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Comment by BigJacko posted on K-x Bulb mode write-time slow? at 16/07/2010 - 15:35
Took a bit of doing, because I still wasn't able to get the whole flash apart neatly (which is probably a good thing, actually, because I means I wasn't able to accidentally touch the flash capacitor and get a big zap!)
But with a fair bit of wiggling and prising, I was able to get the hotshoe base out, just enough to get a 25w soldering iron with a point-tip bit onto the pink and white wires. Desoldered them, swapped 'em over, and soldered them back on, then put the unit back together.
Moment of truth... and yippee! We have 'flash ready' light working on the K-x now. Seems to be perfectly normal - steady 'lightning' lamp in the viewfinder when the flash is charged and ready to fire, switching to flashing whilst it recharges. Nice.
Haven't quite worked out whether the 'P' line is doing anything useful, or whether the Pentax is actually 'saying' something down that line which the flash is interpreting (I guess it depends what the Pentax 'mode' commmands are, and I haven't found these out yet).
But certainly the flash works fine enough in M mode on the K-x. In fact, the shutter-speed automatically sets itself to .... 1/180!! Even though I can't normally dial that in! Go figure! But it means I can just set up an appropriate ISO and aperture f-stop from the scale on the back of the flash unit, and I get a nicely exposed shot with no blown highlights and a decent histogram.
Not quite sure whether Av mode is working right (in these low-light conditions indoors, it was offering a faster shutter-speed with the flash unit on and ready, than it did without, but it was still far too slow for a good exposure. Maybe I'd better read up Av mode + external flash settings a bit more before drawing a conclusion, though.
Thanks again for the help and encouragement. If nothing else, you've inspired me to get physical with the soldering iron!
Comment by BigJacko posted on Safe or no? Pentax K-x & Ricoh XR Speedlite 300P flash at 07/07/2010 - 23:03
HS is a special mode, it actually fires multiple flashes very fast continuously to evenly lit the whole sensor.
I believe it even times the flashes according to the shutters and how fast they move.
What I meant was is that 1/180th isn't a natural shutterspeed for the camera to come on since it use 1/3th of stops. Just set you camera on Tv or manual, you get 125 - 160 - 200, there is no way you can set it on 180.
So the camera need to know a flash is on the camera to make it stop there. Sadly I believe you've a dumb flash which doesn't tell anything against the camera so it won't stop.
The only way to get it then on 1/180 is the use the X-sync mode, that's the flash sync and set the shutter permanently on 1/180th.
It's the red X on the same dial where you find Av & Tv, ect.
Maybe if you get the ready signal working it might actually stop on 180.
What do you mean with the guidenumber and speed?
If you mean shutter speed then actually it doesn't have any effect at all on the guide number. If you mean ISO speed then a doubling in the ISO/ASA means a doubling in the guidenumber.
Thanks for the pointers... it has definitely made me think, and as a result, I may have cracked at least some of the problem!
Mmm ... I was tryping from (defective) memory. Just had a look. It is a XR Speedlite 240 - exactly as the manual on the Butkus site.
Conversely, I'm pretty sure that the Ricoh flash's 'Ready' indicator hitting the Pentax K-x's 'Mode' input probably won't hurt the Pentax, because (a) the voltage is only about 3v at worst, and (b) the Pentax probably won't take any notice of it, if the 'real' Ready input is inactive. And so far, I've not measured any voltage activity at all on the Ricoh 'P' contact which is touching the Pentax's 'Ready' input. I'm presuming (hoping) that the 'P' contact is actually FROM the Ricoh camera TO the Flash - in which case it'll be safe... but I can't be certain, yet! Hence the mild worry.
Cheers again for taking another look at your flash. Decent of you.
Comment by BigJacko posted on Safe or no? Pentax K-x & Ricoh XR Speedlite 300P flash at 07/07/2010 - 21:21
I think I may possibly have confused myself about the camera's 1/180th requirement - I went looking in the manual again, to substantiate what I thought I'd seen, and I can't find it again! All I can find is a reference to the built-in flash having a flash sync range of 1/180th and slower (my bold) and a reference to using the Pentax own-brand external flashes in 'High Speed' mode, which it considers to be speeds above 1/180th (and those proprietary Pentax flashes do this when they're in a special 'HS' mode).
