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M and A lenses with HSS flashes on K1

sebas77
Posted 09/04/2017 - 23:03 Link
Hello,

today I found out that M lenses do not work with HSS flashes, fair enough. Side question: on my K1 the Pentax M 35mm stays always open at 2.8F is that normal?

Main question: I tried an A lens as well, it worked fine, but only in M mode. in A mode instead it was always setting the speed shutter either to 1/200 or 1/8000 nothing else. The lens is a Vivitar 105mm series A but it should not matter.
JAK
Posted 10/04/2017 - 00:11 Link
Have you got 'use aperture ring' enabled in the menu options?

Use the green button for metering to set the shutter speed (its in the camera manual!)
John K
nocturnal
Posted 10/04/2017 - 00:27 - Helpful Comment Link
To your first question:

M (Manual) lenses have no auto-aperture control as instructed by the camera, the next generation A lenses have this capability. With M lenses you twist the aperture ring, to say, F8, and the camera should stop the lens down to F8 just before the shutter opens. The K1 has an aperture lever I imagine, I own a K30. If it doesn't stop down your Pentax-M 35mm, the lens has aperture blades that are stuck open, won't close down, and these were notorious for this problem (I own a good version). Take the lens off the camera and gently operate the little lever with your little finger, the blades should 'snap' open and closed in a flash (turn the aperture ring around to f22 first). There should be almost zero friction.

2nd question:

Did you set the lens to the A setting on the aperture ring? Does it have an 'A' setting on the aperture ring? Do you mean Av mode on the camera? 'A' as in Pentax-A lenses can work with every mode on the camera.

There is a setting in the K30 camera menu called something like 'Use Aperture Ring', you need to set this to yes. I can't check as my battery is flat.

I think you mean Vivitar Series 1.

Is this your first Pentax DSLR? A K1?????
"In a photographic context I don't like the use of the word 'shot' as where I live this word refers to an extreme act of violence and not the beautiful craft of photography"
Edited by nocturnal: 10/04/2017 - 00:30
sebas77
Posted 10/04/2017 - 08:04 Link
Thanks for the answer,

about the M you are right, I forgot to step down! It's a long while I didn't use the M lenses and I forgot that the it was needed to press the green button first. To be honest is not very intuitive

about the A instead, it's not that obvious. The ring was obviously set to A and yes I meant the aperture priority mode on the camera. In this case it seems a bug to me. I didn't mention that I am using a Metz Af-2. I just tested again to confirm, while in Manual mode I can use HSS as intended, in Aperture Priority mode the shutter speed is always set either to 200 or 8000. Did anyone experience that? Is it a known problem?
Edited by sebas77: 10/04/2017 - 08:29
McGregNi
Posted 10/04/2017 - 08:58 - Helpful Comment Link
High speed sync flash is only compatible with M, Tv or Tav camera modes (i.e those where the time value can be directly input). In my view M is the most intuitive and practical working mode for HSS operations.

Be aware that HSS is generally a subset of P-TTL flash mode, and P-TTL is only compatible with autofocus lenses ....therefore good exposure control with an A type lens should not be expected. However, mechanically, everything should work ok with the aperture ring set to the A position, and you may find that HSS exposures are ok, but not as consistent as with an autofocus lens.

With older, M or K type lenses, then use either Auto (thyristor) or Manual flash modes. HSS will not be available, unless you use a flash where manual HSS is possible.
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver
Edited by McGregNi: 10/04/2017 - 09:04
sebas77
Posted 10/04/2017 - 09:04 Link
Thanks McGregNi, the only mode that would have made sense to me was the Av for HSS, but since you are very likely correct, I guess I have to stick with the other modes. Is there a way to use the green button and meter without changing the aperture? Otherwise the only option is to see the exposure through the view finder.

I will try the exposure. I was thinking to buy a samyang 85mm, but HSS is quite important for outdoor portraits. I am starting with those, but since my budget is limited, I want to invest on the right gear (btw I think I have to buy a cactus trigger as well, I will look up for those)
Edited by sebas77: 10/04/2017 - 09:18
McGregNi
Posted 10/04/2017 - 09:15 Link
I don't find that Av makes sense for HSS, because the exposure time ('shutter speed' ) is critical to your control over the background ambient brightness. So I find it's good to have direct control over that component with one e-dial ....generally we want to fix the ISO at 100, set a wider aperture for a nice portrait with background OOF, then juggle the shutter 'speed' to control the background exposure.

You could get Cactus V6II triggers to use with a P-TTL flash for HSS, or add in a Cactus RF60 flash or 2 .....but flash exposures will be Manual mode only. You will be able to remotely control the flash power but it's one extra thing to juggle during HSS operations.

