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Forum: Pentax SLR Lens Discussion 02-11-2017, 02:45 PM  
500/4.5 SMC Takumar infinity focus issues?
Posted By rhodopsin
Replies: 19
Views: 3,751
Gerjan says the S-M-C 1:4.5/500 focus just past infinity.

I did adjust mine, however not using any screwdrivers. I did have to try many helical threading combinations to get part of the inner rear element group to gain 1mm more movement range. The two helicals need to be threaded onto correct positions from their maximum range of motion to allow full range of focus adjustment to include infinity & a little beyond -- that must seem like gibberish unless you have done it. :lol:

The improvement in infinity photo quality is easy to see; compares with quality closer.

Tip: Photograph a distant laser point to see how still is the camera mounting system.

For some fun mount the laser on the camera & walk over to the laser point to watch it move as an assistant simply walks the ground near the tripod!
Forum: Post Your Photos! 11-23-2014, 06:10 AM  
Nature Birds in clean & green background
Posted By rhodopsin
Replies: 13
Views: 776
I'm on dial-up internet so images load they load I'm wondering has somebody got birds on green screen? why would anybody want that -- pasting would require a lot of skill or luck? After I begin to see images with shallow dof against oof greenery...

#2 is clever but you can do much better than that. Is center bird different?!


#4 is AWARD WINNER -- submit everywhere to win awards!!!
Forum: Pentax SLR Lens Discussion 11-23-2014, 06:03 AM  
I need recommendations on a good quality Pentax lens. Not another 50mm. Thanks.
Posted By rhodopsin
Replies: 18
Views: 1,836
+1 Fast prime for portraits. I assume you say not another 50mm because you already have it -- 50mm is perfect portrait focal length for your camera -- if too close then +1 the 77mm...

If you want more reach for your other photo-making, +1 the 70-210.

Sandy Hancock you give good advice!
Forum: General Talk 05-31-2013, 08:42 PM  
What music are you currently listening to?
Posted By rhodopsin
Replies: 4,524
Views: 383,993
One From The Vault -- Great American Music Hall, San Francisco, 8-13-1975

Exceptional audio quality live concert recording
Forum: Pentax Camera and Field Accessories 03-10-2013, 04:21 PM  
UV filters - yes or no - which ones?
Posted By rhodopsin
Replies: 13
Views: 1,226
UV filter _might_ be needed at high altitudes where UV light can be intense, even overload blue channel.

UV filter protects lens from blowing sand, etc..

UV filter, even the very best, are prone to reflections.

In general, if a UV filter is necessary, use the very best to minimize IQ degrade from using it -- of course if a filter is used to avoid sacrificing the lens, consider roe. ;)

I use hoods instead of protective filters, except around blowing sand, when I use hood and filter.
Forum: Pentax SLR Lens Discussion 03-10-2013, 06:27 AM  
Did I just get a bargain?
Posted By rhodopsin
Replies: 10
Views: 1,501
Mount those Minolta-mount lenses on a Nex. Used Nex-3 go for ~US$200 (or less :))
Forum: Pentax SLR Lens Discussion 03-09-2013, 06:03 PM  
Problems with Super Takumar 50mm 1.4 on 5DmkII
Posted By rhodopsin
Replies: 34
Views: 3,748
Latest info on SP 90 "spot", from somebody who talked with Tamron employee at a trade show, is the rear compensator group of elements is uncoated (thus the reflections), that the lens is designed for low contrast lighting at high magnifications. I suspect other lenses that exhibit these spots have uncoated elements.

Thorium doped glass is well known, however, Gerjan van Osten says, in "The Ultimate Asahi Pentax Screw Mount Guide" (1999), there is thorium in one of the coatings. Since Mr. van Osten had access to Asahi Pentax personnel and documentation, I tend to believe him.
Forum: Pentax SLR Lens Discussion 03-01-2013, 10:56 AM  
Why not bring back the legendary glass?
Posted By rhodopsin
Replies: 110
Views: 8,123
Excellent point! :D (has Pentax/Ricoh mopped themselves into a corner? :lol:)
Forum: Pentax SLR Lens Discussion 03-01-2013, 10:36 AM  
Takumar repair
Posted By rhodopsin
Replies: 2
Views: 1,163
I've been inside from front -- simply focus close, grab front section & unscrew it.

