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Forum: Pentax K-1 & K-1 II 5 Days Ago  
Legacy Canon Lenses
Posted By Thagomizer
Replies: 10
Views: 495
If you can remove the optics of the adapter, it becomes a short extension tube. Of course infinity focus is no longer possible, and short focal length lenses are limited to macro distances. But telephoto lenses may still give you focusing abilities within a useful distance range. It depends on the thickness of the deglassed adapter and the focal length of the lens you're using on it. Another approach would be to find a set of completely manual third party extension tubes for both Pentax K and Canon FD. If they're both by the same manufacturer this is likely ideal. Take the thinnest PK ring and remove the mount intended to accept a PK lens. Replace it with the corresponding mount from one of the FD rings. It's possible, if they are made by the same manufacturer, that the screw holes from the FD mount will match the screwholes of the PK ring with the PK mount removed. This would save immensely on drilling and machining.

This approach should also work by replacing the camera end mount of an FD tube with a PK one; you're just doing the swap at the opposite end of the tube you're modifying. Again, choose whchever ring is thinnest. Mechanical linkages designed to allow aperture control from the camera body are no longer needed and my in fact interfere with the fit of the parts you're trying to put together. Removing them might help.

The thinner the ring the better, because it means you can focus farther out with any given lens than you'd be able to with a thicker ring.

I've not done this myself, so if you decide to try this out, you do so at your own risk.
Forum: Mini-Challenges, Games, and Photo Stories 08-14-2023, 08:36 AM  
Thematic The Yard Birds Thread
Posted By Thagomizer
Replies: 3,090
Views: 230,459
Hi all, it's been a while since I posted. Also a while since I've had something worth posting!

Here's an Osprey that perched right beside the bike path I take to work:













These are cropped from shots taken using my DA 55-300 ED, mostly not at 300mm. I found (as others have found) that results aren't as good at 300 as they are a little backed off.

Enjoy!
Forum: Troubleshooting and Beginner Help 04-17-2023, 01:36 PM  
Converting Nikon mount lenses to a Pentax M42 bellows bayonet
Posted By Thagomizer
Replies: 16
Views: 1,361
You might find the film era Nikon K series extension rings a source for project parts. The combine male and female Nikon F mounts with various lengths of extension tubes with 52mm threads. You can read more about them here: Extension Tubes - Nikon F2 Macro-photography
Forum: Pentax SLR Lens Discussion 02-12-2023, 09:29 AM  
Sigma 600mm F8 mirror vs. Pentax SMC 55-300mm ED
Posted By Thagomizer
Replies: 10
Views: 765
My own rules for shooting with mirrors are:

a) only shoot in good light and

b) make sure your subject fills the field of view.

Violating either of these rules usually results in disappointment.
Forum: Pentax SLR Lens Discussion 02-06-2023, 10:43 AM  
Fisheye adapter - who's used one?
Posted By Thagomizer
Replies: 6
Views: 732
I picked up a "Semi Fish Eye" to play with. I'm not where it is right now, and I don't recall the brand. On APSC I'm just losing the corners with a 35mm lens. Here's the original shot:



...and the cropped version:


Ready to Explode

I haven't used it much since my initial test drive, but It's pretty fun. You want to be careful that you don't overuse it, but with careful handling and the right subjects, it can provide striking results for not a lot ogf outlay. As I'm not ready to get an actual dedicated fish-eye lens, this will do for now.





Forum: Pentax SLR Lens Discussion 01-12-2023, 09:40 AM  
Physics behind Extension Tubes question
Posted By Thagomizer
Replies: 12
Views: 986
Indeed. Too much extension on too short a lens results in the focus point being inside the lens (which can let you see just how much dust you've got there!) With reversing a lens, you've always got the registration distance as working distance.
Forum: Mini-Challenges, Games, and Photo Stories 01-11-2023, 12:38 PM  
Game Stupid Camera Tricks (and Stupid Lens Tricks)
Posted By Thagomizer
Replies: 331
Views: 26,672
Forum: Pentax KP 01-11-2023, 12:30 PM  
KP settings for sharp tele lens pics.
Posted By Thagomizer
Replies: 17
Views: 2,379
Yes, that gannet shot is terrific! Surf's Wind's up!
Forum: Mini-Challenges, Games, and Photo Stories 01-11-2023, 12:25 PM  
Game Stupid Camera Tricks (and Stupid Lens Tricks)
Posted By Thagomizer
Replies: 331
Views: 26,672
Or, you've uncovered hyperdimensionality in cats; which I think would explain how they'll intently watch something that doesn't appear visible to us.

