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Showing results 1 to 25 of 30 Search: Liked Posts
Forum: Troubleshooting and Beginner Help 12-26-2016, 12:06 AM  
F number relativity
Posted By GUB
Replies: 26
Views: 2,597
Just one thing in regards to your OP that I don't think anyone has touched on so far ; If you used any focal length lens and moved forward or back so the subject was the same size on the sensor then at any given f-stop the depth of field would be the same for all lenses.
That is -- For all lenses,
For a given format (apsc),
At a given subject magnification ,
At a given f-stop ,
Dof would be the same .
Of course your background changes with the change in perspective.
Nice portraits on your link.
Forum: Troubleshooting and Beginner Help 12-25-2016, 12:42 AM  
F number relativity
Posted By clackers
Replies: 26
Views: 2,597
You're sayin' all the right things, Stein, so fingers crossed for some nice keepers, you deserve them!
Forum: Troubleshooting and Beginner Help 12-24-2016, 10:21 PM  
F number relativity
Posted By lithedreamer
Replies: 26
Views: 2,597
Let's see...

Q1: These lenses will be quite different if both are wide-open. F4 to F2.8 is a whole stop, and on a full-frame camera, it will show on your depth of field (on APS-C, too, but more so on 35mm). The newer lens will be better controlled for various aberrations, sometimes this comes across as a 'clinical' rendering. I'm not familiar with the 100mm M, but they're both Macro lenses, so you should expect fairly sharp images from wide-open, some might say too sharp.

Q2: If it's this lens:

Tamron 70-300mm F4-5.6 AF Di LD Macro Lens Reviews - Tamron Lenses - Pentax Lens Review Database

It seems to get mixed reviews. I wouldn't feel great paying a model and shooting with it.
Forum: Post Your Photos! 10-18-2016, 09:05 PM  
Macro DIY F-Stop Tube Macro 7.1# (Specially Test MAMIYA/SEKOR M42. Lens)
Posted By Mahaku
Replies: 0
Views: 1,059
Continues From DIY F-Stop Tube Macro 7# (Specially Test MAMIYA/SEKOR M42. Lens)

Spider in flower.


https://www.pentaxforums.com/forums/177-macro-photography/331652-tip-technic-...ube-macro.html



















Forum: Pentax K-1 & K-1 II 09-10-2016, 12:59 PM  
Too much noise on K-1
Posted By gerardbaron
Replies: 50
Views: 9,525
Photos Taken with Live View
No corrections


