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02-17-2017, 08:32 AM   #16
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QuoteOriginally posted by Twevor Quote
I just got the adapter from SRS Microsystems in the UK and asked about the tripod mount. They had one left, but said they could get them from Pentax. Cost of the mount was 39, and was marked up as the 38100 Pentax Tripod Mount for DA*300. It came retail boxed as an accessory.
Ricoh Imaging doesn't list it on the US page anymore, but when it was it cost $90. It can be imported from a Japanese seller for less than $40...

02-17-2017, 09:55 AM   #17
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QuoteOriginally posted by barondla Quote
That is the aftermarket adapter. Thanks for the assist Heinrich Lohmann! Hope they still supply these.
Thanks
barondla
The tripod foot is readily available from Japan:
Genuine Pentax Tripod Mount For K-Mount & Adapter Q 38100 | eBay

---------- Post added 02-17-17 at 12:05 PM ----------

I've used the genuine K->Q adapter, but the leaf shutter causes vignetting with tele lenses. There's no way to turn off the leaf shutter unless you go with a speed > 1/1000 that I'm aware of.
I reserve it now for macro where I want to synch the flash at daylight speeds ..
So I've been using my genuine "Pentax KC Adapter" coupled to a regular C->Q adapter. It's well made, no wobble. There is no tripod attachment however.
This way the Q uses only the electronic shutter which does not vignette and zero vibration.

This is the adapter for those interested, it was made in the 80s or 90s for video and cine cameras to allow use of K lenses:
Pentax KC Adapter | SMC PENTAX 1:1.8/55 +Pentax KC Adapter f? | Flickr
These pop up from time to time on eBay for less than $30, although there is one now at a much higher price:
Rare Pentax KC K to Cine Adapter (1014-9) | eBay

Just another option if you don't need the leaf shutter (for flash synch) that you could also use with any other cam that takes a standard C mount adapter!
02-17-2017, 10:36 AM   #18
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QuoteOriginally posted by kayakfari Quote
The tripod foot is readily available from Japan:
Genuine Pentax Tripod Mount For K-Mount & Adapter Q 38100 | eBay

---------- Post added 02-17-17 at 12:05 PM ----------

I've used the genuine K->Q adapter, but the leaf shutter causes vignetting with tele lenses. There's no way to turn off the leaf shutter unless you go with a speed > 1/1000 that I'm aware of.
I reserve it now for macro where I want to synch the flash at daylight speeds ..
So I've been using my genuine "Pentax KC Adapter" coupled to a regular C->Q adapter. It's well made, no wobble. There is no tripod attachment however.
This way the Q uses only the electronic shutter which does not vignette and zero vibration.

This is the adapter for those interested, it was made in the 80s or 90s for video and cine cameras to allow use of K lenses:
Pentax KC Adapter | SMC PENTAX 1:1.8/55 +Pentax KC Adapter f? | Flickr
These pop up from time to time on eBay for less than $30, although there is one now at a much higher price:
Rare Pentax KC K to Cine Adapter (1014-9) | eBay

Just another option if you don't need the leaf shutter (for flash synch) that you could also use with any other cam that takes a standard C mount adapter!
The only time I use my Genuine Pentax adapter is with my Sigma 70-300mm lens - typically towards the long end; I've never noticed vignetting with it. Originally I was using a Genuine Chinese adapter, but then I started wondering whether the rolling shutter could cause slight blurring, because it takes the electronic shutter 1/15-th second to do a complete scan even at 1/1000-th second "shutter speed", so there could be slight issue between lines, and that is the reason I switched to the Genuine Pentax one.
02-17-2017, 11:37 AM   #19
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QuoteOriginally posted by reh321 Quote
The only time I use my Genuine Pentax adapter is with my Sigma 70-300mm lens - typically towards the long end; I've never noticed vignetting with it. Originally I was using a Genuine Chinese adapter, but then I started wondering whether the rolling shutter could cause slight blurring, because it takes the electronic shutter 1/15-th second to do a complete scan even at 1/1000-th second "shutter speed", so there could be slight issue between lines, and that is the reason I switched to the Genuine Pentax one.
The vignetting I've experienced is with 500mm (Tamron mirror) and the 1000/8 refractor. I think it just as result of how a leaf shutter works at high speeds (500, 1000).
Sometimes I get a rolling shutter effect with a skewed image, but most of the time I trigger with an IR remote. At these kinds of effective focal lenghts (2800 and 5600 or even 11200 with a TC) it's pretty much for stationary subjects.

