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Forum: Pentax Full Frame 2 Days Ago  
K-2 Wishlist
Posted By Class A
Replies: 46
Views: 2,499
I'd like to see the option of delaying the Pixel Shift shot sequence, i.e., introduce longer pauses between them, and let the camera trigger flashes/strobes for each shot individually.

Pixel Shift lends itself for product shots or other static indoor scenes. However, it currently forces one to use continuous lighting. It would be awesome, if people could use their flash/strobe gear instead with the camera allowing for enough time for recycling.

If longer pauses between the individual shots are not conducive to actually capturing different colour information for each sensel position then at least the flash/strobe triggering should be enabled. Workarounds like using very low light levels or group cycling could be used to avoid recycling issues nevertheless.
Forum: Pentax K-1 2 Days Ago  
1:1 Crop Mode Speeds?
Posted By Class A
Replies: 22
Views: 784
Not sure what any of that has to do with what I wrote. :)


Well, it does omit the masked pixel data from original PEF files, for instance.
(Most people don't need that masked pixel data anyhow, but it part of the original data that is filtered out by the Adobe DNG converter.)

If that kind of data reduction occurs, I think it is plausible that only visible pixels (those inside the 1:1 mask) could be actually stored in the DNG file (still not demosaiced, of course).


I won't be doing any experiment myself because I shot about three square images with my K-1, mainly for testing purposes. :)

I just thought I mention the potential for someone who shoots a lot of 1:1 images and is keen on saving data to check whether the Adobe DNG converter may do the trick for them. TBH, I doubt the converter would go through the trouble of filtering the data but it is not entirely inconceivable that it does.
Forum: Pentax K-1 3 Days Ago  
1:1 Crop Mode Speeds?
Posted By Class A
Replies: 22
Views: 784
Storing only the data of the 1:1 content isn't predicated on special sensor read-out support.

In other words, while a sensor read-out speed increase would not be possible without a dedicated read-out mode, it is very much possible to only write the 1:1 content to the card.

I'm wondering whether a conversion to a DNG file, e.g., using the Adobe DNG converter and a Pentax PEF file as input, could achieve the file size reduction some are after. The question is whether the resultant DNG file will still contain all of the RAW data and the mask specification, or just the relevant RAW data.
Forum: Photographic Industry and Professionals 3 Days Ago  
Rant: camera prices and quality per format
Posted By Class A
Replies: 184
Views: 5,059
No, he hasn't.

You appear to be overestimating the influence of the ISO setting on noise.
The reason why higher ISO settings appear to correlate with higher noise levels is that one typically raises the ISO setting when light levels are low. The lower light levels available to high-ISO captures are what primarily leads to higher noise levels.

Please see photoptimist's post about what the main source of noise in digital images nowadays is. The stochastic nature of light itself typically causes more noise than the image capturing technology.

If you had the choice between taking an image at ISO 100 and or at ISO 200 with the latter option having double the amount of photons available to form the image, say by increasing the illumination level (without any overexposure occurring in either case), which situation would you prefer?

Hint: The noise-reducing effect of more photons (total light) trumps any potential minor increase of the conversion noise floor implied by the ISO setting increase. A number of modern sensors are referred to as being essentially "ISO-less" because their performance does not depend on the ISO setting. Pretty much the same overall image noise is observable whether the shot is taken at, say ISO 800 or at ISO 100 and then pushed by three stops in post production. In other words, the ISO 800 image doesn't show any noise that has been introduced by the high ISO setting as such, but just the noise that was already present in the ISO 100 image.

P. S.: Ian used the correct equivalent ISO 400 setting.
Forum: Travel, Events, and Groups 3 Days Ago  
Kiwi Pentaxians
Posted By Class A
Replies: 16,508
Views: 1,080,636
True, the K-1 received a number of firmware updates that even introduced new features but that was at a time when it wasn't an "old model" yet.


