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Forum: Troubleshooting and Beginner Help 21 Hours Ago  
Lens focal length for use on bellows
Posted By Thagomizer
Replies: 15
Views: 319
The "right" focal length depends on the size of the object you're shooting, how much of it you're wanting to show, and at what size you want it to be. I often go to greater than 1:1 for full body shots of small insects or portrait shots of larger ones. At higher magnification, depth of field gets shallower and shallower, so the orientation of your subject with regards to the thin plane of focus becomes an important consideration.

You can also reverse the lens you're using on the bellows with an M42 reverse adapter ring. Most non-macro lenses 50mm and shorter perform better for macro work when they are reversed. References linked above have information on lens reversal. You're already going without automatic diaphragm with the bellows, so reversing the lens on the front standard isn't really costing you anything. With shorter focal length lenses reversed on extension, you never face the problem, noted above by photoptimist, of your focus point ending up inside the lens when they're mounted normally on extension. Your working distance will be the flange focal distance of the reversed lens you're using. With Pentax lenses for 35mm film or DSLR, that distance is about 45mm. Because you're mounting it via the filter threads rather than the lens mount, you can use any brand lens, as long as you've got the right combination of reverse adapter and stepping rings to fit.

Here's one of my go to links for macro ideas:

CHEAP MACRO -- Buying or exploiting a lens for ultraclose work - PentaxForums.com

Have fun, and if you feel so inclined, share your results.
Forum: Mini-Challenges, Games, and Photo Stories 5 Days Ago  
Thematic Seeing Red!
Posted By Thagomizer
Replies: 261
Views: 5,110
Watch that first step: it's a DOOZIE!
Forum: Pentax SLR Lens Discussion 5 Days Ago  
Macro lenses best for panorama stitching?
Posted By Thagomizer
Replies: 24
Views: 719
Forum: Mini-Challenges, Games, and Photo Stories 02-15-2020, 02:55 PM  
Game Song titles (or lyrics) illustrated
Posted By Thagomizer
Replies: 232
Views: 5,120
Thanks! I'm glad you're enjoying it. Thanks for contributing!
Forum: Mini-Challenges, Games, and Photo Stories 02-11-2020, 01:56 PM  
Thematic The Yard Birds Thread
Posted By Thagomizer
Replies: 1,772
Views: 112,437
Please do!
Forum: Mini-Challenges, Games, and Photo Stories 02-11-2020, 09:58 AM  
Show me a Sign! Billboards,sign,bus ads,shop signs go here!
Posted By Thagomizer
Replies: 5,449
Views: 426,385
So, 30 points for each one?
Forum: Non-Pentax Cameras: Canon, Nikon, etc. 02-11-2020, 09:00 AM  
Got Squirrel Shots? (In memorial of Rupert)
Posted By Thagomizer
Replies: 2,640
Views: 210,610
Perhaps if you were to dress as a large peanut...
Forum: Mini-Challenges, Games, and Photo Stories 02-11-2020, 08:54 AM  
Game Song titles (or lyrics) illustrated
Posted By Thagomizer
Replies: 232
Views: 5,120
Were you sitting on a cornflake when you took this one?
Forum: Mini-Challenges, Games, and Photo Stories 02-11-2020, 08:48 AM  
Thematic The Yard Birds Thread
Posted By Thagomizer
Replies: 1,772
Views: 112,437
Great series!
Forum: Mini-Challenges, Games, and Photo Stories 02-11-2020, 07:52 AM  
Thematic Good as Gold
Posted By Thagomizer
Replies: 211
Views: 4,415
I like the ghostly, indistinct reflections of the spectators in the side panels.
Forum: Pentax SLR Lens Discussion 02-05-2020, 01:23 PM  
Opinion time: what are your favorite manual lenses?
Posted By Thagomizer
Replies: 183
Views: 9,972
I've got one I'll have to play with more; I haven't really given it a good workout. It's a bit beat up; I had to replace the rubber grip on the zoom ring, but other than some abrasions on the finish, seems to be okay.
Forum: Lens Clubs 01-31-2020, 07:04 PM  
The Mirror Lens Club!
Posted By Thagomizer
Replies: 1,137
Views: 403,427
Yes, my 55BB behaves much better in bright sunlight.