Of course your cat will now have to kill you. And anyone who's viewed this post. Secrets must be kept.
Forum: Pentax DSLR Discussion 01-01-2023, 09:11 PM  
Reverse lens macros
Posted By Thagomizer
Replies: 10
Views: 1,959
Reverse lens macro is challenging, but also a lot of fun.

Here are some of the results I've managed to get with:

DA 18-55 ALII kit lens 18-55 reversed macro | Flickr



DA 35 f2.4 Pentax DA 35mm f2.4 reversed macro | Flickr



Reversed 8mm movie lenses Reversed Kinotel Macro | Flickr



Unlike adding tubes (where too much extension on too short a lens results in the point of focus being inside the lens), you've always got a working distance equivalent to the registration distance of the lens being used. Not that that's a lot, but it's better than none!

I can vouch for the Raynox add-ons too. Some of the shots here were taken with a Raynox 250 added onto a Tamron 52BB 90mm macro: Tamron 52BB f2.5 macro, some with Raynox 250 | Flickr



...and on a Sigma 70mm EX DG f2.8 macro: Sigma EX DG 70mm f2.8 macro, some with Raynox 250 | Flickr



Links above are to albums with more examples. Enjoy!
Forum: Pentax KP 12-11-2022, 08:06 PM  
KP settings for sharp tele lens pics.
Posted By Thagomizer
Replies: 17
Views: 2,379
Be aware that when shooting with electronic shutter, while the shutter speed may nominally be 1/1000 of a second, the entire frame is not exposed at the same time. It's much like the travelling curtain of a film camera in which a narrow slit passes over the frame, so that each part of the frame gets 1/1000 sec. exposure, but only as the slit travels across that part of the film. The two shots below were taken with a mirror lens at 1/2000 sec. using ES, LV and wired remote. The branch the hawk was sitting on was moving up and down in the wind, stretching the bird in the first shot compared to the second:






If I recall correctly the "read speed"of ES is in the range of tenths of a second, essentially lengthening a shutter speed in the thousands of a second by a factor of approximately 100. That is to say that the very bottom of the frame will be exposed about 1/10 sec. after the top. I believe this is what causes what's known as "rolling shutter" in video. In subjects moving rapidly in the horizontal plane, this can give them a slanted or skewed look. The rotating blades of a fan or aircraft propellor can end up looking very strange indeed.


Here's a Forum discussion of MS vs ES:

Electronic Shutter (vs Mechanical shutter) questions - PentaxForums.com
Forum: Pentax SLR Lens Discussion 12-10-2022, 10:14 AM  
Budget vintage telephoto gems/interesting nature lenses
Posted By Thagomizer
Replies: 33
Views: 2,046
I've been very pleased with my results from the Tamron 55BB 500mm mirror. I try to avoid using it if a) there isn't a lot of light and b) I can't fill my frame with the subject. Violating either of these rules tends to get photos deleted. Maybe yours is a bum copy or, you weren't using the right mallet. Here are some of my images from this lens:

Mirror, mirror: Tamron 500mm | Flickr

Another vote for the DA 55-300. Mine is the non HD, non WR version. Here are shots from it:

