Strobist 101

Hello folks

After recently getting a K-5 I have been playing with flash for the first time; I have an old Cobra Pentax flashgun in the house back from my dad’s film days. I have been using this on camera, bounced off walls or the ceiling and have been impressed with the extra pop in my images.

Reading up a bit more and going on the strobist blog, I have been keen to get the flash off camera and so have bought a Nikon SB-28 as they seem to be highly regarded and have full manual control and a pc socket that my Cobra is lacking and also works really well in A on the K-5.
I have a few very basic questions...

I want to get a pc cable to go from the K-5 to the Speedlight – do I just need a standard male to male pc cable? (this seems to be the case although many of the longer pc cables I have seen seem to be male to female?)

Still don’t understand the A setting on the flash, it seems that to get the correct exposure the flash only needs to know the ISO and the aperture of the camera, but not the shutter speed – how can the flash expose properly without this, can someone explain this one to me?

The new flash has a multi flash mode where you can tell it to fire x number of times and the speed to repeat the flashes, which looks cool, but is there any use for this apart from the obvious multiple exposure effect from a moving subject?

I have been looking at wireless triggers as a possible future purchase (I have seen the Cactus models recommended on here) but was also thinking that just buying one of the wireless capable flashes such as a Metz may be the easier option – how does the wireless in the K-5 work, is it infrared as with the Canon system or does it work on RF like the Cactus triggers, is there any reason to get the cactus triggers over the inbuilt wireless of the K-5? (for amateur use, nothing too advanced – mainly concerned with portability and ease of use)

Finally, I have gone through a couple of sets of batteries so far and was thinking of picking up some rechargeables – can anyone recommend some good cheap ones for use in a flash?

Thanks!

In relation to the flash question and shutter speed. Shutter speed has no effect on your flash. However, on a K5 your max sync speed will be 1/180.

The thing to remember is, aperture affects flash, shutter speed controls ambient light.

Wireless: you can use your built in camera flash to trigger a compatible off camera flash, I don't know what kind of range you will get as I personally use triggers. Some flashs can be used as triggers ( master controler) to trigger other compatible off camera flashs but you will need to check which do and don't.

Trigger wise there are a lot of choices, I have been using Aperture Trigmaster Plus triggers for a while and can report that they are very good. I have just ordered a set of Phottix Strato triggers as they have a TTL pass through feature which I will find very useful, I think Phottix are the only people who currently provide this feature unless you buy top of the range Pocket wizzard which is not currently Pentax compatible.. I could go into why TTL pass through is so good in a lot more detail but not in this post.

From what I have read the Phottix Strato triggers would provide you with reliable triggering, good build quality and idiot proof simplicity in terms of usage. The C6 canon version is compatible with Pentax. You can find the Phottix web store online if you type it into Google a set will cost you about £55

A really good starting point for anything flash and off camera flash is the Strobist web site.

Hope this provides some light.

Fletcher8

By digital pulses of the flash itself - so purely optical.

Therefore range depends on conditions. Indoors it's not a problem. Outdoors I've managed two or three meters in shade.

The dedicated Pentax wireless flash (with compatible flashguns) will handle full P-TTL, and HS sync (for daylight fill in). But be aware that daylight HS P-TTL wireless flash will require two compatible guns - one as the master/controller on the camera and one (or more) as slaves.

I use the Cactus v4 and they work very well indeed, and provide other lighting options that do not require line-of-sight (like flashguns behind walls, inside cupboards etc )

Shameless plug: You'll find my ebook helpful

Matt

fixed it 4 u

You have an ebook now? Another vote for Cactus, but the updated V5 here.

Thanks all for the illuminating responses!

The Phottix Strato triggers look great for the money and haven’t heard of them before, even now can’t really find any reviews in regard to using them with Pentax, if they work well seems a great alternative to the Cactus V5s at a similar price point but with TTL functionality – wonder why more aren’t using them?

Matt nice point about the need for more than one flash for off camera HSS, as this was one of the reasons for considering the dedicated TTL flash, I guess this is due to the internal flashes inability to sync at high speed, I also assume this means that the PC port wont sync at high speed, so the only way to achieve high speed sync off camera is with two expensive flash units, looks like I will be looking for some ND filters for the short term, Pentax need to up their game in the flash sync department, ironically I used to own a Nikon D40 (entry level camera) which would sync at 1/500 and never thought anything of it!

