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Forum: Pentax K-1 4 Hours Ago  
Just tried out the K-1
Posted By Class A
Replies: 24
Views: 1,676
"F-stop is f-stop" is true in the same sense as "Focal length is focal length". Correct, from a certain perspective (physical attributes of a lens don't change, regardless of sensor size), however, incorrect when considering the effect of an attribute, such as f-stop or focal length, on the image, depending on format size.


Correct.


Yes, the image will not "magically darken".

However, remember that your film will be the negative (once developed). Now imagine to produce the same image on photographic paper, once using the full negative (FF) and once using a cropped negative (APS-C). You won't be able to. Larger negatives yield better quality images (less noise). That's the whole point of large format photography.

Note that the "cutting sides off" approach is not helpful in making useful comparisons. If you cut sides off a negative and then develop with an unchanged enlargement factor then you'll get a crop of the original image. This crop will be identical in quality to the crop you'd get by cutting sides off the photographic paper, but you can hardly compare two photographic prints where one has twice the size and shows more of the scene, can you?

If you attempt to get the same/similar information into the smaller negative (by using a wider lens, or "standing back") then you will have to use a bigger enlargement factor in order to get the same photographic print as you can get from the original FF negative. The bigger enlargement factor results in more noise in the photographic print. N.B., only using a wider lens (with the f-stop adjusted by a divisor of 1.5) will give you the same information. "Standing back" will result in a different perspective and different DOF.

The enlargement factor (which is higher when using APS-C compared to FF) is easily forgotten about when talking about digital photography, but as soon as you print the same image to a given output format (say 16x20) then you'll notice that capture format (film size or sensor size) does matter.

This is not a straightforward topic. In order to not derail the thread, I'll only say that "f-stop is f-stop" is not a correct statement in every sense of the phrase, just like "focal length is focal length" is not a correct statement in every sense of the phrase.
Forum: Flashes, Lighting, and Studio 1 Day Ago  
AF 540 FGZ How to tell if they are nearing End of Life
Posted By Class A
Replies: 11
Views: 342
Enloops support quicker recycle times, though, so one has to add a bit to that time to obtain a normal figure for non-rechargeable batteries.

The speed advantage for the Eneloops probably depends on the flash model so I cannot speak to the factor one should expect, but I'd expect some difference. Eight seconds seem too long, though.
Forum: Pentax K-1 1 Day Ago  
Too much noise on K-1
Posted By Class A
Replies: 49
Views: 5,405
You are probably not making a fair comparison; you cannot zoom in to 100% on both images and look at the pixel noise. The K-1 would give you more magnification and hence more noise.

See the post by howieb101.
Forum: Flashes, Lighting, and Studio 2 Days Ago  
Cactus V6II - Multi brand HSS?
Posted By Class A
Replies: 31
Views: 769
Yes, you need one V6II unit on the camera and another V6II unit attached to the Metz 58 AF-2.

EDIT: Sorry for the duplication. Pschlute's answer was on the next page and I only saw it after I posted mine.

It is nice to not worry about another device and its associated set of batteries when using an RF60(x). It also recycles rather quickly, doesn't require a pre-flash when used in manual control and has some further advantages.

However, if one already owns a Metz 58 AF-2 then it is less costly to upgrade it with a V6II unit, compared to buying a new RF60(x).
Forum: Pentax K-1 3 Days Ago  
Just tried out the K-1
Posted By Class A
Replies: 24
Views: 1,676
First of all, I understand "ISO invariant" or "ISO less" as a property of a sensor, not a description of a particular implementation.

AFAIC, it does not matter whether there is amplification in the analogue domain or not, the defining principle of an "ISO less" sensor is that it doesn't matter at which ISO setting one captures the image, as amplification in the digital domain after the fact is just as good.

I don't know any sensor that actually achieves any significant advantage by amplifying in the analogue domain before A/D conversion compared to a sensor with extremely low read noise, but I'm happy to learn.

