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 1 
 on: Today at 03:22:05 AM 
Started by Michael Erlewine - Last post by shadowblade
Black-and-white photos are affected because the image is captured in colour first, before tonemapping curves are applied to produce a black-and-white image. These curves are generally not the same for every colour; therefore, there will be a fringing effect in the final black-and-white image.

 2 
 on: Today at 03:21:44 AM 
Started by smahn - Last post by BartvanderWolf
This effective aperture is what determines the diffraction that dominates the differences in required sharpening radius at narrower apertures. I've shown it before, but attached is the measured blur, and required radius to restore sharpness, for my EF 100mm f/2.8L Macro IS lens. It might be that other lenses show similar characteristics and resulting settings, but one can only be sure by measuring it, e.g. with the slanted edge method.

One more thing to add.

These specialized lenses can use different methods to achieve the close-up focusing capability, and also other lenses use internal focusing groups that may change the focal length and for that matter the entire optical performance. It then becomes a bit tricky to blindly apply corrected measurements that were made at a vastly different distance/magnification.

The difficulty with calibration of the close-up focusing performance of a lens is that the quality of the test target also becomes much more important. I'll try to do a test today if I get a chance, and determine the blur characteristics in close-up scenario's. For that I'll use a slanted edge made from self-adhesive pvc material (white on black, to reduce the contrast a bit), cut with a sharp knife for a clean sharp edge. Other possibilities are to use the edge of a razor blade, although then there are some issues with reflection.

Cheers,
Bart

 3 
 on: Today at 03:11:58 AM 
Started by Michael Erlewine - Last post by Michael Erlewine
I know that APO (apochromatic lenses) are designed for color and that non-APO lenses can have all kinds of ugly fringing, etc. My question is, do non-APO lenses affect B&W photography. Does the fringing only occur in color or is there anything from axial and lateral chromatic aberration that shows up in B&W photos? Probably a stupid question, but a question nevertheless.

 4 
 on: Today at 03:08:41 AM 
Started by chiek - Last post by BartvanderWolf
Both files are maximum quality JPEG.

Yes, now that I've downloaded the files, I've inspected the JPEG settings with 'JPEGsnoop', and that estimated the JPEG quality at well into the 98+ percent range for boht chrominance and Luminance, so it must be the amount of image detail compression that is possible.

Quote
I think 5ds pictures are more larger Depth of Field than CF-39MS because of sensor size. so more information than out-focus.

That could very well be a major part of it, and perhaps some differences in noise. There is also a bit of back focus on the Canon shot, it seems, so there is somewhat different detail in and out of focus.

Cheers,
Bart

 5 
 on: Today at 02:24:57 AM 
Started by BriansT - Last post by Erland
I can't say I've heard anything about that particular workflow.
However, I have recently started working with scanning my 35mm film. And one workflow I tried, and made my first choice was scanning a raw, which comes out from the scanner with a gamma of 1.0, and apply a custom made (by me) scanner color space with a gamma of 1.0 instead of the usual 2.2-ish. If he is scanning the darkroom print with a scanner using something similar workflow, it could mean he gets a linear trc, and then can match the tones in the print using a densitometer with the scanned version in say photoshop?
Just a thought really.

 6 
 on: Today at 01:34:16 AM 
Started by Edmond Junker - Last post by Edmond Junker
Hi to all,
My  almost new 3880 printer gives me message 003CR2 in the mid  of a printjob.No other indication.I need to start after I have wasted a A2 sheet of Baryta paper which is not for nothing.The next sheet will work properly.Generally I feed "rear manual" or simply "sheet",it does'nt matter.Any help would be kindly appreciated.Thanks

 7 
 on: Today at 01:14:02 AM 
Started by jeffreybehr - Last post by jeffreybehr
Next for sale are four lenses and a flash unit.  See terms of sale in the first post.

1. Sony G-series 70-300 F4.5-5.6 SSM.  See http://www.dyxum.com/lenses/Sony-AF-70-300mm-F4.5-5.6-G-SSM_lens439.html for more details.  I bought this used from B&H last summer.  It worked just finely and was a great-for-me compromise between optical quality--which was very good--and weight which is LOTS less than that of faster lenses.  This copy is as perfect as I've ever seen a used lens, with but one tiny mark on it.  Includes original front and rear caps, hood, carton, and user manual but not bag.  The prices at B&H are $998 new or $730 (in '9+' condition, which this one, too is).  My price is $650.












2. Sony 20mm F2.8.  See http://www.dyxum.com/lenses/Sony-AF-20mm-F2.8_lens302.html for more info.  This one is indeed used.  The glass is perfect, but the body has seen some use but is fully functional.  Includes Sony front and rear caps but no hood.  Prices at B&H are $748 new or $580 in condition 9.  Mine's only $500.












3. Sony HVL-F60M flash unit, purchased new from B&H.  See http://www.bhphotovideo.com/c/product/898312-REG/Sony_HVL_F60M_External_Flash.html for details.  Includes original pouch, foot, diffuser, colored panel for LED-light, user manual, carton.  Excellent condition.  $548 at B&H; mine only $275.












4.  Tamron SP 24-135/3.5-5.6 AF Aspherical AD MACRO, model 190D.  See http://www.dyxum.com/lenses/Tamron-SP-AF-24-135mm-F3.5-5.6--AD-Aspherical-IF-Macro_lens106.html for details.  This worked very well as a relatively high-zoom-ratio walkabout lens.  Is used but in at-least-good condition and is fully functional.  Glass is perfect.  Includes front and rear caps, original hood, and Kenko MC UV filter.  Only $140.










5. Tamron SP AF Di 90mm F2.8 MACRO lens, model 272E.  See http://www.dyxum.com/lenses/Tamron-SP-AF-90mm-F2.8-Di_lens117.html for details.  This is in at-least-very-good condition--glass is perfect and body is almost perfect.  This is one SHARP lens!  Includes original hood, rear cap, and pouch and aftermarket front caps (2).  Prices at B&H are $499 new and $399 used; mine's only $325.











 8 
 on: Today at 01:08:18 AM 
Started by N_Eyes - Last post by N_Eyes
Bump.

 9 
 on: Today at 01:07:06 AM 
Started by Sunshine7 - Last post by Sunshine7
Great, thanks all!

 10 
 on: Today at 01:01:56 AM 
Started by robdickinson - Last post by robdickinson
OK found the auto power off setting Smiley

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