Look at the first left bud
Forum: Pentax SLR Lens Discussion 08-16-2016, 04:09 PM  
Well, I've Had Enough
Posted By Adam
Replies: 78
Views: 8,443
Yup, those old SDM lenses are desperately in need of an upgrade. They can't compare to the modern DC ones. With that in mind, I don't see any reason not to get the Sigma 17-50mm (at $399 even) unless you want the weather sealing.
Forum: Troubleshooting and Beginner Help 08-10-2016, 07:00 PM  
Astrophotography with K-3 II (how-to)
Posted By gifthorse
Replies: 5
Views: 7,984
The next few nights should be a good time for some night photography. The Perseid meteor shower peaks, depending on who you listen to, on Wednesday night/Thursday morning or Thursday night/Friday morning. The shower will run through the weekend but the peak will be over the next few days. Best viewing (and photography) will be from about midnight to just before sunrise. Have fresh batteries and plenty of them. Set up in a dark place. The darker, the better. Set the camera on a tripod and point it toward the northeast sky. A lot of sky will increase the odds of a meteor appearing in a frame but you'll want something, building, low mountains, ground on the bottom of the frame for some context. Turn off the noise reduction, both long exposure and high iso. Initial setting try 1600 iso, aperture maybe two stops from wide open, and if you're using a 50mm lens, a shutter speed of about 8 seconds. If you're using a shorter focal length you can add a little time to the exposure. If you're using a longer focal length, you'll need to subtract some time from the exposure to avoid star trails. Check the image and adjust until you get an exposure you're happy with. When you're satisfied with the image, put the lens cover on and take an exposure. This is your dark frame you'll use it later. Anytime you change exposure length or iso, you'll need a dark frame for that exposure. When you are all set up, set the intervalometer to take a picture at an interval slightly longer than the exposure length. If you are making 8 second exposure, set the camera to take a picture every 10 seconds. You can do the math to figure how long you want to shoot. At ten second intervals, you'll get 6 shots per minute 60, you'll take 360 images in an hour. The object here is to have maximum open shutter time. After you're done shooting you can look up "dark frame subtraction" in an internet search to learn how to use dark frames instead of in camera noise reduction. Once you're comfortable and equipped for night shooting, post processing will greatly improve your images. but that can come later. You can also use the GPS very effectively here, but the foreground will blur. I'm not going to try to cover everything here but I hope to get you out night shooting with as much success as possible. There are too many types of night photography to cover here and each has its own techniques and equipment need. Astrophotography, night landscape, constellation, meteors, etc. and I don't know just what equipment you have. It's a whole other world out there at night. So, this should get you going for the next few nights with minimum gear. Good luck!
Forum: Pentax DSLR Discussion 08-04-2016, 09:02 AM  
I know , I know, counting likes is bogus but..... the K-1 is doing well.
Posted By normhead
Replies: 27
Views: 2,665
For me, retired and all, and weak Canadian dollar where it is, the K-1 is out of my price range. So I see K-1 users the same way I used to see D800 users. Out of my class. There could come a time when a K-1 would be a possibility, but right now a K-70 interests me more. And a lot of that has to do with what percentage of my yearly income it will take to purchase it. Plus my K-3 still works great.

But I was also just thinking this is Pentax turning the corner in a lot of ways.

I always said the biggest thing with the D800 was you could spend a lot more on lenses if you wanted to. It's getting to be that way with Pentax. The best ring motors are on the FF lenses that cost more than the APS-c lens for the same FoV. The only really advanced lens with KAF4 is the new 55-300. I mean really? It's a great consumer lens, but I'm not trading my SDM 60-250, or DA*200 ƒ2.8 for it. So while I'm happy for all you dudes with lots of disposable income, for me the K-1 stuff is about as relevant to me as the D800 stuff was 5 years ago. What it has done is, most of the new lenses coming out will be FF. All the long glass is very expensive, and I'm in the position a lot of Nikon D7000 users were 5 years ago. All the new stuff coming out is geared for the FF cameras.

The thing I liked about Pentax was their best efforts went towards gear I could afford. That's no longer the case.

One difference is that buying a D800 would have meant starting all over again with lenses. Eventually buying a K-1 will make better use of the lenses I own. With the phasing out of SDM lenses and screw drive lenses, Pentax equipment prices will go through the roof. I'd suggest anyone in my position to get what they want now. I know the redone DA*-200 will have a fast focusing PLM motor and KAF4 aperture control, but I won't be able to afford it. My choice is an SDM 200mm I can afford, rather than wait for a KAF4 PLM 200 that I can't afford. I'm sure there are a lot of others in my position. The K-1 sounds like a great thing.... but it's just not a practical thing. My big purchase this year was a $900 CAD DA*200. And even that meant KD for dinner for a while. I suspect there are a lot more folks in my shoes than there are who can just snap up a K-1.