For entering from camera side, check disassemble instructions for 135/3.5 or even 50/1.4 or 55/1.8. The disassemble is similar. Involves "chinese puzzle" moving of aperture ring. Likely, A/M switch is simply bent. Straighten ONCE, i.e. do not stress metal too much or it will break.

Caveat: Is switch really stuck or: On S-M-C Takumars there is a second tiny pin (besides the diaphragm pin) which must be depressed before A/M switch can be switched from Auto to Man.
Forum: Do-It-Yourself 03-01-2013, 10:35 AM  
Build AC adapter for the Pentax K-r or K-30
Posted By rhodopsin
Replies: 9
Views: 4,578
Nice work! Thanks for sharing!
Forum: Pentax SLR Lens Discussion 03-01-2013, 10:27 AM  
Why not bring back the legendary glass?
Posted By rhodopsin
Replies: 110
Views: 8,123
Why would Pentax reproduce legacy glass when there is so much of it available places such as here in marketplace and ebay?
Forum: General Talk 03-01-2013, 10:26 AM  
Shipping small item to Canada
Posted By rhodopsin
Replies: 15
Views: 1,404
+1 After many packages shipped to CA via USPS, no problem here...
Forum: Digital Processing, Software, and Printing 02-26-2013, 04:09 PM  
Strange issue with some photos in photoshop.
Posted By rhodopsin
Replies: 6
Views: 1,045
CMYK over sRGB?! Sorry, I think that is nonsense.

Opening (viewing) a raw file requires the application of white balance multipliers, one for each color channel, R, G, & B. After multiplying, one or more of the channels can "blow out", or be overexposed.

Likewise, the raw file uses 16-bit colors, however, Adobe products that open raw files discard a color bit, using only 15 bits. I think what you see is the loss of that one bit -- darker portions of the image get lost.
Forum: Pentax DSLR Discussion 02-26-2013, 07:58 AM  
Once again, priorities shift, feel I may have outgrown Pentax :(
Posted By rhodopsin
Replies: 59
Views: 5,486
Newer cams have more "confident" AF...

Newer cams have Video features

Newer cams from any manufacturer haven't improved that much, i.e., the wait could BE that long...

Sure. Any brand of newer camera with those features will suit your needs (as stated) well.

Reconcile with

i.e. wishing for Pentax, hoping for Nikon recommendations? Does this have anything to do with sister having a newer better camera? :lol:
Forum: Pentax SLR Lens Discussion 02-23-2013, 08:33 PM  
What makes a lens "3-D"?
Posted By rhodopsin
Replies: 60
Views: 5,771
3-D "pop" has more to do with position of subject within dof, distance from background, and lens drawing characteristics at the transition between in-focus and out-of-focus areas -- lenses with more micro-contrast seem to exhibit the pop more than those with less of it... IOW, ANY lens is capable of 3-D pop, given proper dof & distance to background.


Some lenses get known for 3-D pop more than others because they are more often used with dof setting, subject & background distances conducive to it...
Forum: Pentax SLR Lens Discussion 02-23-2013, 02:07 AM  
To Deglass or Not? PKA macro teleconverter
Posted By rhodopsin
Replies: 21
Views: 3,749
:o !

Forum: Pentax SLR Lens Discussion 02-22-2013, 11:18 AM  
To Deglass or Not? PKA macro teleconverter
Posted By rhodopsin
Replies: 21
Views: 3,749
TC and focusing Macro-TC, in general, do not make good extension tubes or focusing helicoids.

The problem with de-glassing is the lens element mounts block part of the light path, causing vignette.
Forum: Troubleshooting and Beginner Help 02-14-2013, 05:51 AM  
sooo my firmware upgrade is going
Posted By rhodopsin
Replies: 22
Views: 1,834
If Pentax firmware works like Canon firmware (I'm reasonably certain with all cameras, Canon, Nikon, Pentax, Sony, & etc., choosing firmware update from the camera menu only sets the boot flag on the card -- if the camera finds a usable autoexec.bin file in the root directory of the card, the camera will boot from the card instead of from internal memory.