As I understand, analogue amplification was used when read noise levels still suggested that analogue amplification should be used before A/D conversion in order to maintain an improved SNR.

Since the advent of extremely low read noise sensors, there is no need anymore to artificially boost the signal before conversion with all the problems analogue amplification entails.


The actual signal also gets "smaller and smaller" when analogue amplification ("signal conditioning" as you call it) is used. Amplifying a signal does not increase the information content in a signal. On the contrary, the amplification process itself will deteriorate the signal by introducing noise, potential non-linearities, etc. All these problems were a good trade-off when sensors still had very high read noise levels (and thus struggled with very low signals), but with modern sensors that is no longer the case.


Do you maintain that is also true for modern medium format sensors, such as the one used in the Fuji GFX 50S?

My understanding is that the low read noise of modern CMOS sensors implies that it is better to amplify in the digital domain rather than in the analogue domain. In other words, "ISO less" sensors are not a result of cost-saving as you present it, but a result of advances in A/D technology that ultimately not only give photographers cleaner images to start with but also the ability to avoid overexposure without having to pay a (increased noise) price.
Forum: Pentax K-1 3 Days Ago  
Just tried out the K-1
Posted By Class A
Replies: 24
Views: 1,676
It most certainly is not a disadvantage. There are no downsides to ISO invariance whatsoever.

It is generally considered to be an advantage as shooting with an ISO setting that is nominally too low, allows one to guard against blown out highlights without having to pay the price of increased noise due to underexposure.

A sensor that is not ISO invariant requires one to always shoot at the edge of ISO settings, in order to avoid any avoidable noise. This carries the risk of blowing out highlights. An ISO invariant sensor is more flexible in that regard.
Forum: Pentax K-1 3 Days Ago  
Just tried out the K-1
Posted By Class A
Replies: 24
Views: 1,676
It is just a blessing, as you can simply stop down, if you prefer a deeper DOF.

You don't lose out by stopping down. Shooting a 50mm lens at f/8 on FF provides the same amount of light as a 33mm lens at f/5.8 on APS-C.
In short, don't worry about losing light. You don't. The only real difference between FF and APS-C is that there are some FF lenses (e.g., a 50mm f/1.4) which have no equivalent on APS-C. Apart from those "holes" in the APS-C lens line up, you can always emulate one camera with another by just choosing the appropriate lens and settings. Ergo, FF gives you more opportunities (with the right lenses), but you don't have to pay a price (only in the sense that you have to "pay" for more light than you'd be able to get on APS-C with a shallower DOF).


Yes, but it also provides more options than an f/2.8 zoom on APS-C.
The equivalent zoom on FF is an f/4 zoom, so for instance the 60-250/4 lens would be a good FF lens for you, if you don't want to have more options than you have with an f/2.8 zoom on APS-C.
Forum: Flashes, Lighting, and Studio 3 Days Ago  
Neewer flash trigger problem
Posted By Class A
Replies: 3
Views: 245
A trigger should work up until and including 1/180s (a speed that is only available when 1/2 EV steps are chosen or the "X" mode is chosen).

The camera will never detect a simple trigger like the one you have, but triggering should still work.

A potential cause for misfiring could be that the transmitter is too close to the receiver. Try to keep some 30cm+ between the transmitter and the receiver, just to make sure.
Forum: Flashes, Lighting, and Studio 3 Days Ago  
Cactus V6II questions
Posted By Class A
Replies: 38
Views: 821
Yes, good point.

I typically discard that option as it forgoes remote power level control and thus relegates a relatively pricey V6II to something a very cheap trigger could do. However, you are right, in case a pre-flash would be very undesirable operating the flashes in manual mode is of course an option.
Forum: Pentax News and Rumors 3 Days Ago  
Pentax K-1 Mark II DSLR camera detailed specifications leaked
Posted By Class A
Replies: 389
Views: 30,190
Again, that's not what I said.

