A Banding Affect in Av (automatic exposure) Modes?

Hai everyone :)

My name's Bruce and I'm a Pentaxian. I own the Full-Frame K-1, and before grabbing a V6ii trigger and RF60X Flash I was using the AF540FGZII flagship flash from Pentax.

Now I actually shot a lot with this flash, and horridly (and shamefully to admit) in Av mode! Sometimes outside (so HSS worked etc), and more often than not the exposure was fine despite a great deal left to 'automation'.

I recently required the aforementioned cactus products, and whilst everything seems to work ok in Manual Mode, I have found that Av mode brings about a 'banding affect' to all my shots. Usually the upper part of the shot is brighter than the lower part of the shot.

In the two images provided, one shot is in Manual Mode (no banding effect), the other in Av mode (with the banding/bright upper part of the frame). Here's where it gets a little interesting. The Exif for the Manual Mode shot was ISO 800, shutter speed 1/80, f2, and when I toggled to Av mode I actually took the camera off Auto-Iso and set the ISO to 800 also, this then also gave the exact same shutter speed and f number, yet the banding was still there. I thought perhaps Auto-Iso was contributing, but it seems that even when I take less automation away from the Av mode (such as taking Auto-Iso off) the issue is still persistent.

Can anyone explain what is going on here? Is this common place, and the recommendation is just to shoot manual mode (which I probably should anyway).

Cheers,

Bruce

Comments

  • Interesting phenomenon.

    It is important to realise that the K-1's shutter travel direction is reversed compared to the vast majority of DSLRs, i.e., the frame is exposed from top to bottom, not the other way round.

    The phenomenon you are encountering is probably a difference in flash timing when using "Av" mode compared to "M" mode. It appears a faster flash release in "Av" makes the camera catch an initial peak output of the flash which is missed by the timing in the "M" mode.

    You could try to set a small delay value (~2ms?) on the V6II or RF60X to see whether that shifts the bright part out of the frame.

    I don't think experimenting with the "CUSTOM SETTING" (in the camera setup of the V6II) would change anything as that should only affect shutter speeds in the HSS range, but you could give that a whirl as well.
  • Hai Class A! You live here too! Nice that Cactus have you on loan here as well :D

    Thanks, I will try that and report back.

    I'm not overly scared of switching to Manual Mode, it's just I primarily do my portrait work in Av mode, I'm concerned I may stuff up accidentally shooting in Av mode or something...

    Would the small delay value be global tho, like if I try it and it works for Av mode, would that now then stuff up things in Manual Mode? ie I have to put it back.

    PS I have no idea as of yet how to change the delay settings but I'll poke about :D
  • edited July 2018

    Hai Class A! You live here too!

    Sure, we Pentaxians have to help each other everywhere. :)



    Would the small delay value be global tho, like if I try it and it works for Av mode, would that now then stuff up things in Manual Mode?

    Yes, the delay would be effective independently of the camera mode and will most likely cause problems in "M" mode.

    I'd encourage you to fully liberate yourself from "Av" mode. It's just easier. I never wanted to shoot in "M" when wasn't using flash yet. I didn't see the point of doing some of the work the camera could do. But then I migrated from "Av" to "TAv" which gave me control over two camera parameters instead of just one.

    I still use "TAv" for natural light photography because I don't need to control the ISO setting, other than indirectly through my aperture and shutter speed choices. However, when I'm using flash, I want everything under my control. Allow the camera to adjust just one parameter and you either have a brilliant understanding of its strategy or you become a passenger. :)



    PS I have no idea as of yet how to change the delay settings but I'll poke about :D

    It's in the "FUNCTIONS" menu. Very easy to find and change.
    I recommend downloading the manual as a PDF file as it is searchable and you'll be able to answer such questions yourself in seconds. :)
  • Had a small play again today, I tried 'X' Mode today on the K-1 mode dial, Shutter speed fixed to 1/200 and there didn't seem to be any banding going on here. So it looks to me like Manual and X Mode is fine, just TAv and Av give banding effect.

    I'm actually curious if this is just a 'me' thing and that perhaps something is wrong with my units, or whether this is something all Pentaxians with either a KP or K-1 with V6ii and RF60x are experiencing. Can anyone replicate the issue I'm having?
  • Hi @BruceBanner

    Out of curiosity, what happens if you mount the Pentax flash directly on camera hot shoe without the V6 II and repeat the two shots, one manual and one Av mode?
    Antonio Lao
    Brand Manager
    _____________

    To help us better help you, always state the exact firmware version installed on your Cactus device(s), such as: "1.1.013", "NIK.A.001", "v.103", or "A06".

