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Forum: Flashes, Lighting, and Studio
10-17-2012, 01:26 PM
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How much money do you plan to spend?
What features are "must-have"? High speed sync? P-TTL wireless? Trailing curtain sync? Zoom head? Bounce and swivel? Auto mode? Multiple power ratio settings?
Do you plan to use the flash with cameras of different brands?
Do you prefer new or used?
The more details you provide, the better replies you'll get.
Without knowing the answers, I can still recommend a used copy of Sunpak 444D, 422D, 30DX, or 36DX. They all have:
- Auto mode with 3 aperture settings
- 5 settings of manual power ratios
- Bounce and swivel head
- Reasonable price, about $30 - $50.
- Compact and solid build
The nicest thing about them is that if later you acquire a better-featured (read: costlier) flash unit, the Sunpak doesn't become obsolete. It can still be used as a backup, or as a remote flash in multiple-flash setup.
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Forum: Pentax DSLR Discussion
11-01-2011, 07:08 AM
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The first 10 digits of most credit cards identify bank specific card details and are readily available, even online (the first six are the bank and the last designate other information - google 'credit card bin numbers' if you want to see for yourself!). The last 6 digits are typically the only unique numbers, along with the CVV code on the back of the card (so technically 9 unique digits, along with the expiration date).
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Forum: Pentax DSLR Discussion
06-09-2011, 09:10 AM
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The fact that your K20D is 5 years old makes it even more impressive.
(The K 20D was introduced in early 2008, just over 3 years ago.)
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Forum: Troubleshooting and Beginner Help
05-05-2011, 11:10 AM
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I used a regular unmodified K-7. The lens was the FA 35mm f2 at f8, ISO 100 and 15 seconds, on a tripod. My *ist DS is about 5 stops more sensitive to IR, but trickier to use.
IR photos are a kind of gray area for that. My image is somewhat fake, because "colors" don't exist in infrared. It's aready a post-processing effect. Some software and cameras come with digital filters to mimic the effect. With some PP skill, you could get close. I've taken the same scene with the filter on and off but never tried to get them to look the same.
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Forum: Troubleshooting and Beginner Help
05-05-2011, 08:33 PM
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PP can remove spectral elements; it can't add them. That's why IR and UV imaging are very important in science and forensics, because they show stuff we can't see visibly. The IR and UV portions of the EM spectrum convey different information than the visible portions. Without an IR-pass filter, that info just doesn't reach the sensor, and it can't be added in PP. UV is filtered out by sensor materials, so is not recorded either.
[Edit - slight correction. An IR-pass filter blocks visible light that would otherwise swamp-out the much lower-level IR light, thus allowing the IR to be recorded.]
Polarization is similar. It changes the angles at which light hits the sensor, and reduces glare that would otherwise be recorded. AFAIK digital filters can't polarize, else they'd be offered as in-camera options. Again, it's a matter of what spectra hit the sensor and are recorded, and which aren't. What isn't recorded is lost, gone.
And that's because most film emulsions ARE sensitive to UV light, while almost all digital sensors are made with UV-blocking filters. [NOTE: Some full-spectrum sensors exist, with no filtration, for specialized uses.] Skylight / UV filters are film-era relics, unnecessary now.
Clear optical glass filters (multicoated, of course) *would* be useful with digicams for protection in extreme environments. Meanwhile, I keep my lenses away from prying noses, tongues, and digits of humans and canines.
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Forum: Troubleshooting and Beginner Help
04-20-2011, 01:16 PM
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Power ratios in manual and aperture settings in auto are two different animals.
The OP asked how to set power ratio (full, 1/2, 1/4, ....) in manual mode.
The "A" settings on your Metz are aperture settings in auto mode.
You can use the A settings to trick the flash into emitting less power. But unlike with manual power ratio settings, the result is unpredictable.
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Forum: Digital Processing, Software, and Printing
04-02-2011, 08:21 PM
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It's there, for sure, in LR v3.3:
Develop > Lens Corrections > Tick 'Enable Profile Corrections' > Choose 'Profile' > Choose 'Make' > Select Tamron, Model 17-50 2.8 A16P.
At least for me.
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Forum: Pentax DSLR Discussion
03-28-2011, 07:30 PM
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I'll play.
These are with the K-5, Jpeg ***, High ISO NR OFF, cropped, PP'd with a surprisingly light applications of Topaz Denoise and Topaz InFocus, downsized for the web. I've posted them in a different forum here, but they're on topic.
ISO 10K Sigma EX 180 f3.5 APO DG Macro wide open through glass indoors. The light was mostly supplied by skylights on an overcast day.
ISO 12.8K Pentax DA 18-250 @ 200mm, f6.2 in relatively dim room light
I've found that Natural, with in-camera Sharpening at -4 gives me very good high ISO jpeg results. NR is expected at these crazy ISO sensitivities, and I haven't found anything as good as Topaz DN to smooth out the fine line details, and Topaz InFocus allows deconvolution sharpening without a lot of the artifacts that local contrast enhancement produces.
Scott
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Forum: Pentax DSLR Discussion
03-25-2011, 03:21 PM
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Forum: Pentax SLR Lens Discussion
03-23-2011, 11:49 AM
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Update:
I just completed my fine AF adjustment tests and even threw my DA Limited 70mm in the mix to see how it faired against the Sigma @ 70mm. For my final tests I decided to stop down one stop from wide open which put me at f/4 for the two zooms and f/3.5 for the DA Limited. I figured this is closer to the aperture range I typically use (f/5.6) but would still give me shallow enough DoF for my focus tests.
Results:
* The Sigma 24-70mm f/2.8 IF EX DG HSM easily out-performed the Pentax DA* 16-50mm at all focal lengths with the exception of 24mm where it was a draw....stands to reason as this is the extreme end of the Sigma but still mid-range for the DA* 16-50.
* The Sigma showed little-to-none "purple fringing" compared to the Pentax. Chromatic aberrations stuck out pretty bad on the Pentax even in the center of the image.
Sigma @ 70mm vs. DA Limited 70mm f/2.4....
* The DA Limited has a *slight* edge in outright shaprness but...
* The Sigma was superior in terms of purple fringing/chromatic aberation compared to the DA Limited. Once again, the DA Limited showed signs of chromatic aberration even in the center of the image.
Conclusion:
The Sigma 24-70mm really impressed me, enough that I'm likely to purchase one sooner than later and even sell my DA Limited 70mm. The sharpness of the Sigma is too close to call compared to the DA Limited while purple fringing was non-existant making my DA Limited 70mm redundant and even inferior to the Sigma...and I can't believe I'm even saying that as my DA Limited has always been my favorite lens in my bag.
Just to avoid confusion with other similar Sigma lenses, here's a link to the exact lens I tested: Sigma lens |
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Forum: Pentax SLR Lens Discussion
03-21-2011, 09:29 AM
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you already have a set of OK'ish AF zooms - I do not think that you will find something used for less than $150 used that will be noticeably better than your kits 18-55 + 55-300, even not talking about 28-75/2.8... constant 2.8 or 4 AF zooms where you can see a difference will be at least $200-300 range (unless in a very used condition)
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