I won't respond to you anymore, as you keep putting words into my mouth.


Take it from the horse's mouth: My points about undesirable RAW manipulation was not "designed to create negative emotions". You are entitled to your ideas regarding my motivations and intentions, but they are 100% false.


That's besides the point. I never said that the processing does not result in more pleasing or cleaning looking images.

I only said that it is smarter to leave any processing of the data to a later, out-of-camera, stage.

It seems a discussion here is no longer fruitful. If I don't respond anymore, this shouldn't be construed as tacit approval on my behalf.
Forum: Pentax News and Rumors 3 Days Ago  
Pentax K-1 Mark II DSLR camera detailed specifications leaked
Posted By Class A
Replies: 389
Views: 30,190
If you refer to their "ISO 50" setting, that is not a meaningful low ISO setting. It just creates an overexposed image. This will work fine, as long as the original scene could have been captured with ISO 100 as well. Otherwise, you'll get blown highlights. In other words, this "ISO 50" setting, does not result in more dynamic range compared to "ISO 100".


No, they don't. The K-1's DR is higher than that of the D800 and slightly lower than that of the D810.


I don't have a reliable source for which sensor exactly is used in the D810. In the D800, it is the IMX094AQP but a further complication would be to find out what the exact prices were at the time Pentax had to make a decision. It seems logical to me that Sony would charge more for a more capable product. If you can provide evidence that a sensor with more dynamic range does not command a higher price then I'll be happy to accept that I jumped to a conclusion. BTW, Nikon appears to work closely with Sony and sometimes do their own designs and/or dedicated D/A converters. This complicates this particular story quite a bit.

None of this matters for what I've been trying to say, i.e., that nominal IQ is created by the sensor, not by an image processor.
Forum: Flashes, Lighting, and Studio 4 Days Ago  
Cactus V6II questions
Posted By Class A
Replies: 38
Views: 821
No radio trigger supports analogue TTL in the sense of controlling exposure by means of light reaching "the TTL sensor".

Note that only a couple of early *ist Pentax cameras supported this analogue TTL approach in the digital age. Your 645N film camera supports that approach, but no radio trigger does.


Unfortuntely, the AF-500FTZ doesn't support P-TTL so that won't work either.


That's not correct.

The V6 system requires flashes to be set to "TTL" (not "P-TTL") mode. The V6 could remote control the power level of a AF-500FTZ in principle, but sadly the latter is not compatible with the V6. As kaseki stated, the AF-500FTZ appears to support a pure digital TTL protocol (which is not the same as "P-TTL"), whereas the V6 requires the presence of the analogue TTL protocol.


The V6 definitely cannot remotely control the power level of the AF-500FTZ.

BTW, even if the V6II worked with the AF-500FTZ, you probably wouldn't have wanted it anyhow. A V6II receiver will always cause a pre-flash. When a V6II trigger is used in combination with RF60x units then there won't be a pre-flash unless one is needed (for automatic metering). However, a V6II trigger controlling V6II receivers will always imply a pre-flash, even in the case of pure manual control.
Forum: Pentax News and Rumors 4 Days Ago  
Pentax K-1 Mark II DSLR camera detailed specifications leaked
Posted By Class A
Replies: 389
Views: 30,190
Why are you putting words like "K-1 Mark II is no good" into my mouth?

I never said anything like it.
I only argued the case that post-processing should occur outside the camera, as faster hardware and new algorithms can provide continuous improvement over time. However, this only works optimally, if you have access to the raw data from the sensor. Any additional processing in the camera will "bake in" some correlation into the data that you cannot remove anymore after the fact. DxOMark has produced evidence for such RAW data tampering with some older Pentax cameras (for high ISO settings only). Luckily, this practice has never created any significant downsides as one can simply shoot at a lower ISO setting (ISO 1600 has been the threshold) and then push in post-production. Due to the "ISO less" nature of modern Sony sensors, there is no difference between pushing in post or using high ISO settings during shooting. The only downside of pushing in post is that visual feedback during shooting won't be available, as the back LCD will show a heavily underexposed image.