    TTL or HSS not working on Cactus V6 II and V6 IIs? Be sure to check hot shoe connectivity by doing the <CAMERA INFO> check.

    Feel free to suggest an improvement or share product ideas. Contact us directly at info@cactus-image.com.  At Cactus, we listen. 
  • Antonio said:

    Hi @BruceBanner

    Out of curiosity, what happens if you mount the Pentax flash directly on camera hot shoe without the V6 II and repeat the two shots, one manual and one Av mode?

    Hi Antonio,

    I no longer have the Pentax 540II (sold it), but I do have the Metzblitz 44-AF-2, and can confirm it works normally in Av and Manual shooting (ie like the Pentax there was never any banding in any of the shots I took with it (in HSS or non HSS scenarios). This situation I am getting seems to be purely related to the V6ii + RF60x.
    I was shooting almost always Av mode when using the Pentax 540II or Metz 44.

    Are my units faulty do we think? They are recent purchases from B&H, most definitely still under warranty (even still have their protective stickers on screen etc!).
  • One important point that you haven't mentioned and that is - what firmware version are you using on your V6 II and RF60X?

    We do not have a K-1 nor K-P here with us so we need to borrow again from Pentax Hong Kong distributor to run tests before we can have a conclusion.

    I will report back as soon as we are able to borrow one. Usually this will take a few days to arrange.

    Thank you!
    Antonio Lao
    Brand Manager
    _____________

    To help us better help you, always state the exact firmware version installed on your Cactus device(s), such as: "1.1.013", "NIK.A.001", "v.103", or "A06".

    TTL or HSS not working on Cactus V6 II and V6 IIs? Be sure to check hot shoe connectivity by doing the <CAMERA INFO> check.

    Feel free to suggest an improvement or share product ideas. Contact us directly at info@cactus-image.com.  At Cactus, we listen. 
  • Antonio said:

    One important point that you haven't mentioned and that is - what firmware version are you using on your V6 II and RF60X?

    We do not have a K-1 nor K-P here with us so we need to borrow again from Pentax Hong Kong distributor to run tests before we can have a conclusion.

    I will report back as soon as we are able to borrow one. Usually this will take a few days to arrange.

    Thank you!

    Hi again,

    I will get the exact firmware for you (once I figure out how to get the devices to show it, some kind of holding of buttons and toggling unit on or something isn't it?), but essentially the first thing I did was to download the cactus firmware updater and use that program to successfully update the RF60x and v6ii to the very latest you have to offer (but I will doubly check this later).

    Just quickly though, I thought I'd share a finding with you.

    Yesterday I was sitting in my chair changing some settings on one of my custom mode dials, fine tuning some settings for how I wanted that configuration to work. I was in Av mode, and I was indoors, and I had my Samyang 85/1.4 attached, I noticed that the minimum shutter speed it was allowing was 1/200. I thought... hmm... that's a bit high, let me check the 'Auto-Iso Settings' (this is an option in the K-1 to set where the minimum Shutter speed encountered in Av Mode would be, Slow, Normal or Fast). I was set to Slow, which should have dropped to 1/50, not 1/200...
    So now I was thinking "what's going on", so I went to a better lit environment to continue my tinkering of my settings, I ventured out onto my verandah and noticed that if I took my camera towards to bright light it toggled straight up to 1/8000! If I panned my camera back towards the poorer lighting inside it would drop to 1/200. So in Av mode I wasn't getting anything else other than those two shutter speeds! This was not right I thought, what's going on!?! I then noticed my Cactus V6ii was switched ON (in Tx mode, TTL)!! Once I turned the V6ii unit off I was back to normal Av shutter speed reactions, namely it wouldn't drop below 1/50th (Slow Auto-ISO limit), and it would rotate through all the various shutter speeds available up to 1/8000 depending upon of course the aperture set and available light given.

    So surely this is a major clue to the oddity that is occurring, it seems that even if the flash unit is not on (which it wasn't) but the V6ii is, if the camera is in Av mode it's just not getting to behave normally as it should! It gets only two shutter speeds available, 1/200 or 1/8000!

  • Thanks Bruce for sharing your findings with Auto ISO settings.

    So if you use manual ISO settings, then no more problem with the shadow banding?

    FYI we were able to borrow a K-1 but it's a Mark II. Hopefully there aren't any big differences with yours. I will report back upon hearing back from R&D.

