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06-13-2014, 04:31 AM   #1
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Longest exposure 2 sec for non-Q lenses?

I was really dissappointed to discover slowest shutter speed is 2 seconds for manual lenses. I am using Q, firmware v 1.13. It is supposed to be so?

06-13-2014, 05:12 AM   #2
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Unless you have the Pentax brand adaptor, the slowest shutter speed setting is 2 seconds. The Pentax adaptor has a leaf shutter, like the Q lenses, so it can be left open for long exp. But without it, there is no shutter, it's electronic.

Last edited by Kendigitize; 06-13-2014 at 09:04 AM.
06-13-2014, 05:23 AM   #3
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I am talking about the SLOWEST shutter speed. I don't see any reason why it would be restricted.
Moreover, even without Pentax leaf shutter adaptor electronic rolling shutter can do 1/4000s, it's mainly X-sync which is improved.
06-13-2014, 07:18 AM   #4
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QuoteOriginally posted by alliumnsk Quote
I am talking about the SLOWEST shutter speed. I don't see any reason why it would be restricted.
Moreover, even without Pentax leaf shutter adaptor electronic rolling shutter can do 1/4000s, it's mainly X-sync which is improved.
Well, he said it...because it's an electronic shutter if you don't use the Pentax adapter.

06-13-2014, 09:09 AM   #5
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Question . . . is the Pentax adapter worth the $200+?
06-13-2014, 11:27 AM   #6
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I think it depends on what you want to do or like to shoot pix of and what lens you want to match with it. I'm saving up for one because I want the longer than 2 sec exp. time for astro photography, and I take pix of birds so a 2500mm lens (depending on the lens used with it) would come in handy. The ability to use the cameras built ND filter, fast flash speeds for humming birds in flight, etc. are what make it worth the $$ for me.
06-13-2014, 11:34 AM   #7
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QuoteOriginally posted by TonyTurley Quote
Question . . . is the Pentax adapter worth the $200+?
Hi Tony,

The advantages I've found over the inexpensive 3rd party adapters are:

1. Elimination of rolling shutter ("jello") effect.*
2. ability to sync pop up flash to 1/2000, and compatible external flash up to 1/250.*
3. Increased slow shutter speed to 30 sec (?) -- IIRC -- don't usually shoot very long shutter speeds.*
4. Much finer aperture control.
5. Relatively large area to attach a compatible tripod ring to the adapter
6. Much more robust build quality. I'm not including the expensive Novoflex nor the one that's only available in Japan (can't remember the brand offhand) in this comment as I assume excellent build quality from these. I have only the RJ and the Fotodiox to compare to the Pentax.

*These are due to the presence of a leaf shutter in the Pentax K 2 Q adapter.

For me, the advantages of the mechanical leaf shutter justify the cost. I need the faster sync speed to shoot macros in daylight with flash. 1/13 sync is in this type of shooting is just not doable. I've not experienced a lot of jello effect in what I shoot, but many here have experienced this.

Is it worth the $200 -- for me it is. YMMV. . . I'd suggest that you start off with one of the 3rd party adapters. If and when you run into one of the limitations, then you can more easily decide if it will be worthwhile to pop for the Pentax version.

Scott
06-13-2014, 11:59 AM   #8
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Can anyone explain why X-sync with external flashes still 1/250? What Pentax engineers were smoking?
Also the problem with adapter not only price, but what about manual lenses available in m39 or canon, nikon mounts? (at least m42-k adaptor exists)

---------- Post added 06-14-14 at 02:00 AM ----------

QuoteOriginally posted by Kendigitize Quote
The ability to use the cameras built ND filter, fast flash speeds for humming birds in flight, etc. are what make it worth the $$ for me.
does adapter have ND filter too? The camera body obviously lacks it.

---------- Post added 06-14-14 at 02:15 AM ----------

QuoteOriginally posted by Kendigitize Quote
Unless you have the Pentax brand adaptor, the slowest shutter speed setting is 2 seconds. The Pentax adaptor has a leaf shutter, like the Q lenses, so it can be left open for long exp. But without it, there is no shutter, it's electronic.
Did Pentax say something why is that?