I never intended to create "some negative emotions regarding a new Pentax product". I love my Pentax gear and always wish Pentax the best. This doesn't make me close my eyes, though, and hail the addition of what appears to be a fast post-processing stage as an actual achievement for RAW shooters.

If anyone can explain how the "accelerator" unit is actually increasing the fidelity of the sensor data, rather than performing post-processing that should be left to a RAW converter, then I'd be most grateful. The architecture of modern Sony sensor appears to make it impossible to allow camera manufacturers to tweak their performance which appears to leave RAW data manipulation as the only form of achieving a better looking output.


Sure, but see above for the optimal place to create a "look".


Providing meaningful low ISO values requires to increase the full-well capacity of sensor sensels. In other words, this requires different hardware as opposed to different software. A meaningful low ISO value -- as opposed to software-emulated ones, one where one simply underexposes, or those achieved by photon attenuation which increases noise -- directly translates into a higher dynamic range.

Note that the K-1 "only" offers ISO 100, unlike the D810, which offers ISO 64 (for simplicity, I'm using the manufacture figures here, not the measured values). It is therefore highly unlikely that the K-1 uses the same sensor as the D810, a "fact" that has often been purported. It is much more likely that the K-1 uses the same sensor (or a variant of it) as the D800. As Pentax has demonstrated with the K-5, they know how to exploit the option of lower ISO values (ISO 80, in this case) to their advantage. The "ISO 80" setting moved the K-5 considerably up the DxOMarK score ladder and obviously has real advantages to photographers as well.

To be clear, for me personally, the K-1 offers plenty enough dynamic range. I personally don't need a lower ISO setting and in my view the K-1 is an absolutely fantastic camera as it is. However, there are reasons why the D810 offers a lower ISO setting:
  1. meaningful low ISO settings translate into higher dynamic range.

  2. higher dynamic range is not only useful for photographers but also for achieving top positions in the DxoMark ranking (which has marketing implications).

  3. sensors with higher dynamic range are more expensive. Pentax did not use a Sony sensor similar to the D810's because either the sensor was too expensive (relative to the benefit) or potentially because it had some other characteristics they wanted to avoid. I wouldn't know, however, what those negative characteristics could have been.

Forum: Pentax News and Rumors 4 Days Ago  
Pentax K-1 Mark II DSLR camera detailed specifications leaked
Posted By Class A
Replies: 389
Views: 30,190
The KP's files can be great because
  1. the sensor is great, and/or

  2. the RAW files are baked (at high-ISO settings).

Just because you "hate" baked RAW files, doesn't meant it doesn't happen for the KP.

I cannot comment on whether or not KP RAW files are massaged by Pentax. I do know, however, that a modern Sony chip delivers digital numbers with no leeway for the camera manufacturer to improve performance by adding additional chips or some analogue circuits.

The only approach to making RAW files look better out of camera, is to manipulate the RAW data. So, again, for actually better performance (as opposed to "better looking"), another sensor is required.
Forum: Flashes, Lighting, and Studio 4 Days Ago  
Newbie question - cross manufacturer trigger compatibility
Posted By Class A
Replies: 10
Views: 485
That must have been Cactus V2 (their first trigger, I believe). These were pretty terrible just like many other early triggers in that price range at the time. Some DIY antenna mods made the V2 triggers usable apparently.

My first Cactus triggers were the V4. They had a rather limited range (~15m in my experience) but were rock solid in that range. The V5 had a 100m+ range and, again, were rock solid. The V6(II) use the same radio technology as the V5, so again, the performance is flawless.