02-17-2017, 01:46 PM   #20
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QuoteOriginally posted by kayakfari Quote
I've used the genuine K->Q adapter, but the leaf shutter causes vignetting with tele lenses. There's no way to turn off the leaf shutter unless you go with a speed > 1/1000 that I'm aware of.

To take the last issue first: On my Q10 I only have the choice (in Custom Menu item 13) between electronic shutter disabled or electronic and leaf shutter both enabled at the same time. On the other hand, my Q-S1 gives me three options (in Custom Menu item 1): Electronic shutter only, Leaf shutter only or both enabled at the same time.


The second issue with vignetting with tele lenses, I don't understand. I have never experienced that to any noticeable degree, at least as I find it. Here are some test shots with my Q10 and the Pentax Q adapter for K-mount lens:


Pentax Q10 with Pentax DFA 100mm f/2.8 lens



Pentax Q10 with Tamron Adaptall-2 SP 80-200mm f/2.8 (Model 30A) at 200mm



Pentax Q10 with Pentax DA* 200mm f/2.8 lens



Pentax Q10 with Tamron Adaptall-2 SP 350mm f/5.6 (Model 06B) mirror lens.
02-17-2017, 01:53 PM   #21
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QuoteOriginally posted by Stone G. Quote
To take the last issue first:my Q-S1 gives me three options (in Custom Menu item 1): Electronic shutter only, Leaf shutter only or both enabled at the same time.
Yep, the Q7 has those three options also...
02-19-2017, 05:16 PM   #22
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QuoteOriginally posted by BigMackCam Quote
Yep, the Q7 has those three options also...
On my original flavor Q, I have only two options: Enable, Disable.
All this does is allow shutter speeds shorter than 1/1000 with the electronic shutter when enabled. At speeds longer than 1/1000 it will always use the leaf shutter, when attached.
So unfortunately with the original Q the leaf shutter can not be disabled.

As far as the vignetting, I actually posted a thread about it on 05-1-2015: (before I lost access to that account)
Pentax Adapter Q for K Mount Lens vignetting at faster speeds - PentaxForums.com

This was my conclusion which I double checked. Lenses ranged from 300/2.8, 400/4.5 up to 1000/8 and 500/8 reflex:

"I was able to compare mine with another brand new genuine K->Q adapter and the results were the same. The effect is mostly visible at 1/800 -1/1000 and with high contrast settings (like Bold Monchrome) on the Q.
I conclude that it's in the nature of the leaf shutter at such a high speed, and 1/1000 is very fast for a shutter of this type.
If anybody wants to try, compare 1/1000 vs 1/1250 at which point only the electronic shutter is used.
You will see that there is uneven illumination causing a sort of hot spot in the center."

Just FYI. I don't use the genuine adapter with the super tele lenses.
02-22-2017, 02:07 PM   #23
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Adapters

I have both the Fotodiox Q to K and a Pixco Q to K adapters, the latter having a tripod mount, which is useful and even though it doesn't have a rotation ring, doesn't bother me much, as I tend to use 1:1 ratio in telephoto format (Something to do with shooting 6x6 film for years )
The Pixco version, seems to fit on both lens and body a little better and capture better images.
My biggest issue is that Pentax only produce Q to PK and not other lens mounts, so I'm stuck with "dumb/blind" adapters for my Zeiss Sonnar T and Leica lenses, which is great shame.

03-13-2017, 10:56 AM   #24
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QuoteOriginally posted by reh321 Quote
The only time I use my Genuine Pentax adapter is with my Sigma 70-300mm lens - typically towards the long end; I've never noticed vignetting with it. Originally I was using a Genuine Chinese adapter, but then I started wondering whether the rolling shutter could cause slight blurring, because it takes the electronic shutter 1/15-th second to do a complete scan even at 1/1000-th second "shutter speed", so there could be slight issue between lines, and that is the reason I switched to the Genuine Pentax one.

That's kind of disappointing and extremely slow in my opinion, guessing that problem exhibits itself in the non-shuttered Q lens.

If it was more suited for adaptability seems like it would be more popular. Also curious why a much larger sensor doesn't exhibit the same problem with such a slow roll with adapted lens.

Also how does that work with flash sync then? Since you can sync to a much higher speed than the mechanical shutter-in-lens, but if it actually takes 1/15-th of a second to scan the whole sensor surface, part of the sensor would be blacked out because it lasted longer than the flash duration.