06-13-2014, 02:14 PM   #9
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Thanks for the information, Ken & Scott. I think for now I'll stick with the Fotodiox adapter, until and unless I run upon any limitations. My primary nightime camera has been a Sony NEX-5R, which is fabulous for astrophotography.
06-13-2014, 06:09 PM   #10
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QuoteOriginally posted by alliumnsk Quote
Can anyone explain why X-sync with external flashes still 1/250? What Pentax engineers were smoking?
Also the problem with adapter not only price, but what about manual lenses available in m39 or canon, nikon mounts? (at least m42-k adaptor exists)
Who knows? Maybe a software/hardware limitation of the flashes? All my old leaf shutter cameras got full sync speeds. Though remember that all modern Pentax flashes are made for DSLRs.

QuoteOriginally posted by alliumnsk Quote
---------- Post added 06-14-14 at 02:00 AM ----------
QuoteOriginally posted by alliumnsk Quote
does adapter have ND filter too? The camera body obviously lacks it.

---------- Post added 06-14-14 at 02:15 AM ----------

No it doesn't, they are lens bound.

QuoteOriginally posted by alliumnsk Quote
Did Pentax say something why is that?
I'm just speculating but maybe the electronic shutter gets worse with heat and therefor gets the limitation. Or the sensor may be designed that way for a reason. It could also only be a software thing and a limit to promote the official lenses but I find it improbable with some official lenses lacking shutters.
06-14-2014, 06:45 AM   #11
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QuoteOriginally posted by alliumnsk Quote
I was really dissappointed to discover slowest shutter speed is 2 seconds for manual lenses. I am using Q, firmware v 1.13. It is supposed to be so?
One way around the 2 sec. limitation is to use multi exposure mode with Auto EV adjustment, you could chose 5 exposures of 2 sec. each and combine them automatically in camera to get a 10 sec. exposure or more if you chose all with a lens without a shutter
06-16-2014, 09:55 AM   #12
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QuoteOriginally posted by alliumnsk Quote
Can anyone explain why X-sync with external flashes still 1/250? What Pentax engineers were smoking?
This is because of a hardware issue. Pentax external flashes are designed to work with Pentax DSLRs, which have two-curtain focal plane shutters. With the mechanical curtain shutters on Pentax DSLRs, the maximum shutter speed at which the entire sensor is exposed at once is 1/250 of a second. At shutter speeds higher than this, the trailing curtain begins to close before the leading curtain fully opens. That makes it so the fastest shutter sync you can achieve with a conventional single firing of a strobe is 1/250 of a second. To achieve sync speeds higher than this the strobe flashes more than once, each time when different parts of the frame are exposed. This will only work on a Pentax DSLR with a P-TTL flash. When using generic flashes or remote flashes, you will generally be restricted to the 1/250 of a second sync speed.

The Q uses a leaf shutter, which operates differently than a two-curtain focal plane shutter, so the higher sync speed settings on Pentax flashes will not work with it. Therefore, the 1/250 of a second sync speed is the highest one that will work.

I don't know what the maximum shutter speed is at which the entire frame is exposed with the leaf shutter on the Q. If it's higher than 1/250 (which I suspect it may be), then it's possible that a special flash made for the Q might be able to achieve a higher sync speed. In fact, there must be some way to achieve a higher speed because the built in flash can sync at up to 1/2000 of a second.

I believe that 1/250 is a pretty standard maximum sync speed for two-curtain focal plane shutters. Cameras that attain a higher sync speed either use the same trick as P-TTL flashes with Pentax DSLRs or use a different kind of shutter.

Last edited by CFWhitman; 06-16-2014 at 01:36 PM.
06-18-2014, 12:47 PM - 1 Like   #13
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You can get external flashes to fire in optical slave mode while using the Q onboard flash as a master at the 1/2000 sync speed if you do so with native lenses 01/02/06 (and I suspect 08 but I don't have one to test.)

---------- Post added 06-18-14 at 12:49 PM ----------

QuoteOriginally posted by Kendigitize Quote
I think it depends on what you want to do or like to shoot pix of and what lens you want to match with it. I'm saving up for one because I want the longer than 2 sec exp. time for astro photography, and I take pix of birds so a 2500mm lens (depending on the lens used with it) would come in handy. The ability to use the cameras built ND filter, fast flash speeds for humming birds in flight, etc. are what make it worth the $$ for me.
Please note the ND filters are in the native lenses, not the body, so you will not get that feature with the OEM adapter.
08-06-2014, 03:47 AM   #14
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QuoteOriginally posted by crewl1 Quote
You can get external flashes to fire in optical slave mode while using the Q onboard flash as a master at the 1/2000 sync speed if you do so with native lenses 01/02/06 (and I suspect 08 but I don't have one to test.)[COLOR="Silver"]
Thanks! That option might come in handy sometime.
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