These triggers are not only "better" than the shoddy V2, they leave nothing to be desired in terms of reliability.
Forum: Flashes, Lighting, and Studio 4 Days Ago  
Cactus V6II - Multi brand HSS?
Posted By Class A
Replies: 31
Views: 769
The current Sony hot-shoe is still a proprietary ("Multi Interface Shoe") one. Yes, they went back to the standard ISO centre contact placement, but Sony uses a number of additional pins at the front of the hot-shoe. This is the reason why there is a Cactus V6IIs ("s" for "Sony"). Only this version can fully work with Sony cameras and flashes, i.e., support HSS (or more with the X-TTL firmware variant).
Forum: Pentax News and Rumors 4 Days Ago  
Pentax K-1 Mark II DSLR camera detailed specifications leaked
Posted By Class A
Replies: 389
Views: 30,190
Have a look at this description of the Sony column-parallel conversion technology.

The "per pixel noise reduction" some attribute to the new accelerator unit is already done on the sensor. Technically, it is " reset level substraction". As I said before, without changing the sensor, Pentax cannot increase the nominal performance (only make images look prettier; a job that should be left to post-processing out-of-camera).
Forum: Pentax News and Rumors 4 Days Ago  
Pentax K-1 Mark II DSLR camera detailed specifications leaked
Posted By Class A
Replies: 389
Views: 30,190
This is probably the "accelerator" chip.

There is nothing that such a chip can do to change the nominal noise performance of the sensor. Such a chip can speed up noise processing and thus enable the use of noise reduction algorithms that would otherwise take too long to execute, however it cannot increase information in the RAW data.

Such a chip may still be useful for those shooting JPGs or appreciating baked RAW files, but unless Pentax will be using a different sensor, the actual noise performance won't be better than that of the K-1.
Forum: Pentax News and Rumors 4 Days Ago  
Pentax K-1 Mark II DSLR camera detailed specifications leaked
Posted By Class A
Replies: 389
Views: 30,190
All RAW converters apply some tone curve.

C1 supports choosing a "linear" tone curve and when you choose it, it becomes obvious why this is not the default.

RAW data is a linear encoding of the sensor data. I verified this myself with measurements, using dcraw to look at the RAW data without any tone curve applied.

N.B., some software (e.g., Photo Mechanic or Faststone) shows you the JPGs that are embedded in RAW files. Consequently, such software will show any adjustments you may have made in camera. Faststone has an option to take the RAW data instead, but the default is to use the embedded JPGs (for snappier performance).
Forum: Flashes, Lighting, and Studio 6 Days Ago  
Newbie question - cross manufacturer trigger compatibility
Posted By Class A
Replies: 10
Views: 485
Pocket Wizard triggers provide no advantage over Cactus triggers, on the contrary.

Cactus triggers allow remote power control, HSS, and with selected flashes even full P-TTL support. Pocket Wizard triggers do none of that and the Cactus triggers are more than fast enough to support the sync speed of Pentax DSLRs.

@_pauls: Pocket Wizard triggers were once the gold standard of the industry. However, they never offered something specific to Pentax and due to their high-end pricing and the rise of good to excellent quality third-party trigger alternatives, went into financial trouble in 2014.

You'll be fine with non-specific Pentax triggers but only if you do not need HSS (high-speed sync). If you want the latter, Cactus triggers are indeed your best choice. Acon also did some P-TTL triggers for Pentax (Acon R930) but their website no longer exists, so it seems that option has disappeared.
Forum: Flashes, Lighting, and Studio 6 Days Ago  
Gala/dance Event Photography, K-3, Would like to use Metz 52 to trigger to 2-3 slaves
Posted By Class A
Replies: 4
Views: 270
Yes, but "wireless" here means "optically", so the disadvantages mentioned by mcgregni apply.

Depending on the scenario, optical triggering can work well, but if you are expecting to move a lot in relation to the slave flashes, radio triggers will be a much better idea.
Forum: Flashes, Lighting, and Studio 6 Days Ago  
Cactus V6II - Multi brand HSS?
Posted By Class A
Replies: 31
Views: 769
Sure, I'm using a Metz 58 AF-2 and the V6II works fine with it (both multi-brand and X-TTL firmware variants).