I have a Fotodiox PK and Adaptall adapter coming (already have the Leica Thread mount one in hand), always had good luck with them on micro-4/3rd, but that's a different beast all together it seems.
03-13-2017, 01:44 PM   #25
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QuoteOriginally posted by kb244 Quote
That's kind of disappointing and extremely slow in my opinion, guessing that problem exhibits itself in the non-shuttered Q lens.

If it was more suited for adaptability seems like it would be more popular. Also curious why a much larger sensor doesn't exhibit the same problem with such a slow roll with adapted lens.
Most cameras have a "focal-plane" shutter which comes just before the sensor; that kind of shutter can exhibit exactly the same phenomenon, but faster motion is needed in order for it to occur.

Personally, I prefer the leaf shutter, because it is so very quiet. Sometimes I am asked to take pictures during our church service, and I use the Q-7 because people are totally oblivious to its whisper-quiet shutter - nothing at all like the clatter-clack of a focal plane shutter. The one downside of the leaf-shutter is that the rolling-shutter issues can arise with any adapter or lens if the adapter/lens doesn't provide a shutter, and only Pentax does provide a shutter right now {since the shutters are provided by Copal, I'm guessing anyone could incorporate a shutter into their adapter ... but that would add at least $100 to the cost of the product, and most non-OEM manufacturers seem to be in a race to bottom price}.

incidentally - you see exactly this same problem with video cameras. Last night we were watching a documentary about JFK Jr,; when they showed video shot by someone who had flown with him, I commented I was fairly sure the propeller was actually straight - its apparent curvature was another artifact of rolling shutter.
03-13-2017, 01:52 PM   #26
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I am familiar with a rolling shutter, but in video where a mechanical shutter is not used it doesn't exhibit that problem so much on my olympus or Panasonic.

But I am aware of the mechanical shutter placed in front of the sensor in most normal situations, had one permanently lock up.

Far as leaf shutters go, yes they tend to be quiet and their biggest advantage is flash sync all speed, disadvantages traditionally has been slower top shutter speeds (usually no more than 1/500) pretty much the same shutter styles found in TLRs or the 4x5 view cameras we use at school. I just wasn't aware until recently that some of the lens had their own shutters to counter the drawbacks of the sensor.
04-23-2017, 01:00 PM - 1 Like   #27
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The rolling shutter when using long 135mm or longer lenses does add softness in images due to camera movement during the long sensor read times. The SR can't help with this only the Pentax adapter can solve the softness problem. I have found quite a visual increase in sharpness when using the Pentax adapter with shutter
05-15-2017, 03:14 AM - 1 Like   #28
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I recently picked up the Fotodiox D mount adapter for old 8mm movie camera, it is very fun to use! You can find the Keystone 8mm cameras for around $10 to $20 on the ShopGoodWill auction site. Another great reason to have a Q! :-)
05-15-2017, 04:35 AM - 2 Likes   #29
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QuoteOriginally posted by kayakfari Quote
As far as the vignetting, I actually posted a thread about it on 05-1-2015: (before I lost access to that account)
Pentax Adapter Q for K Mount Lens vignetting at faster speeds - PentaxForums.com

This was my conclusion which I double checked. Lenses ranged from 300/2.8, 400/4.5 up to 1000/8 and 500/8 reflex:

"I was able to compare mine with another brand new genuine K->Q adapter and the results were the same. The effect is mostly visible at 1/800 -1/1000 and with high contrast settings (like Bold Monchrome) on the Q.
I conclude that it's in the nature of the leaf shutter at such a high speed, and 1/1000 is very fast for a shutter of this type.
If anybody wants to try, compare 1/1000 vs 1/1250 at which point only the electronic shutter is used.
You will see that there is uneven illumination causing a sort of hot spot in the center."

Just FYI. I don't use the genuine adapter with the super tele lenses.
Here's a quote from Wikipedia:
"Ideally the shutter opens instantaneously, remains open as long as required, and closes instantaneously. This is essentially the case at slower speeds, but as speeds approach their maximum the shutter is far from fully open for a significant part of the exposure time. Effectively the shutter acts as an additional aperture, and may, for example, cause vignetting or increase depth of field, undesirable if shallow focus is being used creatively."

This problem is usually minimized by placing the shutter within the lens assembly, near the optical center of the lens, where the bundle of rays is at its narrowest (central shutter). But in the Pentax adapter, the shutter is located behind the lens, thus exacerbating the issue. The vignetting becomes visible when combining fast shutter speeds with long focal lenses, which are more image-space telecentric.

Cheers!

Abbazz
05-21-2017, 03:58 PM   #30
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That's it, I knew I wasn't crazy. Thanks Abbazz!
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