Adventures with the DA55-300 Feb.24, 2020 | Flickr

Both are easiliy hand holdable and offer good close focusing capability.
Forum: General Talk 11-17-2022, 07:21 PM  
Steve, May you rest in peace
Posted By Thagomizer
Replies: 59
Views: 3,907
Steve's posts were always knowlegdable and encouraging. He enriched this forum, and its members, immeasurably. He will be missed.
Forum: Lens Clubs 11-16-2022, 02:42 PM  
Macro by any means necessary club
Posted By Thagomizer
Replies: 635
Views: 132,622
Yes, that's the case. It does eat up a bit of working distance, but it's an easier solution than jamming something against the lens's aperture control tab. An adapter with aperture control for mirrorless is going to use up more working distance, so going for an adapter intended for DSLR is going to be more convenient.
Forum: Lens Clubs 11-03-2022, 11:01 AM  
*Macro* lens club
Posted By Thagomizer
Replies: 5,102
Views: 682,703
I think I see something with a leg on the top left edge of rightmost mushroom?
Forum: Lens Clubs 10-23-2022, 07:22 AM  
Macro by any means necessary club
Posted By Thagomizer
Replies: 635
Views: 132,622
Thanks! Couldn't tell you what number. The ring on the adapter that lets me control the diaphragm indicates open and closed at either end of its throw. There are no click stops on the ring (or, obviously, the lens). I usually try to have it somewhere in the middle. I don't know what that numerical value would be, and have never bothered to try working it out. Could be f8-ish. As the 18-55 is lighter, more compact, and user friendly, I'm more likely to use it in this way than the 16-85.
Forum: Mini-Challenges, Games, and Photo Stories 10-19-2022, 12:53 PM  
Thematic Stupid Computer Tricks
Posted By Thagomizer
Replies: 185
Views: 12,274
Cool!. I've done some messing around combining high contrast B&W with oversaturated colour to give a comic book style look. I've probably posted these before, but what the hell.




Forum: Mini-Challenges, Games, and Photo Stories 10-19-2022, 12:40 PM  
Thematic =planes, trains, boats and automobiles=
Posted By Thagomizer
Replies: 6,841
Views: 512,984
Let's see.

Planes?





Check.

Trains?





Check.

Boats?










Check.

Automobiles?




Check!

Okay, what do I win?
Forum: Mini-Challenges, Games, and Photo Stories 10-19-2022, 12:03 PM  
Game Stupid Camera Tricks (and Stupid Lens Tricks)
Posted By Thagomizer
Replies: 331
Views: 26,672
Fall colours in motion.




Forum: Mini-Challenges, Games, and Photo Stories 10-19-2022, 12:00 PM  
Thematic Trees
Posted By Thagomizer
Replies: 5,926
Views: 393,491
Lots and lots of trees...

Agawa Canyon










Ten Mile Point, Manitoulin Island

Forum: Mini-Challenges, Games, and Photo Stories 10-19-2022, 11:55 AM  
Thematic Seeing Red!
Posted By Thagomizer
Replies: 507
Views: 21,701









Forum: Mini-Challenges, Games, and Photo Stories 10-18-2022, 07:21 AM  
Thematic Wetness...If the Subject is Water
Posted By Thagomizer
Replies: 2,262
Views: 181,890
That would be the Thousand Islands, at the eastern end of Lake Ontario. I've taken a cruise there, too! The 30,000 Islands is in Lake Huron, entirely in Canadian waters. Both are very scenic and picturesque. The 30,000 Islands are more wild and rugged, consisting of ancient rock with hardy, wind-sculpted trees clinging to them.
Forum: Mini-Challenges, Games, and Photo Stories 10-15-2022, 09:09 AM  
Thematic Stupid Computer Tricks
Posted By Thagomizer
Replies: 185
Views: 12,274
Some stitched panoramas from a recent trip to Northern Ontario:

Parry Sound:




Sudbury:




Agawa Canyon:
















Manitoulin Island:

Forum: Mini-Challenges, Games, and Photo Stories 10-15-2022, 09:00 AM  
Thematic Trees
Posted By Thagomizer
Replies: 5,926
Views: 393,491
Rock, trees, and sky, 30,000 Islands, Georgian Bay, Ontario.

Forum: Mini-Challenges, Games, and Photo Stories 10-15-2022, 08:57 AM  
Thematic Wetness...If the Subject is Water
Posted By Thagomizer
Replies: 2,262
Views: 181,890
Views taken on a cruise through a small part of the 30,000 Islands. Situated along the eastern shore of Georgian Bay, Lake Huron, it is the largest freshwater archipelago in the world.










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