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12-17-2012, 11:40 AM   #16
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My 100mm f3.5 is razor sharp at macro or telephoto. It's actually one of my very favorite lenses. It was tied with the 50mm f1.7, until I got my K-01. Now the Tamron is coming out a lot more, because it is actually focusing accurately. (Has front focus issues on my K-x body, so I haven't used it in a long time).

Charles.

12-17-2012, 05:14 PM   #17
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QuoteOriginally posted by ChopperCharles Quote
My 100mm f3.5 is razor sharp at macro or telephoto. It's actually one of my very favorite lenses. It was tied with the 50mm f1.7, until I got my K-01. Now the Tamron is coming out a lot more, because it is actually focusing accurately. (Has front focus issues on my K-x body, so I haven't used it in a long time).

Charles.
I think your M100 is going to be killer on the Q. When I was testing my D FA 100 WR this past weekend, I quickly thought of the Vivitar 105 Macro lens I had just sold recently. The focus throw on it was so long it would have been a treat to focus on the Q.

I also thought of my Tamron mirror lens which I had also sold - it should be fun to test - looking forward to your results with all your lenses once you get started. It's addictive!
12-17-2012, 09:23 PM   #18
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What is a telecompressor?

Charles.
12-17-2012, 09:51 PM   #19
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A telecompressor looks like a teleconverter but works backwards. It demagnifies making the lens a shorter focal length, but the lens becomes brighter! The trade off is the image circle thrown by the lens is smaller. Using FF lenses on the Q solves the problem. The image circle is still much larger than the Q sensor.
thanks
barondla

12-18-2012, 05:04 AM   #20
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Hrm. Where can one get a k mount telecompressor?

Charles.
12-18-2012, 05:41 AM   #21
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QuoteOriginally posted by ChopperCharles Quote
Hrm. Where can one get a k mount telecompressor?
Astronomy supply companies. They are also called "focal reducers."
You might have to do some "adapting" to get one to fit the pentax K-mount...
12-18-2012, 07:11 AM   #22
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Pentax could seriously mess with canikon if they brought out a 1.5 or 2X focal reducer in Q/PK mount. Photographers aren't used to making a lens brighter. Camera companies "took" the teleconverter from telescope manufacturers years ago. Why not the telecompressor?. Ackk, even more cool stuff I would need for my Q. Don't do it yet Pentax. I need to catch up from the last batch of products.
thanks
barondla
12-18-2012, 09:15 PM   #23
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It would be interesting to see if a well-designed telecompressor could actually increase quality and sharpness of lenses. Teleconverter spreads the light out, but a compressor focuses the beam more tightly. Which is also why you gain a stop instead of losing a stop. I'd be very interested to see my 100mm f3.5 macro suddenly become an f2.8 just by attaching it to a compressor on the Q...

Charles.

12-18-2012, 09:50 PM - 1 Like   #24
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QuoteOriginally posted by barondla Quote
Pentax could seriously mess with canikon if they brought out a 1.5 or 2X focal reducer in Q/PK mount. Photographers aren't used to making a lens brighter. Camera companies "took" the teleconverter from telescope manufacturers years ago. Why not the telecompressor?. Ackk, even more cool stuff I would need for my Q. Don't do it yet Pentax. I need to catch up from the last batch of products.
This is really a good idea!!! With the Q's extreme crop factor, a compressor would be useful to pull back the FOV, and if it made lenses faster as a bonus. . . wow

Another great lens accessory idea would be a Q 1.7x or even a 1.4x or 1.2x Auto Focusing Adapter. Since they were the only mfg to really successfully do this for 35mm, if they could make one that worked with the Q it would be a coup. All the user would need to do is get the focus close manually, and the AFA would automatically take over to gain critical focus -- and it would work with any lens that you could adapt to the Q.

. . . and how about an Auto Focus Telecompressor Adapter. . .

Scott
12-19-2012, 01:22 PM   #25
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QuoteOriginally posted by snostorm Quote
. . . and how about an Auto Focus Telecompressor Adapter. . .
Yes, please. That!

A nice 0.5x AFA built into a Q-K adapter (with aperture control, leaf shutter and ND filter, of course) would be pretty amazing, to say the least.

How would (theoretically) this change diffraction and DOF? Could a 100mm Macro be stopped down a bit more? Hmmm...
12-20-2012, 08:41 AM   #26
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Also, my lens isn't an M100, it's a Promaster AF 100mm f3.5 Macro. The non-SMC coated version of the Pentax 100mm f3.5 Macro.

Pentax version: SMC Pentax-FA 100mm F3.5 Macro Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database

There doesn't seem to be a pic of the Promaster version in the database, but it's the same lens.

Charles.
12-20-2012, 09:00 AM   #27
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QuoteOriginally posted by barondla Quote
A telecompressor looks like a teleconverter but works backwards. It demagnifies making the lens a shorter focal length, but the lens becomes brighter! The trade off is the image circle thrown by the lens is smaller. Using FF lenses on the Q solves the problem. The image circle is still much larger than the Q sensor.
thanks
If I took the elements out of a 2x teleconverter, flipped them around in position and direction, then reinstalled them, would I have a telecompressor?
12-21-2012, 07:35 AM   #28
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Good question. Don't know the correct answer. That migt work. I remember a 2X converter that the optics popped out to make an extension tube. Hmmmm.
thanks
barondla
12-21-2012, 11:55 AM   #29
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So, got my adapter and tried my 50mm f1.7... it's okay. Soft wide open, reasonably sharp at f4. But the 40mm XS is razor sharp even wide open! Holy cow that's a nice combination!

My 100mm macro with the matched 1:1 adapter is freaking amazing too. I need a lot of good light, but it's able to see every little bit of dust and crap accumulated in the grooves of a record. VERY nice. I even attached my 500mm f8 mirror, and on an overcast day was able to see some amazing zoom... but without a tripod actually getting a shot that's not blurry was a trial. This weekend I'm going to try all of my lenses, find a nice target, and take sample photos.

I have DOF now...

Charles.
12-21-2012, 11:58 AM   #30
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Fotodiox (or whatever) adapter seems well made. It's solid metal, and the inside is painted black already. It's perhaps not as flat as it could be, but it's not silver or anything, which is what I expected after I read about people painting theirs.

The only issue i have with it is that the Q-mount is a little loose. The camera can move ever so slightly on the end of the adapter. That's a little annoying, but it doesn't seem to effect anything. Is there a way to tighten it up?

Charles.
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