Yes, let's hope the K-3 successor will give us something to discuss.
It seems a foregone conclusion that the AF system has been considerably revised. At the very least, there will be a lot more frame coverage than it used to be the case for Pentax APS-C cameras.

Let's hope they improved video capabilities as well.
I'm not sure why they even bother to add microphone input and headphone output to their current cameras, given the otherwise mediocre support for video.


The connection to video is the desire to support AF during video recording. The latter only really works well with OSPDAF. At least some OSPDAF implementations give rise to both striping and banding. I'm not sure the K-70 actually avoids these issues, I rather suspect it hasn't come under enough scrutiny. I'm not sure, though.

Panasonic's DFD system avoids the OSPDAF limitations and seems to be improving but isn't as good yet and may never be.


All good! :)
Forum: Pentax Forums Giveaways 4 Days Ago  
Sticky: PentaxForums 100 Year Giveaway - November- General Raffle Entry Thread
Posted By Class A
Replies: 320
Views: 4,793
Count me in. :)
Forum: Travel, Events, and Groups 4 Days Ago  
Kiwi Pentaxians
Posted By Class A
Replies: 16,508
Views: 1,080,636
Sure, I get that.

On the other hand, how much "in a pinch" compromise is one ready to accept?

As Joe McNally once said (I'm paraphrasing): "Direct flash = no picture".
Sure, you can take a shot with a pop-up flash on the camera. Will it result in a picture worth having? In almost all instances the answer is "no", if you want to maintain certain standards.

Same with audio, a built-in microphone could work in a pinch, but in how many videos would you really want to incorporate sound recorded in such a manner?

While in-body sensor stabilisation can achieve very good results, if the rest of your footage uses a gimbal, I'm pretty sure the difference will be noticeable.



The regular speed footage was very stable as well, though. I don't think he wanted to oversell the gimbal. It's a comedy channel and I watch his videos mainly for the entertainment factor. He makes good points about technical details now and then but that's a secondary (and unreliable :) ) aspect of his videos.

Part of the motivation for my post was to get some of you to chuckle about this guy. :) While he recently turned more into a "review" channel because he has been discovered by manufacturers as a potential promotion vehicle and I feel that the entertainment factor has suffered from him trying to do the stretch between being funny and giving the product a fair deal at the same time, I think he is still very funny at times. His older videos are funnier, though, IMHO.

The other motivation was to point out that there appear to be pretty compact gimbal options out there that you may not have been aware about. I thought you might appreciate hearing about such options. Apparently not. :)


So it seems that adding in-body stabilisation on its own wouldn't be really useful then.


I have to say I lack empathy for those who buy a tool and expect it to be usable for something which it wasn't primarily designed for. If they don't check in advance of the purchase whether the tool is capable to meet their requirements for this secondary function then they have no right to be surprised/disappointed just because "It's ".

DPReview and others are trying to sell us the idea that every camera for stills photography needs to be useful for video as well.
I dispute that assumption and decidedly reject the notion of compromising on stills photography just to optimise the secondary use case.

Video cameras have different requirements and hence require different decisions regarding ergonomics, extensibility, interfaces to accessories, etc. It is OK when a stills photography camera gives one some video as a by-product -- Pentax once said about the K-7 video capabilities that they essentially just made it possible to record the LiveView feed -- but it doesn't make sense to expect getting a great video camera as well as a great stills photography camera without having to pay for it somehow.

Nowadays when "good video" appears to imply a soul-destroying (slight exaggeration here :)) viewfinder experience, striping, and banding, I'm not in favour of inflicting all these downsides on photographers, just because there are companies that see a revenue/profit optimisation opportunity in selling compromise tools, rather than speciality products.

Even just making it more expensive for stills photographers to buy equipment because the hardware is designed to handle video as well is objectionable to me.
I'm aware of the argument that supporting video as well is thought to drive up sales numbers which results in a better mass production price/cost ratio. However, that assumes the video part is competitive with alternative offerings. In case it isn't, it could be better to increase the attractiveness of a camera (in terms of reduced price) for people that don't care about video in the first place.