As for the Yongnuo 600EX-RT II, it is definitely not supported by the X-TTL firmware variant (as the flash does not implement P-TTL). I don't know whether it is compatible with the multi-brand firmware variant for the V6II. I'd say the answer is probably "yes" and one of the existing Canon profiles should do the job. However, there could be complications due to one or both of the manufacturers not quite implementing the Canon protocol 100%.


That's not true. :)

TTL is supported by the X-TTL firmware variant for a wider range of flash models. The requirement is that the flash model supports P-TTL. Again, even models not already supported with an existing flash profile may work with the V6II, depending on how faithful their P-TTL implementation is.
Forum: Pentax News and Rumors 6 Days Ago  
Pentax K-1 Mark II DSLR camera detailed specifications leaked
Posted By Class A
Replies: 389
Views: 30,190
What is your insider knowledge on this?

What hardware was upgraded?

I understand that the same Sony sensor is used, which means that nominal noise performance will be identical. Modern Sony sensors include the A/D stage and there is nothing (not even ultra-stable analogue voltage supply) a camera manufacturer can do to influence the nominal sensor noise.

It is, of course, possible and customary to bake RAW data in order to eliminate noise, trying to do it in a manner to be not called out by DxOmark (who measure unnatural correlation in order to uncover noise reduction on RAW data which ultimately decreases image detail as well).

In my view, RAW data should not be manipulated and I don't see the point in providing any new/changed processing of RAW data. Let's not even consider talking about JPEGs for a camera of the calibre of the K-1. High ISO numbers like 819,200 don't mean anything, really as IQ at that level will be abysmal. If quoting such numbers helps selling cameras, that's fine by me, but any serious photographer will not be impressed by a change from 204,800 to 819,200, given that the sensor is (apparently) unchanged.

I have no idea what the new "Pixel Shift Resolution (SR II)" is about, but apparently it does not provide super resolution, as there are no additional options mentioned in the specs. Was there anything wrong about the Pixel Shift technology in the K-1?

Anyhow, I'm happy if a new model gets Ricoh some exposure again, but it would have been nice if some modest changes (say improved USB/card speed) had created more incentive for existing K-1 users to upgrade.

N.B., I keep hearing the argument that the K-5 II upgrades were minor/cosmetic as well. That's absolutely not true. The K-5 had a flawed AF system that was sensitive to colour shifts. The K-5 II fixed that with an entirely new AF design. The K-5 defect did not manifest itself in every AF situation, but nevertheless fixing its inherent disadvantage required a major development and the K-5 II (+ K-5 IIs) were all but practically unchanged versions of their predecessor.
Forum: Pentax News and Rumors 02-09-2018, 10:07 PM  
K-1 Mark II!
Posted By Class A
Replies: 875
Views: 87,789
The Cactus V6II makes HSS work in conjunction with a 645Z.

There may have been firmware versions with issues, but in principle, HSS is possible with the 645Z.

Not to mention the Priolite and Cononmark alternatives, that both support HSS on the 645Z.
Forum: Pentax News and Rumors 02-09-2018, 09:52 PM  
Next hours or days we get a new firmware for K-1
Posted By Class A
Replies: 190
Views: 20,905
Yes, I've been secretly hoping for that to happen for the K-1 Mark II / K-1 situation as well. The phrasing "cancelled" made it appear very unlikely, but as I said, this could be a language issue.

By releasing a K-1 Mark II first and then updating the K-1, Pentax can have their cake and eat it too. They'd be able to get all the attention for a new release and then can later appease K-1 users by releasing a firmware that gets the K-1 to the K-1 Mark II as closely as possible.

I'm pretty sure that one significant reason as to why Pentax still exists as a brand is the brand loyalty of their customer core. I'd say it would be dangerous to mess with it.
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