The cardinal and bunny are quite good.
Forum: Mini-Challenges, Games, and Photo Stories 01-30-2020, 01:27 PM  
Thematic Look down, awaaay down...
Posted By Thagomizer
Replies: 250
Views: 6,066
tim-berrrr!!!
Forum: Pentax KP 01-30-2020, 09:15 AM  
Focus adjustment using Manual Lenses in U4 mode
Posted By Thagomizer
Replies: 9
Views: 455
You might find this article, posted a few days ago, helpful:Achieving Better Manual Focus with the Green Hexagon - PentaxForums.com
Forum: Pentax K-1 01-30-2020, 08:53 AM  
How bad of a thing is mirror flap?
Posted By Thagomizer
Replies: 13
Views: 638
I didn't know that! That's good information to have, thanks!
Forum: Lens Clubs 01-23-2020, 12:45 PM  
Macro by any means necessary club
Posted By Thagomizer
Replies: 540
Views: 107,713
I've never done any real testing on any of my many macro set-ups to see at what point diffraction becomes objectionable. What smaller aperture giveth in DOF, diffraction taketh away in clarity. At some aperture one reaches the point of diminishing returns. I'm guessing that point can vary from lens to lens (and photographer to photographer...). Focus stacking lets you use any given lens at its optimum aperture without regard to DOF, which is essentially synthesized in the stack. Those shooters like myself who are doing single shots instead of stacks have decide where that trade-off point between desired DOF gain and unacceptable diffraction loss is.
Forum: Lens Clubs 01-23-2020, 11:50 AM  
Macro by any means necessary club
Posted By Thagomizer
Replies: 540
Views: 107,713
Well that's good to know. I'm no optical expert; I'd rather understate than oversell. I'm happy to bring attention to the lens, and if it works better for stacking or other applications than I'm giving it credit for, so much the better (and shame on me!:D). I did notice the lack of CA, but I thought the sharpness wasn't quite there, and I thought that it could be diffraction rearing its ugly head. The thin depth of field might make whatever sharpness there is less obvious amidst the softness in front of and beyond the plane that is in focus. I certainly would be curious to see how it would work as a tool in a focus stacking rig. Unfortunately I don't have any stacking software, and my computer would probably choke to death on the throughput of data that would require.

I still have yet to try the 03 as the front element of a wide angle macro relay lens. I've got a selection of wide angle primes and zooms to use as the relay optic that, along with the right extension, will (with any luck) throw an image that gives APS-C coverage. I'm hoping that the 03 will offer better image quality than the cheap M12 board lenses I've seen used very effectively by others. We'll see what happens...
Forum: Pentax Q 01-23-2020, 10:21 AM  
Reversed 03 fish-eye on KP
Posted By Thagomizer
Replies: 14
Views: 800
More results from the reversed Q 03 fish-eye on my KP. I'm posting this on all three threads where I've been talking about this; "Reversed 03 fish-eye on KP", "Pentax Q mount macro reverse rings", and "Macro by any means necessary club."

Camera is tripod mounted on a focus rail. Electronic shutter with 12 second self timer for shooting, existing light using a diffused Ikea Jansjo light.

First some more "indutrial" targets. Printed number on a lens barrel:




Printing on a business card:





The edges of some small manilla envelopes:




Still industrial, but not mechanical. Multigrain bread...



and the surface of one of the seeds on the top of the bread.



Some closeup bug bits.

Our first subject, an unfortunate shield bug (?), which I found dead in a corner of the bedroom, under some stuff.

Here's the whole insect:



And a close-up of its eye:



Our second contestant is a cast-off cicada husk:



Some of its bits. The business end of one of its digging claws:



And spines at the (wrist? elbow??) joint of the same limb:



An adult cicada (found deceased).



A close-up of one of its eyes:



Because of the very limited depth of field, reversing the Q 03 fish-eye might best be used with flat subjects. More three dimensional subjects move out of the limited plane of focus very quickly in either direction; image quality is such that it might not be worth the trouble of stacking, though I'll let those who actually do focus stacking (of which I am not, as yet, one) decide this for themselves. I don't think this optic is a hidden gem that's going to take the photomacrography world by storm. That said, it is fun to play with and makes for a comparatively compact rig for high magnification shooting. If I'm feeling particularly optimistic (or masochistic) I might even try it in the field once weather is warmer.
Forum: Pentax Q 01-23-2020, 10:21 AM  
Pentax Q mount macro reverse rings
Posted By Thagomizer
Replies: 19
Views: 1,552
More results from the reversed Q 03 fish-eye on my KP. I'm posting this on all three threads where I've been talking about this; "Reversed 03 fish-eye on KP", "Pentax Q mount macro reverse rings", and "Macro by any means necessary club."

Camera is tripod mounted on a focus rail. Electronic shutter with 12 second self timer for shooting, existing light using a diffused Ikea Jansjo light.

First some more "indutrial" targets. Printed number on a lens barrel:




Printing on a business card:





The edges of some small manilla envelopes:




Still industrial, but not mechanical. Multigrain bread...



and the surface of one of the seeds on the top of the bread.



Some closeup bug bits.

Our first subject, an unfortunate shield bug (?), which I found dead in a corner of the bedroom, under some stuff.

Here's the whole insect:



And a close-up of its eye:



Our second contestant is a cast-off cicada husk:



Some of its bits. The business end of one of its digging claws:



And spines at the (wrist? elbow??) joint of the same limb:



An adult cicada (found deceased).