I'm sure there are other cameras for still photography, say from Phase One and Hasselblad that are not very good at doubling as video cameras.
If people don't take issue with these cameras "being incomplete" why would Pentax cameras be expected to follow Sony's lead that assumes that every photographer is also a videographer?

I get that you are a hybrid user and I think anyone in your category has every right to want good video performance as well as good stills photography performance. I just object to the idea purported by DPReview and others that it is implausible for any camera to largely neglect video as it suggests that there aren't customers who want a camera that provides uncompromised stills photography performance.


While I hope that the K-3 replacement will be convincing in the video department, I also hope that it won't use OSPDAF.

I don't think Pentax cameras should attempt to beat Sony / Panasonic cameras at their game.
Ricoh wouldn't succeed in the first place and they would just destroy the unique selling proposition they have left at the moment.
In my view, as soon as Ricoh will turn Pentax cameras into "also-rans" competing with the hybrids from Sony/Panasonic, etc., it will be the start of the end.

I'm not saying that Ricoh should neglect video performance but that they should try to achieve it without compromising stills photography, e.g., by using hybrid viewfinders, instead of EVFs, or using a DFD AF approach, rather than OSPDAF, plus they shouldn't increase the price for a stills photography camera just because good video requires the use of more expensive hardware components or additional expenses for video codec licenses or whatever. :)
Forum: Photographic Industry and Professionals 5 Days Ago  
Rant: camera prices and quality per format
Posted By Class A
Replies: 184
Views: 5,059
  1. Images with static content exist. Images with dynamic content exist as well. In the latter case one wants the motion blur to be the same. Hope that makes sense. However, the is a more fundamental reason than desiring the same level of motion blur which is:

  2. The shot taken at 1/1000s will use more photons than the shot taken at 1/2000s (everything else being equal). The mountains may look the same in terms of their shape but when you want to push shadow areas, you'll be more successful with the 1/1000s shot.



Whether you call it "exposure" or "total light" doesn't matter for what you "see".

With any given image you look at, you can convert "exposure" into "total light" and vice versa.

Also, there is no "insistence" on total light. It is just useful to realise that it is the total photon count that matters for image noise, whereas "exposure" is only useful to know when you also know the sensor size. In other words, if you only know the exposure but not the sensor size, you cannot make any prediction about the image noise. In contrast, if you know the total number of photons used to produce the image, you can predict the image noise without even having to know how big the sensor is.

That's why "total light" is a useful concept (in addition to making it easy to understand the relationship between shooting parameters and image properties).
Forum: Photographic Industry and Professionals 6 Days Ago  
Rant: camera prices and quality per format
Posted By Class A
Replies: 184
Views: 5,059
Very good point.

The entrance pupil can only be equated with the size of the iris if the lens elements in front of the iris achieve a magnification of factor one, or don't exist at all. :)
Forum: Travel, Events, and Groups 6 Days Ago  
Kiwi Pentaxians
Posted By Class A
Replies: 16,508
Views: 1,080,636
Thanks for sharing the comparison.

The DxO-processed image looks cleaner but also more "digital". Some areas seem over-smoothed and over-sharpened, particularly in the close ups.
I find that the other image has a more organic look to it and could be improved by changing the WB a bit.

All a matter of taste of course and in the full images the DxO artefacts aren't problematic; also different levels of adjustment would probably produce a less over-processed (in my view) looking image.
Forum: Travel, Events, and Groups 6 Days Ago  
Kiwi Pentaxians
Posted By Class A
Replies: 16,508
Views: 1,080,636
@richandfleur
I think you should forget about in-body stabilisation for video and embrace the idea of using a small gimbal like the "Weebill S".
















You Tube



Forum: Photographic Industry and Professionals 6 Days Ago  
Rant: camera prices and quality per format
Posted By Class A
Replies: 184
Views: 5,059
Are you reading my posts at all?