So have just ordered a PC sync cable and going to look at getting some remote triggers in the not too distant future, as I don’t think the dedicated flash is going to be the fix all that I originally thought, Fletcher8 would be great if you could let us know how you get on with the Phottix triggers when you’ve had chance to use them, as it looks to be a toss up between them and the Cactus V5s – I assume they will work with the old Nikon Speedlights in manual too, maybe not??

Best,

Paul

Paul as soon as the Phottix Stratos arrive, anytime now, I will post my findings within a week and let you all know how they compare to previous triggers I have used. The one area I am really interested in is the TTL pass through feature.

Fletcher8

You are correct

What is not apparent is the fundamental technical difference between 'regular' flash and HS. Regular flash works like this:
* Mirror up
* Leading curtain of shutter opens all the way
* Flash fires, then shutter delay (i.e. Tv)
* OR Shutter delay, then flash fires (in "Slow" flash mode)
* Trailing curtain closes
* Mirror down
* Both shutter curtains move back to starting positions

With regular flash it only works because the whole sensor is exposed when the flash fires. That's why you're limited to 1/180s


With HS flash mode, the trailing curtain starts moving before the leading curtain has reached the end of the travel. Essentially with shutter speeds faster than 1/180s there is a 'slit' progressing across the sensor. If a regular flash went off (say at 1/4000s) then you'd have a sliver of light across the frame and the rest would be dark.

HS works by 'machine-gunning' the xenon tube to pepper light as the shutter slit moves across the frame.

That's why you need two expensive guns! (FWIW, originally the *ist-D could do HS mode from the pop-up, but apparently this wasn't possible in later bodies as the power requirements mess up SR - among other things).

Soooooo, ND filters can be useful

Indeed
See here

Thank you Don for 'upping' the shameless plug!


Matt

Perfect thank you!

The more I learn of HSS the less use it actually seems to be, as I understand this "strobe" will also significantly reduce the power of the flash output, still not sure why Pentax can't offer the same 1/250 x-sync as with the competition though.

Thanks for the detailed response!

There are ways to use HSS on flash's that don't support it but how good it works depends on the flash, studio lights tend to be ok since they have long pulse durations.. speed lights not so much but I did manage to pick up the flash from my metz af50 at 1/8000 although it was very dim.

Doing this requires that you have some way of ignoring the pre flash optically (the metz can do this) and you then use your strobe as a normal light that is affected by shutter speed.

I've seen people use this to good effect using AB's in the states to freeze action and over power the sun but as with any hack its sort of limited.

As for radio triggers I got one that came with my Lencarta studio lights and I've never had a problem with it indoors (I'm guessing its based on ebay triggers) and I also have some bowens pulsar triggers that have been doing me great out doors... I haven't tried the max range on them but they always seem to fire.

The radio triggers I'm really interested in is the new pocket wizards that give you control over 4 groups, I would love the ability to turn strobes off/on using the trigger (if I could adjust the power even better). I'm not a fan of P-ttl since I cant seem to get it to do what I want (when trying to be creative) but with manual flash's its very easy .

Phottix Strato triggers update!

Ok the bad news first, the TTL pass through does not support P-TTL, although TTL does work from the triggers hot shoe. OK now the good news, the Strato triggers work flawlessly, the range is over 100 meters and from my tests the channel selection settings all work fine. There is an option to fire all channels at once which I think is a good feature. Anyway, the build quality is first rate and all of the accessory leads are also first rate. If you order direct from the Phottix Web Store you will save roughly £35 compared to buying from a UK supplier. These triggers are very, very good, I just wish they could provide P-TTL pass through, but I guess you can't
have everything. I have emailed Phottix with a request for P-TTL, I will just have to keep my fingers crossed.

So am I right in thinking that there are no flash triggers that support P-TTL?

Available soon AK-TTL Radio Wireless TTL flash trigger Pentax P-TTL and wireless HSS

Thanks for the update - shame these don't work as hoped, the AK-TTL triggers sound promising though outside my budget - seems the cactus v4/5 triggers are still the best bet for wireless on a budget with Pentax