So... I'm not entirely sure whether I was right about the camera's 'requirement' to sync at 1/180th, after all. Maybe the 1/125th that the flash is wanting, will do after all! I will, of course, give both a try and see what happens!
@Stefan - the Ricoh flash has an auto mode which self-monitors the light reflected back from the scene/subject, so I'm hoping it might still work at 1/180th. I probably won't be using the flash in its full manual mode, because it seems such a headache to work it all out! Apart from anything else, I can't work out what the Guide Number would be at some of the higher speeds that the Pentax K-x can do!
The Ricoh manual lists the follow film speeds and guide numbers:
Film speed - Guide Number (m, ft)
25 - 15 (49)
50 - 21 (69)
100 - 30 (98 )
200 - 43 (141)
400 - 60 (197)
1000 - 95 (312)
The problem I have (apart from my own ignorance and stupidity, no doubt!) is that I can't work out what the Guide Number would be at, say, ISO 800, 1600 or 3200. The GNs don't seem to double as the film speed doubles, and (despite having played around with the numbers in a spreadsheet), I cannot work out what the mathematical series is!
So - the Auto mode looks like it will have to do for now (if it works). The Ricoh purports to 'beep' if it gets enough light, but I'm not qiute sure how it can know that the film/sensor is also getting enough. Even the auto mode requires the lens aperture f-stop to be set according to a table (which also doesn't go quite fast enough, but I reckon I can wing this one more easily). It shows:
Film speed (ISO/ASA) - F-stop
25 - f2.8
50 - f4
100 - f5.6
200 - f8
400 - f11
1000 - f16
I'm reckoning that at the higher speeds (3200, 6400 and 12800, we're talking f22, f28 and f32 or thereabouts! Even I can guess those from the preceding sequence! At least, I hope I've got that right!
As for Stefan's idea of swapping the hotshoe contacts around - that's next on my agenda (I mentioned in my first post that I was considering it). Unfortunately, I can't seem to get the flash unit fully apart (I get the freeling I haven't yet found all the screws, or there's something hidden inside the hinge)... so there isn't a lot of room to wield a hot soldering iron yet! But once I've found out how to properly disassemble the flash body, I will give it a go!
And to Andrew - thanks for the update on using your 240P. I couldn't find this one at the Butkus manual site, so I'm not entirely sure whether this is the one with just the 'ready' contact, or the 'ready and mode'. They have a 260P there, and a straight 240 (with no P)... so I'm still playing a tad cautious (in case yours didn't have the 'mode' contact too - and that's the one which is worrying me most, at the moment) Any further light you can shed on your exact model (or the number of contacts it's got) would be really handy.
And do you see the 'ready' light in your K200D's viewfinder? If not, that confirms my findings about which side the 'Ready' contact is on, too. If you do, then I'm back to the drawing board!
Thanks again to everyone for all your input and advice. I'm feeling a lot safer about using it, and having a good experiment this evening when the light drops a bit!
Comment by BigJacko posted on Safe or no? Pentax K-x & Ricoh XR Speedlite 300P flash at 07/07/2010 - 19:37
@Stefan - the hotshoe contacts are in the same places, yes - but only the back two make contact on the flash unit. Worse, they appear swapped: Ready and (presumably) Mode. I'm guessing it probably won't matter... but I'm wondering whether I should shield them, just in case.
I'll confess that I *have* already given it a try, and it seems to work. At least, it'll flash, and the camera hasn't blown up yet. I'm not entirely sure whether it's working correctly, mind - possibly I haven't set the sync shutter speed right? The camera seemed to want 1/180th sec, and the flash manual talks about 1/125th, so I'm not entirely sure what to use! It's been so long since I've used that flash (and it used to work at 1/125th on my old film SLR, I think).