Common mistakes:

1 failing to extract files from archive before copying to card (i.e. copying archive file to card)
2 failing to extract files from archive before copying to card (i.e. extracting archive files directly to card instead of to a directory that gets copied to card)
3 failing to format card in camera before removing it & using card reader to copy files from archive to card

I made the last two mistakes :oops:
Forum: Digital Processing, Software, and Printing 01-19-2013, 03:53 AM  
Any hope to calibrate monitor?
Posted By rhodopsin
Replies: 42
Views: 4,043
On wikipedia page Color space - Wikipedia, the free encyclopedia is this image comparing RGB and CMYK Color Spaces:

Forum: Digital Processing, Software, and Printing 01-17-2013, 10:10 AM  
Any hope to calibrate monitor?
Posted By rhodopsin
Replies: 42
Views: 4,043
Sit up when monitor is calibrated -- that way you'll have good posture when editing photos, having to sit up straight. ;) (Yes IPS monitor has very much less angle-viewing color-change problem: IPS Monitor List: Displays Using IPS Panels )

Monitor calibrated by Win 8 is for viewing Win 8. For printing photos, turn down monitor contrast and brightness until what you see on screen is as dark as what gets printed. Now try editing & printing after making screen photo brighter -- the print should look bright like the photo on the screen.

Monitor contrast should match paper contrast (3-4 stops total, I think...), then monitor brightness adjust so white screen matches white photo paper.
Forum: Welcomes and Introductions 01-17-2013, 09:59 AM  
Hello, everybody,a newcomers from China Shanghai
Posted By rhodopsin
Replies: 4
Views: 1,048
Welcome Afterburning turbofa

Point camera at California, I wave to you! Hi :cool:
Forum: Pentax SLR Lens Discussion 01-02-2013, 07:30 PM  
Help me choose which lens
Posted By rhodopsin
Replies: 14
Views: 1,939
Here's a snap made with cheap Soligor "wundertube" 400/6.3, aperture is wide open at f/6.3, distance about 10 meters:

Forum: Pentax SLR Lens Discussion 01-02-2013, 07:21 PM  
Help me choose which lens
Posted By rhodopsin
Replies: 14
Views: 1,939
Wundertube is better for wildlife imho. DOF is very shallow in mirror lens -- mirror lens is harder to manual focus accurately on moving wildlife. Mirror lens focus helical is steep -- a small amount of turn makes a big difference in focus distance. Wundertube has longer focus throw -- easier to focus/harder to mis-focus.. Wundertube has faster f/# -- higher shutter speeds are possible, for hand holding, etc.. Wundertube will set you back US$30-40, while mirror lens costs more, takes more skill to use, and can be used in fewer situations. Mirror lens is "stopped down" by using ND filters -- there is no change in DOF or image IQ. Wundertube can be stopped down to f/22 or even f/45 -- IQ is sharpest at f/8 or f/11 and DOF changes with f/# change. Wundertube is pretty light weight -- as light or lighter than mirror lens...
Forum: Digital Processing, Software, and Printing 01-02-2013, 12:34 PM  
Image transfer from camera to computer
Posted By rhodopsin
Replies: 21
Views: 3,294
+ 1 !!!
  • Minimizes wear to card slot connector pins, and possibilities for damage to pins.

Forum: Pentax SLR Lens Discussion 01-02-2013, 12:32 PM  
Help me choose which lens
Posted By rhodopsin
Replies: 14
Views: 1,939
Those 400/6.3 "wunder tube" lenses are actually pretty good! The Tokina versions (various brands) are the best of the lot imho. No problem handheld as long as shutter speed is sufficient -- at least 1/400 seconds, faster for close subject. Excellent value, the next step in IQ is a huge price increase.

A T2-mount 400/6.3 wunder tube should cost US$30-40, maximum, although somebody in Australia put an EOS adapter on some, described them as "EOS Lens" and sold them for hundreds of US$...keep looking!
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