I already explained that if you keep the pixel size constant than "more pixels" automatically translate into "larger sensor".

Can we agree on simple facts like this one?



The "Print" tab isn't any less "real".


What is "dumb" about that?

Your statement is equivalent to saying "If you double the distance between a light and a subject, you only get a fourth of the light on the subject. It's as dumb as that.".

Perhaps "as simple as that" applies. However, what is "dumb" about laws of nature?


They don't need to.

Why would they expend the effort when one can calculate the outcome?

If they actually printed an 8x12 image and measured it, they would only confirm the numbers that they already obtained by calculation.

Why do you think that the ability to calculate the effect makes the effect less real?

There is no good reason whatsoever to discredit a phenomenon purely on the basis that there is a numerical way to predict its magnitude.

If you actually went through the exercise of printing two images with the output size, coming from two cameras with different sensor sizes, you could see for yourself that all the predictions/calculations are accurate. When using the same f-stop, the DOF from the larger sensor camera will be shallower and the noise levels will be lower.

This real effect maps to a calculation based on the number of pixels in an image because we are assuming that the pixel size is constant. So if a camera has two times the amount of pixels, its sensor area is two times as large.

This of course does not mean that you could observe the same effect when comparing sensors with the same size where one just happens to have a higher pixel pitch, i.e., more but smaller pixels. The noise advantages that can be computed from reducing a certain amount of pixels to a standard 8MP format only materialise if the pixel sizes are constant. I trust you already know why that is.

I hope this helps.
Forum: Photographic Industry and Professionals 6 Days Ago  
Rant: camera prices and quality per format
Posted By Class A
Replies: 184
Views: 5,059
I must admit that I indeed didn't watch the video.

I trusted that despite their reputation for being pretty terrible when it comes to comparisons and technical explanations (they seriously argue that the Profoto B10 is as powerful as a Godox AD400 which anyone with a brain and access to both devices could convince themselves is a boatload of nonsense) that they would manage to regurgitate some facts about sensor sizes that they read somewhere.

Alas, Lee managed in his typical style in which confidence trumps knowledge to misinform his viewers.


If you keep everything constant (except sensor size, presumably) then you get two wildly different images which cannot be reasonably compared to each other.

At the 6:56 minute mark, Lee attempts to start the one experiment that makes sense:
  • have both cameras at the same position (otherwise perspective would change and with it DOF).

  • compensate for the larger sensor by using a longer focal length (otherwise the FOV would change and with it the light gathered, DOF upon cropping, etc.)

  • keep the shutter speed the same.

His result is that the larger sensor produces an image with a shallower DOF.

This apparently contradicts the title of the video but he offers an explanation: The longer lens is responsible for creating the shallower DOF.

This explanation is wrong. While it is true that using a longer focal length reduces DOF when not changing the sensor size at the same time, the reason for that latter phenomenon is not the longer focal length as such, but keeping the f-stop constant.

You'll only see the reduction in DOF when going from a shorter to a longer focal length, if you keep the f-ratio constant, say, use f/2.8 for both a 50mm and 100mm lens.

You could achieve exactly the same DOF if you stopped down the 100mm to f/5.6. Why f/5.6 exactly? Well, DOF is determined by the aperture diameter (the entrance pupil, to be precise as @Ian Stuart Forsyth pointed out). In the case of a 50mm lens at f/2.8, the aperture diameter is 50mm/2.8 = 17.86mm. Now if you only change the focal length from 50mm to 100mm but keep the f-stop at f/2.8 then you increase the aperture diameter to 100mm/2.8 = 35.71mm. This larger light-passing port is responsible for the shallower DOF, not the the increase in focal length as such. One can prove this by stopping down the 100mm lens to f/5.6, resulting in the same 17.86mm aperture diameter we had for the 50mm f/2.8 lens.

I hope you can agree so far.

