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Forum: Pentax K-3 Photo Contest 05-01-2014, 02:03 PM  
Travel Surf Pittsburgh
Posted By aaronwarnick
Replies: 1
Views: 658
This photo was taken on the back of a boat on the Mon. River in Pittsburgh, PA.

For those of you not familiar with the United States, not a whole lot of surfing goes on in Pittsburgh... the climate is closer to Glasgow's than it is to Barcelona's.
Forum: Post Your Photos! 03-06-2014, 01:39 AM  
Streets Moments to cherish whole life
Posted By yusuf
Replies: 10
Views: 485
They really made me smile....hope you like it too, please share your comments if you do.


Frozen Moments

Yusuf
Forum: Post Your Photos! 03-03-2014, 12:34 AM  
Travel Highland Riders
Posted By richard balonglong
Replies: 19
Views: 1,426
Highland Riders
- Riders from different horse-back-riding associations of Baguio City and Benguet province in Philippines have fun and race with their horses around the track and field oval of Baguio Athletic Bowl on March 1 during the annual Pony Boys Day.

Forum: Pentax SLR Lens Discussion 02-08-2013, 11:57 AM  
SMCP-DA* 300mm + reversed DA35 Macro
Posted By Nass
Replies: 41
Views: 3,215
Forget about reversing the 35 onto the 300, it'll be rubbish. You'll always be diffraction limited. The thing is, at 8:1 macro you're going to get diffraction limitation with just about any combo of reversed lens... Remember, effective aperture is fstop*(mag+1). So f/8 at 8:1 is actually f/72, hopelessly diffraction limited. This is why we use microscope objectives at these sort of magnifications as they give you the best f/stop, and the Nikon infinites have been found to be especially good. For 8:1 I'd use my Nikon CFI Plan 10x/0.25NA 10.5mmWD on a 150-200mm tube lens or on a Raynox at infinity... but 10.5mm isn't exactly a huge working distance.

Objectives will get you the highest IQ by miles but you're looking at small working distances. If you want a longer working distance you might need to stretch to a Mitutuyo 10x infinite LWD (stands for "long working distance"), but they're not cheap... The longer the WD the higher the price basically, and in the infinite objective game nikon and mittys are really the only 2 major players in the game. Because they don't rely on eyepiece correction, so you can use them with a non-corrected tube as well.

Hope this helps a bit :)
Forum: Pentax SLR Lens Discussion 02-06-2013, 06:29 PM  
SMCP-DA* 300mm + reversed DA35 Macro
Posted By baro-nite
Replies: 41
Views: 3,215
Did you follow this link from that flickr page:

Nikon 10x Microscope objective comparison | Flickr - Photo Sharing!

A quick eBay search turned many copies of both, and this is right in the magnification range you want. This is all very new to me so I don't know what is going to work best for you, but 8x magnification on an f/4 lens just sounds like trouble to me -- as good as the DA* 300 is, it improves on stopping down at least a little, which you can hardly afford to do at those magnifications.
Forum: Pentax DSLR Discussion 01-23-2013, 09:31 PM  
30$ for a lens cap?
Posted By SOldBear
Replies: 48
Views: 5,187
About the $30 (or 30$) lens cap....

My first "real" job out of college was a custom chip designer. I worked with a manufacturer. At the time, the prototype lead time (the time when the customer released the design for manufacturing until they received 10 prototype chips back) was 3 weeks. Many customers wanted to "expedite" this. The cost of "expedite" was $10,000 a day (note that new EE grad was making around $35K/year). From what I knew, the procedure at the factory was pretty simple: someone just had to bring the design up in the queue.

When I asked the manufacturer as why a simple job cost so much, they told me, "Because we don't want to do it."

Look, Pentax is not in the business of selling lens caps. Pentax wants to sell cameras, lenses, and flashes. If Pentax wanted to sell lens caps, they'd have to set up different manufacturing flows, different distribution procedures, different warehouse practices, ... Do you know how long a lens cap sits on the warehouse shelf before someone buys it? Look at the automotive manufacturers, they have a network of dealerships to deal with selling parts, but have you compared the price of a Honda cd player at a Honda dealer vs that of a Pioneer cd player at Wal-Mart?

Why does it cost $30 for a Pentax lens cap? Because Pentax doesn't want to sell it.
Forum: Photographic Technique 01-21-2013, 07:33 PM  
Super close macro?
Posted By Allison
Replies: 58
Views: 4,585
I haven't yet needed more magnification than my macros and some extension tubes, so I am not experienced in the lens stacking, but I understand it. Just remember that since you don't need autofocus and you do need an aperture ring, there are some good quality glass options out there that aren't too expensive.

