All Forum Comments
Comment by Anvh posted on 360 FGZ under exposure on K10D at 03/11/2009 - 18:19
Comment by Anvh posted on Useless topic at 02/11/2009 - 23:44
Everyone has that problem so it's forum related so far as I know.
Comment by Anvh posted on EXIF details at 02/11/2009 - 22:31
Do you know what type of engine this is?
I know it's a multi-row 14 cylinder radial engine but from what manufacture?
Comment by Anvh posted on More cylinders! at 02/11/2009 - 20:52
Customers will receive their refund in local currency (Pounds for UK Customers….
This cashback is only valid for products which have been supplied and distributed within Germany,
Austria, Switzerland, France, UK, Ireland, Estonia, Sweden, Norway, Finland, Denmark, Spain, Italy,
Poland, Greece, Belgium, Netherlands, Luxemburg, Bulgaria, Romania, Slovenia, Czech Republic by
PENTAX subsidiaries and accredited distributors.
Comment by Anvh posted on K-x has arrived + cashback from 2nd November... at 02/11/2009 - 17:33
Also it seems you can order products from abroad and still use the cash-back, at least I can't find it anywhere where it says you can't do that.
Comment by Anvh posted on K-x has arrived + cashback from 2nd November... at 02/11/2009 - 17:17
And why do you hate that you aren't right now, it only makes life easier like you said
Comment by Anvh posted on Looking for a flash with an iluminated set up screen at 02/11/2009 - 16:15
What focal length and shutterspeed did you used, if I may ask
Comment by Anvh posted on Motorsport Shots at 02/11/2009 - 15:18
Or, to put it another way, Distance = GN / f-number, right?
So at ISO 100, a Guide Number of 48 at f8 would give a range of 6 Metres?
And if you use ISO 200 you will have a GN of 96 so you will have 12 metres.
Sorry it's still not clear in my mind.
The flash would have based it's exposure on the reflection from the 3M distance to the target.
Surely there must be drop off in light between the target and the camera which will cause under exposure.
Please be patient
Greg
I know it has to do with luminance, that is the key thing in all this but it's quite hard to understand that and since I'm not sure I understand it I can't explain it.
I can push you a bit in the right direction though.
Luminance corresponds to the total amount of light coming from a given surface area. Luminance, also called lightness or intensity, is used along with hue and saturation. It basically describes the amount of light that passes through or is emitted from a particular area and falls within a given solid angle. Luminance is an indicator of how bright the surface will appear.
Now since we talk about surface area, a surface will look smaller when distance becomes greater but the luminance or let's say lightness per square metres stays the same.
Since the surface becomes smaller the subject have less "power" to illuminate something, but we don't want to illuminate something with the subject but capture the luminance and like said before distance is not important for that.
Well you can say since the subject appears smaller, it needs to illuminate less pixels, and that would be the drop off then that you're seeking for. But the pixels will be illuminated just as bright if you stand 1 metre away or 10 metres.
I hope that explains it a bit
Greg,
I am not an expert on this and I have no complicated formula to present. And am rubbish at technical issues, the ones who top the scale on these aspects are experienced guys like Stefan and others as you see here, but if you want a simple straightforward way of doing it just slide all your setups into manual including flash and then try exposing from the distance you want the camera to be. Just use a rock or a dummy baboon if needed be to attempt some shots and try it and find the right settings. You will have much more control rather than putting your flash into AUTO. Its easily manageable, a few trial shots and you will have the subjects pinpointed accurately with that method.
I used to be afraid of manual settings until one of our most experienced members in the flash fields and not only, Mattmatic here convinced me that manual is the way to go. You should get one of his flash manual guides, its a must have aid for great exposures.
How do I know that? Many frustrating hours in the shed puffing coloured smoke and blowing bubbles got me there and now that's all I use, manual
AUTO mode do the calculation, this one to be exact Distance = GN / f-number and shows that on the back of the screen meaning you know what's going on without doing calculations for it. You still need to do everything by hand though.
You can of course play till you get it right but when time is short that's not always an option.
Comment by Anvh posted on Looking for a flash with an iluminated set up screen at 02/11/2009 - 11:47
And yes road dancer there is a formula.
GN = distance × f-number.
Normally GN is at ISO100 so if you double the ISo you will double the GN as well.
Comment by Anvh posted on Looking for a flash with an iluminated set up screen at 01/11/2009 - 21:51


The best way to solve this is to set the flash exposure in the camera self to the correct value, the camera keeps that in his memory so you don't need to set it up always that way.
I've my flash set to +0.7 others will probably have +0.5 or +1 so you really aren't the only one.