Note that f-stoppers use some nice diagrams to show why distance, for instance, affects DOF.
Have you noticed they they don't show you any diagrams to illustrate why increasing focal length changes DOF?
The reason why they don't show you respective diagrams with light rays, etc., is because there is no causal relationship between focal length and DOF.
I suspect that the actual effect -- the increase of the aperture diameter when the f-stop is kept constant -- eludes them and that they don't understand that DOF is essentially the result of a parallax effect, i.e., the larger the aperture, the more angles/positions exist to view the same point in the subject space.

To summarise: Contrary to what f-stoppers purport, DOF is not affected by focal length but by changes to the aperture diameter.

F-stoppers were correct in claiming (mainly through the video title) that a larger sensor does not produce shallower DOF per se.
They were also correct in attributing the change in DOF to the lens.
They were wrong in attributing the change in DOF to focal length.

The reason why the second image shot with the larger sensor showed shallower DOF was not because he used a focal length that was twice as long, but because he used an aperture diameter that was twice as large. Had he used the equivalent f-stop of f/5.6 for the longer lens, he would have achieved exactly the same DOF.



The difference between "myths" and "facts" is that the former can be disproven by experiments while the latter are confirmed by experiments.

I hope you can agree that 100mm is the FF-equivalent focal length compared to 50mm on a 4/3 sensor.
It is not the same focal length (100 <> 50) but it is equivalent because the longer focal length exactly cancels out the wider FOV of the larger sensor.

For all practical intents and purposes, the combination of 50mm on 4/3 and 100mm on FF are indistinguishable. There are some real world practical implications that would allow you to experimentally determine which combination you are dealing with, but theoretically, you cannot distinguish one combination from the other.

I think you know that already. Where it gets slightly trickier is to understand that in order to keep combinations indistinguishable, one also has to change the f-stop. The reason is simple, though. We need to keep the aperture diameter the same, as the latter is responsible for determining the DOF. Hence, the f-stop on the 100mm lens must be twice as large as the one on the 50mm lens.

This tells us that the FF-equivalent f-stop for f/2.8 on 4/3 is f/5.6.

I hope you can see that this is exactly the same conversion we had to do for the focal length.
All photographers seem happy with the idea of equivalent focal lengths, i.e., the notion that you have to adapt the focal length when you change the sensor size.
Far fewer photographers understand the idea of an equivalent f-stop, i.e., the notion that you have to adapt the f-stop when you change the sensor size.



In the comparisons I make or assume, I never ever change the camera to subject distance.

With equivalent shooting parameters, you'll find that you cannot distinguish the FF image from the APS-C image.

You'll find that only one eye is in focus for the FF image, if you choose to use non-equivalent f-stops.
Choosing, say f/2.8, for both shots, make the f-stops look the same numerically, but we know that the equivalent (i.e., the one that achieves the same effect) f-stop for FF is ~f/4.

I hope this helps.
Forum: Travel, Events, and Groups 6 Days Ago  
Kiwi Pentaxians
Posted By Class A
Replies: 16,508
Views: 1,080,636
Thanks for sharing!

I wonder what the seller is on about regarding AF not being ultimately precise due to the screw drive approach. I have no issues with screw drive AF and am not aware of any systematic problem the seller is alleging to.

Makes me wonder whether something is up with that particular copy.
Forum: Travel, Events, and Groups 11-10-2019, 11:47 PM  
Kiwi Pentaxians
Posted By Class A
Replies: 16,508
Views: 1,080,636
Attachment 473209
:)

P.S.: Bit of a difference exaggeration due to only using a hood on the HD D-FA*, but there is a difference regardless of hoods. :)
Forum: Flashes, Lighting, and Studio 11-10-2019, 11:28 PM  
Looking for some help setting up a Cactus laser trigger setup
Posted By Class A
Replies: 19
Views: 477
Too bad that it doesn't work out of the box. It seems you are running a firmware version on the V6 that made it compatible with the V6II but unfortunately meant that the V5/LV5 side could not longer be supported. A downgrade (or sidegrade) to a firmware using the V5/LV5 protocol should do the trick.