As far as rails go, of course, that $600 one is beyond sweet...but until you are ready to jump in that far, look at the cowboy student ones on amazon and the flashpoint ones on adorama. I know there are a few people on the forums who have had success with them. I have a coyboy studio one that I got for Christmas and so far I have been very happy.

I am jealous of you getting a D800! I am still holding out hope that we will see the FF from Pentax in 2013. You might want a rail when you get the D800 since the FF sensor is going to give you a shallower DOF.
Forum: Photographic Technique 01-22-2013, 12:15 AM  
Super close macro?
Posted By Not a Number
Replies: 58
Views: 4,585
Forum: Pentax DSLR Discussion 01-21-2013, 09:11 PM  
30$ for a lens cap?
Posted By oguzgel
Replies: 48
Views: 5,187
Get 5 x Lens Cap Keepers for $2.17 from Amazon and never lose or drop your lens caps from now on :-)
Forum: Photographic Technique 01-21-2013, 02:34 PM  
Super close macro?
Posted By audiobomber
Replies: 58
Views: 4,585
Note that a 100mm f4 macro with 68mm extension tubes gives a maximum magnification of 1.2:1, which is only 20% higher than your D FA macro on its own. With a Raynox 250 on your lens, you're getting about 3:1 IIRC, so it's no wonder you have to contend with short subject distances and miniscule DOF.

Here's a page that will help you figure out magnifications:
www.peterforsell.com
Forum: Photographic Technique 01-21-2013, 07:11 AM  
Super close macro?
Posted By Allison
Replies: 58
Views: 4,585
You are definitely getting ahold of the stacking thing and each image is getting better. Moving to f16 was the right move. Did you get the rail yet? The one you ordered puts my cheap cowboy studio one to shame! I guess that you are enjoying the whole super close macro thing.
Forum: Pentax K-5 01-18-2013, 12:15 PM  
USB cable for K5
Posted By boriscleto
Replies: 17
Views: 7,489
Forum: Photographic Technique 01-16-2013, 02:28 PM  
Super close macro?
Posted By Allison
Replies: 58
Views: 4,585
I have several led flashlights that I use for continuous lighting with marco, but I also tend to just use my flash a lot. I think you are right in going with continuous if you are stacking, so the flashlights should work fine. Just fine a way to mount them in a steady, constant position.
Forum: Pentax DSLR Discussion 01-13-2013, 05:20 PM  
Pentax: Is it really that bad for moving objects?
Posted By kkoether
Replies: 132
Views: 15,876
That's one reason I keep the F-Stop in the F8 to F16 range so the DOF isn't too shallow. It's not perfect but it helps.





Forum: Pentax K-5 01-13-2013, 07:29 PM  
Sad sad day....
Posted By stormtech
Replies: 36
Views: 15,578
Sorry to hear of your misfortune.

I just did an on-line quote at a camera repair facility - LCD repair for the K-5 is $144. Here is the specific of the repair on the site:






QuoteQuote:




Choose this repair for all of your LCD screen problems such as:
  • Cracked LCD screen

  • Photos don't display properly on the screen but look fine when downloaded to the computer




Maybe contact them to see if this includes the entire scree replacement or not.

Pentax K5 Dslr Repair | United Camera Repair
Forum: Photographic Technique 01-15-2013, 06:12 AM  
Super close macro?
Posted By audiobomber
Replies: 58
Views: 4,585
The Raynox adapter is specified to clip onto any lens with a 52-67mm filter size. For the D FA 100 (49mm filter size), unscrew the Raynox element from its adapter and screw it into a 49 to 43mm step down adapter. The diopter then screws into the end of the lens like any filter.

Focus is always a challenge with macro, more so with extreme macro. For a studio or lab, a macro rail is highly recommended. You can use very small apertures for DOF, accepting some loss of IQ from diffraction, or you can use the lens at its peak sharpness and focus stack, in which case a macro rail would be invaluable.

Lights cause reflections. You don't need super bright lighting for a static object, just use a longer exposure time. Consider constant lighting rather than a strobe for better control. Either way, constant or flash lighting, you'll want a softbox. You can make your own soft box (light tent) with a sheet of fabric hung over a frame if you don't want to incur any cost. http://strobist.blogspot.ca/2006/07/how-to-diy-10-macro-photo-studio.html
Forum: Flashes, Lighting, and Studio 01-15-2013, 01:42 AM  
Project images against cyc wall for backdrops?
Posted By adwb
Replies: 5
Views: 1,520
I agree shoot green screen
Forum: Flashes, Lighting, and Studio 01-14-2013, 05:50 AM  
Project images against cyc wall for backdrops?
Posted By bdery
Replies: 5
Views: 1,520
Hello from Quebec!