Here's a link to an HSS demo thread on this forum showing the practical steps with photo examples ....

link
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver
Edited by McGregNi: 10/04/2017 - 09:16
sebas77
Posted 10/04/2017 - 09:22 Link
yeah I see what you mean, it's actually a normal use case, you want to be able to control the ambient light so it's even one stop less than your flash light. I was thinking to do it automatically though (using an exposure correction of -1), but I guess I can live with the exposure bar inside my view finder, otherwise how do you check if the ambient light is good enough?

Thanks for the link, I will do some research and come back to ask more questions in case.
McGregNi
Posted 10/04/2017 - 09:41 Link
I think it's just that when you're actually actively managing the balance of exposure between elements of your image, which is what we're doing with a flash-lit subject and ambient natural light in behind, that it needs that even more exact and direct hands-on control of manual mode.

Of course this applies just as much to non-HSS work as well, wherever we need to balance these two components of exposure in the same scene. It's just that for HSS those modes are 'mechanically' a requirement to actually get the shutter speed under control.

Here's another link to another thread I did covering a non-HSS situation, balancing indoor ambient light with bounced P-TTL in the pub.....

link
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver
sebas77
Posted 10/04/2017 - 13:42 Link
is the HSS more reliable with an autofocus lens because the flash knows about the focal length used or are there other reasons?

I don't think I will ever use a double light setup outdoor, but just for knowledge, how does the HSS work in this cased? Apparently the metz can work as HSS slave, but not as HSS master. Can the cactus control more than one flash?
Edited by sebas77: 10/04/2017 - 13:47
McGregNi
Posted 10/04/2017 - 14:36 Link
There's almost no known documented technical details on the P-TTL metering system, but the information used to help the pre-flash determine correct flash exposure includes aperture, ISO, focal length and active focus points. The pre-flash fine tunes this by taking into account the amount of light reflected back through the lens. Some of this information depends on contacts passed through the mount from autofocus lenses, so for that reason manual focus lenses are not compatible with P-TTL, or the subset functions of that mode (such as HSS).

The Cactus system can remotely control the power of P-TTL flashes, and you need one unit for the camera hotshoe and one for each flash. In the case of Cactus's own RF60 flash then the radio receiver is built into the flash, so no receiving V6 is needed. Remember this is a system for manual flash power only, including for HSS working. If you want radio triggering for HSS then you need the V6II units ..... the original V6 does not support HSS.

Here is a link to a demo thread I made showing traditional Optical triggering with HSS using 2 Pentax P-TTL flashes and a Cactus RF60 ....

link
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver
Edited by McGregNi: 10/04/2017 - 14:37
sebas77
Posted 10/04/2017 - 15:07 Link
I also quote this old post of yours:

Mark, regarding the Av mode and using AE-lock ... this does seem to work, and I suppose could be a practical way to get a quick, say one-off HSS flash. In general though I find manual working with the green button for metering the ideal practise.

if this is true, I will try it. To be honest I still prefer this idea to the use of M, this because I am sure about the aperture I want and I want to control only the time manually. if I use the green button in M mode, the camera will also set the aperture, which I don't want to change instead. Am I right?
McGregNi
Posted 10/04/2017 - 15:25 Link
At the time that response was written I thought the Av with AE lock to be a fiddly way of doing it, and I still think so. Av mode is for situations where the aperture is your 'priority' and the shutter speed can vary for correct exposure, given your exposure compensation setting. With HSS working the shutter speed affects both the ambient exposure AND the flash power needed. For precise control of all factors and for the fine tuning adjustments needed then M mode gives you it all.

I think the exact parameters that change with green button presses in M mode may depend on a custom setting ...('Tv shift' comes to mind) , but hopefully another member can advise more about this as I'm not really sure ......I find a quick point of the camera to the sky or bright parts of the background, press of green button, then tweak of aperture and shutter to get the DOF and brightness needed is a good way to control things. Having everything remain fixed until you specifically adjust anything again is a plus also I think.

And also I would avoid auto-ISO for all flash work .....choose a fixed ISO, and for HSS it's difficult to recommend anything other than ISO 100.
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver
Edited by McGregNi: 10/04/2017 - 15:26
sebas77
Posted 10/04/2017 - 15:31 Link
yeah sorry you are right! I just need to find a way to use the green button in M mode in such a way it won't change the aperture, if there is this mode.

ISO is fixed to 100 in outdoor for me
Edited by sebas77: 10/04/2017 - 15:31
McGregNi
Posted 10/04/2017 - 15:37 Link
Maybe we don't need to use the green button ...? It is really a way to reset parameters to their default positions. In this case of ambient light metering in M mode that will probably just be the 'program line' defaults .....but I hope someone with more knowledge of this sort of camera feature will help here.

You might be able to just point the camera, half press with the shutter and adjust from there. It may be that the settings in M mode will stay where you last left them if you don't press the green button. The green button is a good way to get straight back to a start point when things have gone astray.
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

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