A close-up of one of its eyes:



Because of the very limited depth of field, reversing the Q 03 fish-eye might best be used with flat subjects. More three dimensional subjects move out of the limited plane of focus very quickly in either direction; image quality is such that it might not be worth the trouble of stacking, though I'll let those who actually do focus stacking (of which I am not, as yet, one) decide this for themselves. I don't think this optic is a hidden gem that's going to take the photomacrography world by storm. That said, it is fun to play with and makes for a comparatively compact rig for high magnification shooting. If I'm feeling particularly optimistic (or masochistic) I might even try it in the field once weather is warmer.
Forum: Lens Clubs 01-23-2020, 10:21 AM  
Macro by any means necessary club
Posted By Thagomizer
Replies: 540
Views: 107,713
More results from the reversed Q 03 fish-eye on my KP. I'm posting this on all three threads where I've been talking about this; "Reversed 03 fish-eye on KP", "Pentax Q mount macro reverse rings", and "Macro by any means necessary club."

Camera is tripod mounted on a focus rail. Electronic shutter with 12 second self timer for shooting, existing light using a diffused Ikea Jansjo light.

First some more "indutrial" targets. Printed number on a lens barrel:




Printing on a business card:





The edges of some small manilla envelopes:




Still industrial, but not mechanical. Multigrain bread...



and the surface of one of the seeds on the top of the bread.



Some closeup bug bits.

Our first subject, an unfortunate shield bug (?), which I found dead in a corner of the bedroom, under some stuff.

Here's the whole insect:



And a close-up of its eye:



Our second contestant is a cast-off cicada husk:



Some of its bits. The business end of one of its digging claws:



And spines at the (wrist? elbow??) joint of the same limb:



An adult cicada (found deceased).



A close-up of one of its eyes:



Because of the very limited depth of field, reversing the Q 03 fish-eye might best be used with flat subjects. More three dimensional subjects move out of the limited plane of focus very quickly in either direction; image quality is such that it might not be worth the trouble of stacking, though I'll let those who actually do focus stacking (of which I am not, as yet, one) decide this for themselves. I don't think this optic is a hidden gem that's going to take the photomacrography world by storm. That said, it is fun to play with and makes for a comparatively compact rig for high magnification shooting. If I'm feeling particularly optimistic (or masochistic) I might even try it in the field once weather is warmer.
Forum: Pentax Q 01-21-2020, 10:41 PM  
Pentax Q mount macro reverse rings
Posted By Thagomizer
Replies: 19
Views: 1,552
You're welcome! Certainly better than I expected as well. I'm going to be trying it with a set-up that includes a tripod, flash (or at least better light, probably my Ikea Jansjo) with diffusion, and a focus rail. I'll post my results here when I do.
Forum: Mini-Challenges, Games, and Photo Stories 01-21-2020, 06:39 PM  
Game Stupid Camera Tricks (and Stupid Lens Tricks)
Posted By Thagomizer
Replies: 156
Views: 8,609
Neat result from a happy accident!
Forum: Pentax Q 01-21-2020, 06:37 PM  
Reversed 03 fish-eye on KP
Posted By Thagomizer
Replies: 14
Views: 800
Thanks! Good information on dealing with the shutter/aperture. Similar to the workaround I've heard of for Canon EOS lenses.

I don't have a Q body, but it looks like a neat system. Thanks everyone for indulging this Pentax APS-C shooter's tinkering!
Forum: Pentax Q 01-21-2020, 06:15 PM  
Pentax Q mount macro reverse rings
Posted By Thagomizer
Replies: 19
Views: 1,552
I just discovered this thread. Cool item! I'm not a Q body shooter, but I've reversed a Q 03 fish-eye. Even though it lacks filter threads, I managed to mount it on my KP using a 37-49 step-up ring and a K-mount 49mm reverse adapter. I put a bit of masking tape around the front of the lens barrel for a snug fit in the 37mm end of the stepping ring.



There might be a combination of stepping rings that would let you mount it on a Q body using the Q mount reverse adapter which is the subject of this thread. No lens shutter or aperture to worry about, either.

I was pleasantly suprised with the results. This is a close-up of half-tone printing on a laser printed price tag:




I've put up a thread here on the Q forum here: Reversed 03 fish-eye on KP - PentaxForums.com
Forum: Pentax Q 01-21-2020, 05:43 PM  
Reversed 03 fish-eye on KP
Posted By Thagomizer
Replies: 14
Views: 800
Good to know. I thought it might be the case, as my reversed Kinotel 1 1/2 inch 8mm covers APS-c without extension, but I didn't know for sure.

I'm assuming like DSLR lenses without aperture rings that the Q 01 standard prime (and the rest of the Q lens line-up, excluding the toy lenses) stays closed when not mounted on a body? Without the mechanical linkage that can be wedged open, there would be no way (without a lot of slaving over a hot soldering iron to put together some means for communication) to get a larger aperture. I'm lucky the 03 doesn't have a diaphragm to worry about. The toy lenses, which I assume also have no diaphragm, would be darker still. Looks like I fell into the right optic!

I think the 03 as the front end of a wide angle macro relay rig is going to take a bit more experimentation...

---------- Post added 01-21-20 at 08:03 PM ----------

P.S. Just found this thread (pretty recent, too) on reversing Q lenses on Q bodies: Pentax Q mount macro reverse rings - PentaxForums.com
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