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03-02-2017, 11:50 AM   #1
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IQ with adapted lenses?

I am a big Q fan and have Q Q10 and Q 7 bodies along with 02 06 08 and 01 lenses and am always amazed at the quality and tone of images the system can achieve.
However with adapted lenses utilising photodiox and Pixcon adapters I achieve very mixed results. I have a Carl Zeiss T Sonnar 85mm F2.8 and SMC Takumar 135mm F2.5, both quality glass that have very clean optics.
The problem I tend to have, is that there is often a smoky blue or milky cast to the images, which can also be obvious in live view on screen.
After playing around with the WB I can often improve tone and IQ.
Is this caused by using the cameras shutter and not utilising the Pentax adapter with leaf shutter? I don't mind buying the proper adapter, despite the high costs, but I couldn't then utilize other brands, like Leica and Zeiss?
I should add, this occurs on all three bodies.
Any views please?

03-02-2017, 02:24 PM - 1 Like   #2
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I have the Pentax Q adapter and have tried our many lenses of varying focal lengts. Based upon my experiences, I fell pretty safe when I say that the leaf shutter will not solve your issues. With adapted lenses one shuold take into account that

A) Resolution as we would normally perceive it is measured in lines per image height and the 1/2.3" and 1/1.7" sensors of our Qs are actually much more demanding in that respect than an APS-C, let alone an FF sensor. Your Q lenses have been specifically designed for the small sensor format.

B) Your 85 and 135mm lenses effectively serve as very long telephoto lenses on a Q and thus, more sensitive to atmospheric haze and turbulence. Rather than playing with the WB, you should probably try to enhance contrast and clarity using Curves and Levels in the developing/post-processing of your images.
03-02-2017, 03:01 PM   #3
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Q lens

I will put a few images up when I get time, strangely the brighter the conditions the less the smoky effect is, so could be down to a higher shutter speed.
I achieve pretty sharp images, they just seem to have a strange hue. Even at very close distances the same effect occurs, so it's not down to atmospheric conditions. I will continue to play with the settings. Thanks for the advice
03-02-2017, 03:27 PM - 1 Like   #4
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Pixel Hunter, I had one of the very first Fotodiox Q>PK adapters. The image quality was inferior to the Pentax made adapter that followed later. There was a loss of contrast and a smokey blue look to images. Looking at the adapter, told part of the story. The interior was the same shiny black as the exterior. Bad idea!

To fix the adapter, I painted the inside with flat black paint. This improved the iq considerably. Better contrast, less blue shift, etc. Took another adapter and added sticky backed black felt flocking material internally. This provided even better IQ.

Purchased the Pentax made adapter when it came out. It is amazingly over designed and built. Pentax knew the light beam from adapted lenses was much larger than the Q sensor. All that extra light bouncing around inside a camera isn't good. Pentax uses multiple stray light control measures. There is felt flocking, flat black paint, ridges, and light baffles. This adapter even outperformed my felt flocked adapter.

The Pentax leaf shutter also allows proper capture of moving subjects without distortion and high flash sync shutter speeds.

The aftermarket adapter companies improved their products by painting with flat black paint. The newer your adapter, the better. I would still spend a few $ and flock it.

Everything else mentioned by Stone G is true. A Q crop factor pushes lens performance unbelievably hard. Shoot test shots at different apertures to find the optimum performance. We can't do much with a turbulent atmosphere.

Hope this helps
barondla

03-02-2017, 03:31 PM   #5
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Hi Pixel,
I recognise your description which can also be put as " low contrast".
I have made home brew machined adaptors from Pentax -M to m43 which is not as stringent as your case with the smaller sensor.
Two suggestions:

1) The adaptor needs to have an emissivity in the bore approaching unity. The best practical way i found to do that,
was to use adhesive backed telescope flocking - the astro guys use that.

2) If you refer to SMC Takumar (Bayonet) 135mm F2.5, then according to my tests,
( I have 2 of them) they are by far the worst lenses in my Pentax -M collection.
They exhibit unacceptably low contrast and flare from light.

I hope you resolve your problem.
03-02-2017, 04:29 PM - 1 Like   #6
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I agree with all Barondla said. Internal reflections are even more noticeable in smaller 'tubes' because the tighter tube walls have a higher percentage of the total light path. Killing reflections has been a common item in the Q adapter experience.