It is unfortunate though that this happens in single mode as well. As I said, in this mode, the LV5 artificially prolongs the event duration in order to give most cameras sufficient time to recognise the trigger event, even if the original sensed event is way too short. It's been a long time and I never used the "delay" and "freeze" features extensively, but potentially you can increase the trigger duration of the LV5 sensor by setting a longish freeze period (something over "150ms" should be plenty). Worth a try, but as you say you currently have a setup that works, so you'll only need to tinker some more if you want to use other configurations.


Sorry, I don't. For most applications the delay is negligible. For very fast moving objects, I would expect to see a noticeable difference in distance travelled, though. However, most of the time you can just compensate for that by moving the "laser fence" more towards the origin of travel.


Whether you are using radio communication or optical triggering, I think in both cases you'd get good results.
The flash pulses themselves have a duration (which is much larger than the delay, at least near full power) so you'll get an overlay of two exposures at different times but they'll be very much smeared together because of the relatively long flash pulses.

Firing all flashes at the same time by one source should be more accurate but I wonder how much of a visible difference would be observable.
Forum: Photographic Industry and Professionals 11-10-2019, 11:04 PM  
Rant: camera prices and quality per format
Posted By Class A
Replies: 184
Views: 5,059
This is correct when it comes to the edges of current understanding. If a subject area is not fully understood yet then experts will differ in their takes one what might be the correct answer. Often they are all wrong and it takes someone new to find the correct path. :)

I do not agree that we are dealing with this case here as the underlying principles of imaging are well understood and there are no debates among experts.


I don't know if you are talking about me.

I try to stay constructive during discussions and find myself more often at the receiving end of "you are wrong" (or "stupid" for that matter) allegations than I tell others that they are wrong.

However, I feel comfortable in stating that I am right because I understand the subject area well enough and the predicted effects can be practically demonstrated.

If you are asking for more modesty on my behalf, how would you feel if someone told you shouldn't be so sure that "1+1=2"? How would you respond to someone telling you that there are a variety of opinions and no one should ever say that their result is the correct one?

Again, I'm not sure you suggested I'm being to assertive about my "viewpoint", I just offer the above as a point of discussion if you did.



Of course, blind belief or trust is always wrong.

However, if a theory predicts a certain performance difference and a measurement confirms exactly that difference, it seems unwarranted to suspect that the measurement cannot be trusted. In particular, if the same kind of measurement differences are confirmed by different sources.


Luckily, with the topic at hand, it is possible to show that all the talk about noise, etc. can be demonstrated to be true by taking respective images.
One just has to agree that a fair comparison requires the same image contents to be shown, i.e., if someone suggests to just compare a cropped (say APS-C) image with a larger (say FF) one with both images showing a different FOV then a fundamental discussion becomes necessary. With that understanding established, though, one just takes images and can see for oneself which party makes the correct predictions.


I don't see how that can be a method of finding truth.
Belief, by definition, does not require evidence. Evidence, however, is a vital ingredient for establishing truth.

Using this second maxim, someone would only acknowledge things they happen to believe, meaning that they could many times acknowledge things that have no basis in reality.

I'd rather say
"I'll trust a theory if it is supported by evidence." and
"I'm confident discussing a subject matter if I understand it and have seen evidence that my understanding aligns with reality."
Forum: Flashes, Lighting, and Studio 11-10-2019, 10:41 PM  
Acon R930 P-TTL radio trigger and 1/8000 Sync
Posted By Class A
Replies: 176
Views: 35,159
First of all, I don't see what is so exciting about using a Nikon flash on-camera.

Almost all flashes work on a Pentax camera and only if you want P-TTL then you need a Pentax-dedicated flash or an adapter.
So the application range (one has a Pentax camera, a Nikon flash, wants to use the flash on-camera, and wants to use P-TTL) is rather narrow.