So while I'm happy to see the resurgence of interest in Pentax, the K-1 doesn't change much for me. I'm the kind of guy that if I needed a K-1 I would have bought a D800 5 years ago, I wouldn't have waited until now.
Forum: Pentax DSLR Discussion 08-02-2016, 06:29 AM  
Are we really THAT rare?
Posted By totsmuyco
Replies: 7,240
Views: 985,572
One of the reasons I chose Pentax is the k-mount. After a long rest from photography for about 15 years, I bought my first digital camera which was an Olympus e-410. A year later, I bought my e-30, and more accessories. About 3 years later, Olympus just killed the 4/3 mount. Such a short lived system. So my question is why shouldn't I buy a system that has supported its mount since the beginning? I believe that this is a firm commitment from Pentax and that's something I like. Photography is an expensive hobby. One who goes into it must be able to grow into the system and not let you throw your money into something that will just be given a quick death. I guess some companies don't really care about their customers. This creates disgusted customers and does not create brand loyalty. Olympus have great lenses maybe even better than the rest but, I will never be wooed by that again. As I have always said, as long as Pentax will support the k-mount, it is where I'll stay.
Forum: Pentax News and Rumors 07-07-2016, 04:59 PM  
Detailed specs of Pentax K-70
Posted By reh321
Replies: 423
Views: 55,621
Thank you.
Now we do agree {except I put zero value on video}
Forum: Pentax DSLR Discussion 06-29-2016, 02:53 AM  
Upgrade to K-3II and what next?
Posted By D1N0
Replies: 13
Views: 1,597
Well ask your daughter what she wants. (keep both probably ;).
Forum: General Talk 06-21-2016, 08:51 PM  
Can You Help Out A Fellow Pentaxian Who Is Down On His Luck?
Posted By seacapt
Replies: 6
Views: 1,467
Original message deleted. Thanks to all who participated!
Forum: General Photography 06-13-2016, 12:13 PM  
SD cards can survive a lot...
Posted By bertwert
Replies: 5
Views: 1,196
Apparently they can even survived being swallowed and passed through a digestive system with the contents still recoverable...
I Swallowed a 64GB microSD Card
Forum: Post Your Photos! 06-12-2016, 02:52 AM  
Nature Tried going all Lars Van De Goor...and it all went wrong!
Posted By Kerrowdown
Replies: 19
Views: 1,802
I know now where your going wrong... your not using a Hasselblad for your imagery like Lars Van De Goor does. ;)

You'll get instantly the same picture results when you do, no problem. :D

:lol::lol::lol:
Forum: Pentax Forums Giveaways 06-11-2016, 06:27 PM  
Win a Sandisk Extreme Pro 64Gb card: flash giveaway!
Posted By a5m
Replies: 124
Views: 8,958
This kind of stuff is what makes this forum and Pentax unique. I can't see myself not using a Pentax :).
Forum: Pentax DSLR Discussion 05-26-2016, 05:29 AM  
Are we really THAT rare?
Posted By aT0Mx
Replies: 7,240
Views: 985,572
So we're rare yes, but I do hate when we are all "exclusive like".


I was just banned from a flickr group because I use (and have used) non Pentax cameras. (I also don't keep all exif data because I do edit my photos) I will keep with Pentax always, but I also just got a Canon t3i for free, sort of, and will use it for time lapses.


I would like to just say Go Pentax! But boo exclusivity.
Forum: Troubleshooting and Beginner Help 05-15-2016, 01:51 AM  
Focal length (crop factor) confusion
Posted By PJ1
Replies: 9
Views: 1,398
No. A 90mm lens is always a 90mm lens. What changes is the angle of view. For example, a 50mm lens made for FF (e.g. the FA 50/1.4) produces an image circle which will cover a FF sensor. Put that same lens on an APS-C body and APS-C sensor is only 2/3 the size (width and height) of the FF sensor. You are cropping the image when you use the lens with a smaller sensor. You could say that the rest of the image circle is going to waste, but that is what is meant by the 1.5 crop factor. In rough terms, the 50mm lens on an APS-C sensor is giving you the same angle of view as a 75mm lens on a FF sensor. But it is still a 50mm lens.
Forum: Troubleshooting and Beginner Help 05-15-2016, 01:49 AM  
Focal length (crop factor) confusion
Posted By Adam
Replies: 9
Views: 1,398
No, it's 90mm on both. Forget what format the lens is designed for- focal length never ever changes, as it's an optical property of the lens :)



Again, the focal length is just 50mm per the logic above. (off topic, but the DA 50mm does work just fine on full-frame too)



Kind of...but "acts as" and "converted" aren't a good way to think about it. The real reason things are the way they are is because the APS-C sensor sees less of the frame than the full frame sensor. Hence, each format has a different field of view with the same lens.