The other mildly annoying thing is that the K-x can't tell when the flash is fully-charged - but I guess that's down to the 'ready' line being on the wrong contact on the hotshoe. It's no biggy - but it does mean I have to keep taking my eye away from the viewfinder in order to check the ready lamp on the back of the flash itself.
I can live with that - as long as it's not going to do any major damage in the long run. My gut tells me it's *probably* okay... but having just bought the camera, I'm loathe to cook it already!
Thanks for the input, guys. Of course, if anyone's got any further input, advice, warnings or solutions, please do let me know! I'm all ears!
Regards
Neil
Comment by BigJacko posted on Safe or no? Pentax K-x & Ricoh XR Speedlite 300P flash at 07/07/2010 - 10:27
Ta for the headsup.
Comment by BigJacko posted on K-x owner joining at 04/07/2010 - 21:40
I'm hoping the flash-gurus here can shed some light (ho-ho) on a compatibility issue I'm having.
I've got a 20-year old Ricoh XR Speedlite 300P flash unit which was great in its time - 0-90 degree tilt, auto/manual mode, low/high power modes, etc. I'm loathe to simply bin it, even though it is old, and I doubt it has much resale value.
Meanwhile, I have recently bought a new Pentax K-x dSLR with which I am in love. Its on-board flash does plenty of good work, but I'm still keen to know whether I can safely use my Ricoh flash too, for those occasional moments when I'd rather bounce a flash off the ceiling than point it in someone's eyes. You know the drill, I'm sure...
Trouble is, despite emailing the supposed Ricoh UK official source, as guided by the Ricoh website, I cannot find out the hotshoe pinouts, nor can I get them to commit to answering whether it would even be safe to connect to my Pentax K-x. The best they'd offer by way of advice is to tape over all but the centre pin connection. They couldn't, however, even tell me what those connections were on the Ricoh unit (despite repeated asking in various different ways) - so I'm assuming they've lost the service manuals/design blueprints way, way down the back of the sofa, or they just can't be bothered to go looking for a 20-year old bit of paper in a drawer somewhere. C'est la vie, I guess.
I have managed to find some useful info by myself and on the net, but I'm still no nearer a real answer.
http://www.bdimitrov.de/kmp/technology/hot-shoe/index.html tells me the Pentax hotshoe pinouts are (excuse the mis-aligned ASCII drawings, please):
(Lens-mount side)
X --- Trigger
x x
^ ^
| Ready
|
Mode
And by measuring (with a voltmeter) the signals on my Ricoh flash, I've deduced the following:
(Lens-mount side)
X --- Trigger (5.9v when fired/charging, down to 4.9v when charged)
x x
^ ^
| Not sure - zero volts at all times, seemingly. Poss XR auto/mode?
|
Ready (2.9-volt when charged, 0-volt when discharged)
As such, looking at all the above, I *think* the flash is basically safe, in terms of 'zappable' voltages (sub 6v on the trigger is okay for pretty much all dSLRs, from what I've read). However, I'm not sure whether the other two contacts being 'backwards' are likely to cause (a) operational problems (b) damage over the longer term.
I've even considered opening up the Ricoh flash unit and swapping the wires to the two Ready and Unknown contacts (they're just soldered on to a board the other side of the hotshoe base) - but I'm not sure if this is a good idea until I definitely know what the unknown pin does.
Does anyone have any advice/experience here that can help me? I'd be indebted to you, if you do.
And would you:
(a) bin the flash and buy a new one (in which case, replacement recommendations would be great, thanks)
(b) use the flash but only as a remote slave unit (in which case, what recommendations have you for how to connect it to the Pentax K-x & trigger it?)
(c) sell the flash on Ebay (in which case, what's it worth, do you think?)
(d) give the flash to a charity shop
(e) part-exchange it for some candles and a box of matches.
(f) none of the above - insert inventive and humorous solution here!
Thanks in advance for any and all ideas!