    Thank you!
    Antonio Lao
    Brand Manager
    _____________

    To help us better help you, always state the exact firmware version installed on your Cactus device(s), such as: "1.1.013", "NIK.A.001", "v.103", or "A06".

    TTL or HSS not working on Cactus V6 II and V6 IIs? Be sure to check hot shoe connectivity by doing the <CAMERA INFO> check.

    Feel free to suggest an improvement or share product ideas. Contact us directly at info@cactus-image.com.  At Cactus, we listen. 
  • edited July 2018


    I will get the exact firmware for you (once I figure out how to get the devices to show it, some kind of holding of buttons and toggling unit on or something isn't it?),

    To check the firmware version of the V6II, keep group buttons "A" & "D" pressed while turning the unit on. Make sure you don't accidentally press any other buttons.


    To check the firmware version of an RF60(x), keep the "Next" button pressed while turning the unit on.




    It gets only two shutter speeds available, 1/200 or 1/8000!


    Have you checked whether the camera shows the same behaviour with a P-TTL flash mounted on its hot-shoe?

    This could be just strange P-TTL behaviour. Mcgregni at pentaxforums.com may be able to help with this.

  • Antonio said:

    Thanks Bruce for sharing your findings with Auto ISO settings.

    So if you use manual ISO settings, then no more problem with the shadow banding?

    FYI we were able to borrow a K-1 but it's a Mark II. Hopefully there aren't any big differences with yours. I will report back upon hearing back from R&D.

    Thank you!

    No, there still oddly is. In Av mode on the Pentax, typically it's set up to have only the Aperture under the control of the user, Iso and Shutter speed are automatic, however with a quick scroll of the a dial it can take you out of having Auto ISO and allow the user to override it, thereby having only the shutter speed left to being automatic, however the banding still occurs.
    I haven't tested extensively but I think it is only Manual mode that this issue does not occur, TAv, program and even 'X' still seem to produce it.
    Class A said:


    I will get the exact firmware for you (once I figure out how to get the devices to show it, some kind of holding of buttons and toggling unit on or something isn't it?),

    To check the firmware version of the V6II, keep group buttons "A" & "D" pressed while turning the unit on. Make sure you don't accidentally press any other buttons.


    To check the firmware version of an RF60(x), keep the "Next" button pressed while turning the unit on.




    It gets only two shutter speeds available, 1/200 or 1/8000!


    Have you checked whether the camera shows the same behaviour with a P-TTL flash mounted on its hot-shoe?

    This could be just strange P-TTL behaviour. Mcgregni at pentaxforums.com may be able to help with this.

    V6ii Pen.A.001

    RF60x A07

    I've had Av mode working fine (including HSS) with other P-TTL flashes I've used including my current one I still have lying around, the Metzblitz 44-AF-2 and the pentax af540fgz ii.

    This banding issue is also occuring with the KP I own, so I really doubt either my K-1 and KP are at fault, it is more likely either this is a bug with cactus units, or mine are defective somehow.
    I'm meeting with a fellow Pentaxian this afternoon, hopefully we can swap triggers and flashes and try and establish if we can find any consistencies to the problem.
  • edited August 2018
    Update:

    I met with the fellow Pentaxian who had a V6ii and K-1, however his V6ii was not configured for the test to be conclusive, not firmware wise nor in terms of flashes/brands model etc, so we couldn't really test.

    What I have recently discovered is this tho, which may be contributing to the issue.

    If I put my Samyang 85/1.5 lens on my K-1 (or KP, results are the same), when in Av mode it works as you'd expect, but as soon as you toggle the V6ii on (and be in TTL), then the shutter speed will only exist at either 1/200 or 1/8000, nowhere inbetween (like you'd normally expect).

    If I put a modern Pentax AF lens onto the K-1 (such as the HD DA 35/2.8 Macro), then under the same V6ii settings I do indeed actually get the full shutter speed range as you'd normally expect and not be restricted to only 1/200 or 1/8000 (depending upon available light).

    I shall test some more today.

    EDIT:

    Tested today, and indeed even though the modern AF Pentax lenses behave better in Av mode (ie the shutter speed varies properly throughout), the issue can still persist, occasionally however, it is intermittent as to how bad the banding is.

    Perhaps we just need to go back to the beginning and check my overall settings.

    For example, I own a Pentax, I can tell the V6ii that I using a Pentax camera (Camera&Flash Settings), however what do I put for the flash when using a Cactus RF60x? There is no 'Cactus' in the list of flashes to use... you can choose Pentax, Canon, Nikon for flashes etc, or select 'Other' or 'Manual'.

