's why you should only see a "hint" of individual hairs.

Also, use a tripod when preserving fine detail is critical. You would be amazed at what is lost hand-held, even with the I.S. (Shake Reduction) turned on.

ziggy53

kini62

Thanks. I'm probably expecting too much. But I returned the camera and the one lens and will have to sell the 77.

The camera FFed nearly all the time at distances greater than 6 feet or so.

I had maybe one shot in 100 that was in focus or acceptably sharp.

My E-300 with the kit 40-150 did better wide open(3.5-4.5 depending on FL) than the 77ltd and K10 at F4.

Too bad the camera has a lot going for it, except for an obvious AF problem. This was my second body and both had AF issues.

Gene

ziggy53 wrote:

Gene,

Popular Photography tested this lens:

http://www.popphoto.com/cameralenses/772/pentax-77mm-f18-limited-af.html

and their results seem to indicate that the "sweet spot" is at f8. That's far enough away from the f1.8 at wide open to indicate that the lens will be a bit soft at f1.8.

Couple that with a full length portrait, and I'm not surprised that fine detail is not evident, as many portrait lenses are even built to be a little soft at wide open aperture.

I'm betting that at f5.6 - f11, or so, you will see a much greater amount of fine detail, if that's your goal. I still doubt that individual hair will be obvious in a full length portrait, but there should be very well defined "hints" of individual hairs. Head and shoulder shots are where that kind of detail are usually obvious. (It partly depends on hair type too, as some hair is twice as thick as other hair. Human hair generally falls between 50 and 100 microns, and compared to even a 5 foot subject, 100 microns "ain't much".)

The Pentax K10D has 3872 x 2592 pixels, so assuming a 5 foot tall subject and completely filling the longer side of the imager (portrait configuration of a vertical subject) that would yield 60 inches divided by 3872 pixels, or a resolving power, if perfect, of 0.0155 inches. 100 microns is equal to 0.00393701 inches, so a thick human hair is only 1/4 of a pixel, even if perfectly imaged. That's why you should only see a "hint" of individual hairs.

Also, use a tripod when preserving fine detail is critical. You would be amazed at what is lost hand-held, even with the I.S. (Shake Reduction) turned on.

ziggy53

Cameron

That's too bad... I hope your next big purchase goes better.

kini62 wrote:

Thanks. I'm probably expecting too much. But I returned the camera and the one lens and will have to sell the 77.

The camera FFed nearly all the time at distances greater than 6 feet or so.

I had maybe one shot in 100 that was in focus or acceptably sharp.

My E-300 with the kit 40-150 did better wide open(3.5-4.5 depending on FL) than the 77ltd and K10 at F4.

Too bad the camera has a lot going for it, except for an obvious AF problem. This was my second body and both had AF issues.

Gene

ziggy53

Gene,

Rats!

I see you and other Pentax shooters are having problems with the K10D, reported on FM and DPReview as well as here.

It does sound like QC problems and I too hope they get everything working properly because this is probably a pivital camera for Pentax. If they mess up the K10D introduction, a lot of loyal Pentax users are going to be torqued about it.

ziggy53