Regards
--
Neil
Comment by BigJacko posted on Safe or no? Pentax K-x & Ricoh XR Speedlite 300P flash at 04/07/2010 - 21:38
Just thought I'd say hi. I've just signed up, thanks in part to having already received indirect help from robbie_d who (without knowing it) tipped me off about a place that I could buy a replacement focussing-screen for less than the price of an arm and a leg! Yup... first day I got my brand-new K-x, I found dust on the 'wrong side' of the screen, and decided to remove it, and blow it clean. Followed a very useful video tutorial on YouTube, and got it clean, sure... but slipped at the last moment, and touched it with the lightest of touches with my jewellers screwdriver, and put a nice little hooked scratch on it! It sticks out at me every time I used the viewfinder, shouting "you're an idiot!"... so I just had to get a new one - but I wasn't going to pay 40-50 quid or whatever! £16.88 will do me just fine (assuming it arrives, of course!) And I'll know better next time, and I'll just live with the dust!
I used to have an ME Super... many many years ago... but due to a drunken evening in a pub, I no longer possess this, nor the 50mm prime that came with it. Some lucky person probably bought it off a landlord real cheap. Moral of the story is: check you're carrying the same number of bags on the way out, as you were on the way in! Gone in 60 seconds - no joke!
It's been 20 years since, and in the meantime, I'd given up my Ricoh KR10M (replacement for the ME Super), and all but forgotten the joys of SLRs since owning a succession of digital compacts.
But I went out shopping (ostensibly for a Canon 450D that I saw in a shop window and liked the specs on), and got convinced by a shopkeeper in a different shop, that my old K-mount lenses (a Tokina 80-200 f4, a Vivitar 28mm f2.8, and Rikenon 50mm f1.7) would still have a use on the new K-x, and I wouldn't have to throw them out (they're worth zilch on p/x). I liked the sound of that - and he wasn't wrong (although they don't work *quite* as easily as I'd hoped, to be honest).
Certainly, I am extremely happy with my K-x... and it has rekindled my dormant love of photography. So much fun learning 'the new ways' with dSLR... and the joy of having 'ISO choice' on the fly is fabulous!
My last quest is to find out whether my Ricoh XR Speedlite 300P flash can safely be matched with the K-x. I asked the Ricoh UK main-dealer (via the Ricoh site), but they were both non-committal and a tad clueless on the specs - suffice it to say they advised me not to use it because they 'couldn't be sure'. Since then, I've looked around for other advice, and found nothing that says "don't", and found pinouts that suggest it might be okay. Anyone else got any ideas?
Anyway - thanks for a great forum. Hope to keep learning, and keep enjoying my new K-x. Pleased to meet ya...
Regards
Neil
Comment by BigJacko posted on K-x owner joining at 04/07/2010 - 16:59


I've been messing around with Bulb mode on my new K-x (thanks to me managing to turn a 'One-for-All 6' TV remote control handset into a suitable trigger, via its JP1 socket, a PC, and some free software. It'll do until the UK sees some more stock of the genuine Pentax Remote Control F unit!)
I've noticed that whenever I take a photo in Bulb mode, there is a very long wait after I've closed the shutter, while something is happening. During this time, the camera is, to all intents and purposes, locked up. The power light stays on (blue), but no buttons elsewhere will do diddly-squat. Eventually, the 'writing to SD-card' red-light flashes; the image just taken is 'previewed' for 1 sec on the LCD; and all is well again, and I can carry on and take the next shot.
Initially, I thought something was bust. I even must've wasted a couple of good shots because I freaked out and turned the power off (losing the photo in the process), thinking that the camera had locked up due to dying batteries or something.
However, now I'm a bit more accustomed to it. The lockout pause can be in the order of minutes, after a five minute exposure - but I'm more patient now.
But I would still like to confirm this is 'normal' behaviour for the K-x. I can find no mention of it in the manual, or anything that might suggest Bulb mode involves a long wait while it's doing its thing.
And does anyone know what is the 'thing' it's doing, for so long? Just curious...
Thanks in advance.