Why not just use a Pentax compatible flash in the first place or use a third-party flash that mounts on a Pentax camera and can be controlled via radio without needing an additional radio receiver? In almost all cases, it is better to get the flash off-camera anyhow.

If on-camera flash usage is indicated then I'd recommend using a flash bracket rather than putting the weight of a flash on a transmitter. Once the flash is on a bracket, you can either radio control it directly or add a receiver (which you typically already have if you have a transmitter).

Regarding other systems supporting the same "adapter" functionality, it is my understanding that the Cactus V6II with the X-TTL firmware does this. It treats the on-transceiver hot-shoe as a fifth group and one can assign a flash system and flash model to the hot-shoe. So the V6II should work as a translator between P-TTL and i-TTL. It performs this translation function when using two transceivers so I don't see why it wouldn't work when using a single unit, given that camera system and on-transceiver flash system can be configured independently from each other.

Anyhow, AFAIC, off-camera flash usage is far more interesting and a number of systems support more than just supporting Nikon flashes at the receiver end, including the nice option of not having to deal with an extra receiver attached to the off-camera flash at all. A receiver-less setup is less bulky, quicker to set up, and spares one the trouble of managing the receiver batteries.
Forum: Travel, Events, and Groups 11-10-2019, 10:27 PM  
Kiwi Pentaxians
Posted By Class A
Replies: 16,508
Views: 1,080,636
One advantage of high-MP cameras is that they give you better cropping potential.

One doesn't need to be as precise when framing as cropping in later still leaves more than enough MP headroom and if one finds a picture within a picture one can often crop into it while still maintaining a very decent amount of resolution.

Of course such cropping also magnifies lens weaknesses, so it doesn't come for free. Also, it seems questionable to have increased storage demands throughout just for supporting the occasional cropping. But still, I think cropping potential has its advantages, with the most obvious one being the K-1 having the ability to double as a 36MP FF camera and a still decent 16MP (cf. K-5, etc) APS-C camera. :)
Forum: Flashes, Lighting, and Studio 11-10-2019, 10:21 PM  
Second Curtain with Godox AD200/Xpro-P/XT2
Posted By Class A
Replies: 11
Views: 430
Seems like an unnecessary limitation caused by the X2-T.

Obviously P-TTL features such as automatic exposure or HSS are not available in the Pentax system when a manual lens is used. However, the use of a manual lens shouldn't stop the trigger from emulating a regular (non-P-TTL) flash and send power level commands to flashes regardless of whether the group is in TTL or M mode.

I'm not 100% certain about the V6II firmware variants right now but I'm pretty sure that at least the V6 provides manual power level control when a manual lens is attached to the camera.
Forum: Flashes, Lighting, and Studio 11-10-2019, 09:55 AM  
Second Curtain with Godox AD200/Xpro-P/XT2
Posted By Class A
Replies: 11
Views: 430
Yes, the (very small) delays they support are meant for fine-tuning HyperSync, not for what you have in mind.


Yep, second-curtain flash triggering is a P-TTL feature and not available outside of P-TTL. Too bad, I say, but it doesn't make a difference. :)


That's exactly what I would have proposed as a solution.

This workaround sucks if you have multiple lights that you all want to fire with the same delay (e.g., when changing the shutter speed) and even when using only one light it is still less convenient than just changing a value on the trigger rather than walking between camera and light all the time, but at least there is some form of workaround.
Forum: Flashes, Lighting, and Studio 11-10-2019, 09:42 AM  
Looking for some help setting up a Cactus laser trigger setup
Posted By Class A
Replies: 19
Views: 477
As @BrianR has pointed out, you don't need that intermediate V6 in a TX role.

The LV5 sensor can trigger another receiver (and hence camera) or flash via radio.
The only snag you may potentially hit is an incompatibility between the LV5 and the RF60 firmware versions. Potentially, you might need to downgrade the RF60 firmware version to an earlier one, so that the RF60 can still talk the older flash protocol used by the LV5 sensor.