I believe you would be better off adding the image in post-processing. Your studio lamps will wash out a significant part of the image being projected. If you use a powerful enough projector to overcome your strobes, it will mess with your subject lighting.

Good luck with your project!
Forum: Photographic Technique 01-14-2013, 12:03 PM  
Super close macro?
Posted By audiobomber
Replies: 58
Views: 4,585
This post shows a D FA 100 macro at 1:1 and magnification with a Raynox 250 added (no cropping).

https://www.pentaxforums.com/forums/lens-clubs/74221-raynox-macro-club.html#post753591

IME, a Raynox will give you quality equivalent to reversing a lens on the end of the 100mm macro, and better than a TC. TC's cause more aberrations (fringing, loss of sharpness).

Adding more glass, whether it's a Raynox, TC or reversed lens onto the end of a main lens gives slightly lower quality than using a single short lens with reversing ring, or extension tubes.
Forum: Photographic Technique 01-13-2013, 05:21 PM  
Super close macro?
Posted By Na Horuk
Replies: 58
Views: 4,585
You can use lens add-ons (apparently some are actually good, but cheap ones will ruin IQ. I hear good tings about Raynox? Something like that), you can attach a flipped lens (there are reversal rings for this), you can use extension tubes, you can use bellows (allow more flexibility than extension tubes).
But I cant imagine a 1:1 macro lens isnt good enough? I mean, plenty of lenses these days are marked as "macro" but they only go to 1:4 or 1:2. (even primes, not only zooms). Are you sure you are doing it right? For closest macro photography you need to set to MF and spin the focus to closest possible (as in, the other way from infinity) and then move your lens closer and closer until what you want is in focus. Can you maybe post "your best but not good enough" photo of this seed?
You might also want to consider just getting a microscope attachment or an enlarger lens (third-party), if this is not enough.
Forum: Photographic Technique 01-13-2013, 05:17 PM  
Super close macro?
Posted By Bob from Aus
Replies: 58
Views: 4,585
I almost never auto focus with macro, but then I am usually using flash. keep your subject still prefocus and move your own body/camera to get focused.

Going beyond 1:1 is always difficult and I have about 5 setups that I am unhappy with. I find the best result is with a good times 2 converter. I can't get the quality with any of my other setups.

As you have an aperture ring on your 100mm you can use a reversing ring. I don't have that option with my macros.
Forum: Photographic Technique 01-09-2013, 02:22 AM  
Astro Tracer (OGPS1) question
Posted By Stone G.
Replies: 4
Views: 2,851
HI LukeOB,

The trailing in itself indicates a failure in calibration. That can and will happen now and then for many reasons such as local magnetic disturbances, errors in reading of the focal length, changes in satellite positions........ But the kink in the trails could indicate that you have attempted to track the stars beyond the freedom of the sensor to move. I have had similar experiences myself.

I can see that you have taken the shot at 200mm FL and a 120s exposure so, what central star (declination) are we looking at?
Forum: Photographic Technique 01-08-2013, 11:42 PM  
Astro Tracer (OGPS1) question
Posted By LukeOB
Replies: 4
Views: 2,851
Greetings all, I am wondering if any Astro Tracer users have come across the following results - see attached pic (IMGP2705), which is a 2 minute exposure. I have had success so it's not that all images are looking like this - far from it, I think it is a fantastic addition to the kit, and it gets some nice "oohs" and "aahs" from the Canikon crowd :)

I am using the 70-200mm f2.8 from Tamron.

I have also uploaded a 60 second exposure of the Orion nebula to show that things are going right sometimes too! The mind boggles at what could be achieved with a longer lens...

Luke
Forum: Photographic Technique 01-13-2013, 03:26 PM  
Super close macro?
Posted By ChrisTrevino
Replies: 58
Views: 4,585
Yes you can use extension tubes, cheap ones won't let you AF though.

You could also flip the lens around and hold it up to the end of the camera and shoot through it reversed. Focus is a guessing game that way though as the viewfinder is pretty useless when you have to manually stop the lens down to like f/11-f/16 for a macro.
Forum: Photographic Technique 12-22-2012, 11:32 PM  
How do you color balance under LED?
Posted By JinDesu
Replies: 16
Views: 5,936
If I remember correctly, LED light is very specialized light in that it only puts out a small range of color. It makes white balancing very very difficult. The small range of color means that shifting the white balance cold or warm practically removes all light from the scene.
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