    What do you advise someone using a Pentax + v6ii + RF760x to use as their settings?
  • Thanks @BruceBanner for your updates.

    Sounds like a camera setting issue to me? I don't get what are the shutter speeds choices being cut down suddenty due to the type of lens attached?

    In the meantime I will ask our R&D try and replicate any of your findings. But too bad we do not have a Samyang lens. Pentax Hong Kong distributor provided us with Pentax D FA 28-105mm. But the camera is K-1 Mark II. Maybe Pentax made some secret changes to camera firmware? I am not sure...

    If you look closely, there actually isn't a flash setting available on the TX unit. You only set the camera system. The flash system and flash profile you see ONLY APPLIES to an on-camera flash, if present.

    Cheers!
    Antonio Lao
    Brand Manager
    _____________

    To help us better help you, always state the exact firmware version installed on your Cactus device(s), such as: "1.1.013", "NIK.A.001", "v.103", or "A06".

    TTL or HSS not working on Cactus V6 II and V6 IIs? Be sure to check hot shoe connectivity by doing the <CAMERA INFO> check.

    Feel free to suggest an improvement or share product ideas. Contact us directly at info@cactus-image.com.  At Cactus, we listen. 
  • Antonio said:

    Thanks @BruceBanner for your updates.

    Sounds like a camera setting issue to me? I don't get what are the shutter speeds choices being cut down suddenty due to the type of lens attached?

    In the meantime I will ask our R&D try and replicate any of your findings. But too bad we do not have a Samyang lens. Pentax Hong Kong distributor provided us with Pentax D FA 28-105mm. But the camera is K-1 Mark II. Maybe Pentax made some secret changes to camera firmware? I am not sure...

    If you look closely, there actually isn't a flash setting available on the TX unit. You only set the camera system. The flash system and flash profile you see ONLY APPLIES to an on-camera flash, if present.

    Cheers!

    Ah ok, that makes sense.

    I have some other older pentax lenses, MF only, some A-Setting ones some without, I'll test later today to see what they are doing in Av mode with the V6ii on, see if they too suffer this oddity of toggling only between 1/200 or 1/8000 in Av mode. Will report back.
  • OK! Thanks @BruceBanner !

    Look forward to your report. In the meantime please send our regards to Natasha. :smile:
    Antonio Lao
    Brand Manager
    _____________

    To help us better help you, always state the exact firmware version installed on your Cactus device(s), such as: "1.1.013", "NIK.A.001", "v.103", or "A06".

    TTL or HSS not working on Cactus V6 II and V6 IIs? Be sure to check hot shoe connectivity by doing the <CAMERA INFO> check.

    Feel free to suggest an improvement or share product ideas. Contact us directly at info@cactus-image.com.  At Cactus, we listen. 
  • edited August 2018
    Hi @Antonio,
    I've tried the scenario Bruce described with my K-1 (V1.40) and Samyang 85/1.4 in "A mode" and see the same behaviour (running V1.1.013 on my V6II).

    However, I also see the same behaviour when I mount my Metz 58 AF-2 in "P-TTL HSS" mode on the K-1.
    This very much appears to be some strange K-1 behaviour, as
    1. it also occurs with a P-TTL flash, and
    2. it doesn't occur when I use my K-5II.
    BTW, the "1/200" speed depends on the focal length of the lens attached. If I mount my FA 77/1.8, the slowest shutter speed possible becomes "1/100s".

    Note: One may have to set the ISO setting to a high value in order to see any other shutter speeds than the longest one allowed by the camera (e.g., 1/200 in the above case).

    In conclusion, I can't see how this is a V6II bug.
  • Thanks @Class A for testing a similar setup on your K-1.

    Hopefully Ricoh Pentax can provide a fix soon.
    Antonio Lao
    Brand Manager
    _____________

    To help us better help you, always state the exact firmware version installed on your Cactus device(s), such as: "1.1.013", "NIK.A.001", "v.103", or "A06".

    TTL or HSS not working on Cactus V6 II and V6 IIs? Be sure to check hot shoe connectivity by doing the <CAMERA INFO> check.

    Feel free to suggest an improvement or share product ideas. Contact us directly at info@cactus-image.com.  At Cactus, we listen. 
  • Antonio said:

    Hopefully Ricoh Pentax can provide a fix soon.

    I don't think there will be a fix.

    According to another Pentax user the behaviour of the K-5 II is considered to be the "buggy" one while the K-1 behaves as intended (no proper P-TTL support for non-AF lenses).

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