Using an adapted bellows extension opens up the 'tunnel' noticeably.
03-02-2017, 11:41 PM   #7
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All interesting input thanks, both adapters have a stepped machined interior with a coarse finish that is painted Matt black. I guessed this is to kill internal stray light reflections. Aperture seems to make little difference, to the effect.
The Sonnar T lenses have a very high reputation, so was expecting an improvement over the Takumar 2.5. But seems similar.
Tuning the WB seems to improve things, as does prevailing light. Bright Sun seems to remove much of the blue haze.
07-10-2017, 04:25 PM   #8
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Good info.

07-10-2017, 04:40 PM   #9
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You might try using longer lens hoods. I use a Pentax 135mm hood on my 50mm SMC and it seems to help. Quality cine lenses usually need a deep hood as well.
07-10-2017, 06:17 PM - 1 Like   #10
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Ricoh Rikenon 25/1.4 8 mm film projector lens, very short FFD, macro-only. Handheld against PQ/C adapter with threaded plate removed (using bayonet part only).

On Q7
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Last edited by murrayatuptown; 07-10-2017 at 06:59 PM.
07-10-2017, 06:24 PM - 2 Likes   #11
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Kodak Anastigmat 35/3.5 odd threaded/retaining ring mount, supposedly from a 16mm Cine aviation machine gun camera, wide open, handheld on reversed retaining ring on PQ/D adapter. I think it's a triplet. Aperture is round wide open (hex if stopped down).
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07-10-2017, 06:34 PM   #12
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Kodak Anastigmat (Cine 16 camera) 38/2.5, uncoated, S or M mount homebrew adapted

Finally, after 1.5 years, I am using a tripod!

Silkipix-post-processed (uncoated lens and other factors produced lowish contrast).

Should I post the pre-processed images, or doesn't that matter?

I just noticed the Cine-Ektanon 38/2.5 that I also have, DOES have a coating icon (the circled L indicating "Lumenized"), and this lens (Anastigmat) does not.

I don't have a way to track what my manual lens f-stops are. When I change lenses, I try to power-cycle the camera and enter the new focal length for the IS. I enter the f.l. in mm and a decimal number indicating the last digit of the lens marking f-# (EXIF data for this appears as FL = 38.5). This helps me on a given day when I avoid using two 38/2.5 lenses, import the images and name the folder with the lens name before shooting with a similar lens that I could not otherwise distinguish. I still don't know how to track the f-stop selected short of a notebook, and I'm not dedicated enough to do that.

I did shoot some sequences of f/2.5, 4, 5.6, 8, 11, 16 and 22 at same ISO, allowing camera to adjust shutter speed. Those I can figure out which f-stop is which because I took notes on those.

On Q7.
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Last edited by murrayatuptown; 07-10-2017 at 07:01 PM.
07-10-2017, 06:58 PM   #13
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Kodak Cine-Ektanon (16 mm Cine camera) 38/2.5 coated (Lumenized)

No tripod on these, I ran them through same Silkpix default setup I used for the lower-contrast images...I've just learned to live with them.

On Q7.

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Last edited by murrayatuptown; 07-10-2017 at 07:13 PM.
07-10-2017, 07:17 PM   #14
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Pic of the 35/3.5 Kodak Anastigmat 16 Cine gun cam lens

A previous mounting method. C-mount threaded tube in PQ/C adapter, lens just sits in the tube, held in place with fingers.
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07-12-2017, 06:04 PM - 1 Like   #15
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Keystone 20/1.3 projection lens on Q7

This lens has always been hard to figure out spacing for, the FFD is so short.

It has a stepped rear tube profile, and today I realized inserting the narrowest back section through a PQ/D adapter is reasonably close enough some macro focus is attainable...Focus is then achieved by shuffling back & forth with the tripod while holding the lens against the PQ/D mount, or tilting the tripod, (which doesn't go well for me...having occasional vertigo!).

Hard to use, but an achievement of sorts...I'd had it roughly a year and had not figured out a way to use it.

I've not seen (or looked, yet) D-mount extension tubes, but I have used C-mount extension tubes as coarse helicoids...better than the usual junkyard mounts I try to achieve.

You can find a lot of flaws with this lens...it's very hard to get much DOF, it probably has a bunch of CA, but the images are so busy, I'm not sure which flaw is which...kind of fun to play around with. Projection lenses have been hit or miss for me...not using a tripod in the past didn't help.
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