The 50mm has a focal length of 50mm on APS-C and 50mm on full frame.
The 90mm has a focal length of 90mm on APS-C and 90mm on full frame.

The 50mm on APS-C gives the same field of view as a 75mm lens would on full frame.
The 90mm on APS-C gives the same field of view as a 135mm would on full frame.

The 50mm on full frame gives the same field of view as a ~33mm lens would on APS-C.
The 90mm on full frame gives the same field of view as a 60mm lens would on APS-C.
















You Tube




Hope this clears things up. See also:
The Crop Factor Explained: An Animation - Tutorial Videos | PentaxForums.com
Forum: Troubleshooting and Beginner Help 05-15-2016, 05:01 AM  
Focal length (crop factor) confusion
Posted By Schraubstock
Replies: 9
Views: 1,398
Ha, I removed the lens, had a good look around inside the mirrorbox but couldn't find anything :confused::confused::confused:
Forum: Pentax DSLR Discussion 05-09-2016, 10:01 AM  
Are we really THAT rare?
Posted By AggieDad
Replies: 7,240
Views: 985,572
When I'm asked about my Pentax, I generally respond with, "Yeah, you won't find one of these at BestBuy." Then I give their camera a meaningful look. 😜
Forum: Monthly Photo Contests 05-05-2016, 06:20 PM  
Night Light
Posted By JoseFF
Replies: 1
Views: 644
Deserves to be nominated, doesn´t it?
Forum: Troubleshooting and Beginner Help 03-14-2016, 11:05 AM  
How can I tell it's enough?
Posted By normhead
Replies: 50
Views: 6,938
What joke?.. it's a description of what happened in my house! I buy the Tamron 90, my wife steals it. ( I hardly ever get to use it anymore, it's always mounted on her camera.) She decides she only likes primes, she won't use her Sigma 18-250 anymore. She'd rather shoot with the Tamron 90 with the 1.7 or 1.4 TC on than use a zoom. Sooner or later I have to get her either the DA* 200 or DA*300. She whines "I don't have anything long to shoot with.", the same way she whines when she thinks she needs a new pair of jeans. I got that Tamron 90 for $250 second hand, but it's going to cost me a lot more than that.

It is dark... but it's not a joke. It's a crying shame. :D
Forum: Pentax Camera and Field Accessories 03-11-2016, 07:17 AM  
does this bag exist?
Posted By Heie
Replies: 36
Views: 4,934
ahem...yea...what they said...

PETAPIXEL - I Left My Camera Bag on a Train

-
Heie
Forum: Site Suggestions and Help 03-09-2016, 03:14 PM  
Question PF logo on my image, just curious what that means.
Posted By Adam
Replies: 18
Views: 1,735
Probably because you saw the image on google, where it would show up with a watermark. If you hit control+F5 in that thread, the watermark should disappear.

We added watermarks to hotlinked images (images embedded on other sites but hosted on PF) as other forums/blogs were occasionally hotlinking our members' photos without attribution, which I don't think is fair to anyone who contributes here.
Forum: Troubleshooting and Beginner Help 02-28-2016, 08:49 AM  
How can I tell it's enough?
Posted By Rupert
Replies: 50
Views: 6,938
Lookin' down your way, it does look pretty dark and gloomy down there.:( Otis advises that if you will PM him a shipping address he will send you a crate of squirrels to perk things up. He guarantees your boredom will end quickly!:lol:

IMGP0056-800 by James Williams, on Flickr

Otis Disclaimer: Not responsible for care, feeding or housing for shipped squirrels. Not responsible for destruction of property, injury or death caused by said squirrels. In layman's terms.......You are on your own! :D
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