BTW, if you can place the LV5 sensor near the camera/flash, you could even fire the camera/flash directly without involving radio communication.


Again, the use of an additional V6 unit in a RX role is not necessary as your Cactus flash has a built-in radio receiver already. Currently you are using two superfluous units that only introduce lag.

If you have reliability issues with firing the flash directly from the LV5 sensor than try angling the flash body slightly differently (while compensating with the flash head). Alternatively, try using a different flash channel, making sure you go beyond five. The first five channels on the older flash protocol used on the LV5 all use the same frequency (to implement a poor man's approach to group broadcasting).


I suspect this is due to the LV5 generating a trigger signal that is too short (unless the failed trigger events are due to the camera going into a sleep mode from which it has to sloooowly wake up before it can respond to a trigger event).
Are you running the LV5 sensor in "Multi" mode?
If so, switch it to "Single" mode and with a bit of luck the extra trigger signal padding that is then used will be sufficient to reliably fire your camera.

BTW, a long time ago I wrote a review about the LV5 that you may find useful. I only tested the version without the useful "delay" and "freeze" controls, but it is unlikely that you'll need these features in your application (except perhaps the "freeze" control if you are suffering from too many subsequent trigger events).


That is one approach and most recommended if the camera lag time is either
  1. too long to allow capturing an event, even when placing the "laser fence" such that it is broken long before the moving object (here the arrow) hits the scene of impact, or

  2. too variable. The camera, depending on what is currently processing internally, does not always have the exact same response time. Flashes are not only significantly faster to respond but also with much less variability.


@bobbotron If you want to keep firing the camera (instead of the flash) then I would recommend to connect a V6 in RX mode to the camera in order to trigger it, and use a V6 mode in TX mode (using a different channel) on top of your camera to trigger your flash. That way, you won't have to manually achieve synchronisation between camera and flash.

However, in your application it seems more promising to reduce the ambient light to a level that allows a longer exposure so that the flash will decide the exact point of exposure, not the camera.
Forum: Flashes, Lighting, and Studio 11-10-2019, 09:21 AM  
Xpro-P TTL Wireless Flash Trigger for Pentax
Posted By Class A
Replies: 264
Views: 25,967
My Flashpoint R2 Pro Mark II has arrived. Haven't had time yet to put it through its paces. :(

Let me know if I should check something. :)
Forum: Travel, Events, and Groups 11-10-2019, 09:14 AM  
Kiwi Pentaxians
Posted By Class A
Replies: 16,508
Views: 1,080,636
Well, it has worse AF performance than the Panasonic S1 series and the latter is already annoying with its "wobble in"/"wobble out" approach to focusing.

I love the rendering of many Leica lenses, and the SL2 has a lovely design and is probably a nice camera to use. However, in terms of AF, given that it relies on CDAF (contrast-detect AF) only, i.e., it neither uses OSPDAF or DFD technology, it gives Pentax a run for its money for the worst AF system in the industry! :lol:

Please note that I don't mind Pentax AF at all. It is plenty fast enough for me and I like that it favours accuracy over speed. So please don't put me on record as stating that Pentax has the worst AF system in the industry, I was only playing on how it is commonly perceived. :)

I would seriously be annoyed by an EVF that threw into my face with digital precision how much the camera is struggling to obtain focus. It has even been reported that the struggle is not just visually annoying but the camera at times even decides to stop focusing before or behind the subject. :(

In short, I think Leica shine with their glass, not with their (digital) cameras.
Forum: Flashes, Lighting, and Studio 11-10-2019, 09:02 AM  
Acon R930 P-TTL radio trigger and 1/8000 Sync
Posted By Class A
Replies: 176
Views: 35,159
So why do you think that the Acon system is unique in that when other systems accomplish the same?


Again, that only applies if you rely on optical communication. For radio communication, at least one receiver is required; as in any other system.

Other systems have speedlights or strobes that have built-in radio receivers, whereas that's not the case for the Acon system.
That, indeed, is a real difference.
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