Re: Re[2]: Flash photography and *istD
On Tue, 2004-01-06 at 23:21, Bruce Dayton wrote: > > One interesting difference with the *istD (or any DSLR for that > matter) is that it has a narrower latitude than print film. Coupled > with the ability to quickly and cheaply test, more is explored on it > and it's behaviors than previous film cameras. One wonders if there > has always been a few exposure issues with flash systems that is > largely hidden by the latitude of print film. If you shoot slide film, there wouldn't be much difference with digital in this respect. -- Frits Wüthrich <[EMAIL PROTECTED]>
Re[2]: Flash photography and *istD
Hello Tanya, I think the jury is still out on this one. You have two different issues for the *istD. First is P-TTL. This is the latest type of TTL from Pentax. It was introduced when the MZ-S was released. This emits a preflash that is measured before the main flash. Supposedly it is more accurate and renders more natural looking images. Then there is digital TTL from the FTZ flashes (AF330FTZ, AF500FTZ) and analog TTL from the older (Af280T, AF400T) units. I don't know which one your Sigma's are, but if had to guess, I would think that they are digital TTL like the AF500FTZ. I haven't done enough flash stuff yet, nor seen enough on the web from others to make a good determination as to how well the flash system is working. One thing the AF360FGZ does with the *istD is high speed flash synch for daylight fill. The AF360FGZ can be programmed to compensate the exposure, so I normally dial in about -1 to -1.5 stops of light. So with that setup, you can shoot at ANY shutter speed up to 1/4000 in daylight and have the flash fill in the shadows a bit and put a catchlight in the subject's eyes. One interesting difference with the *istD (or any DSLR for that matter) is that it has a narrower latitude than print film. Coupled with the ability to quickly and cheaply test, more is explored on it and it's behaviors than previous film cameras. One wonders if there has always been a few exposure issues with flash systems that is largely hidden by the latitude of print film. -- Best regards, Bruce Tuesday, January 6, 2004, 12:36:56 PM, you wrote: TMP> On Tue, 2004-01-06 at 17:04, Heiko Hamann wrote: >> OTOH - you now can predict the TTL-behaviour of the *istD and use the >> ISO setting for flash exposure compensation ;-) TMP> Frits wrote: TMP> Yes, I thought about this as well, flash compensation is something I TMP> badly miss on my PZ-1, so now I have it on the *ist D. That would mostly TMP> be used for fill-in flash I guess. TMP> Yes, but you wouldn't NEED it if the TTL was working properly to begin with. TMP> This is quite a major consideration to me as one of the main reasons that I TMP> *want* to get the *istD is so that I have a compatible flash system to go TMP> with the body. I have been using the Oly with my Sigma 430st and 500st TMP> manually, and have been quite happy with the results, so if the *istD TMP> doesn't work properly in TTL, makes me wonder if I will race out and buy one TMP> as quickly as I thought or maybe wait for something *better* as I have been TMP> thinking of doing anyways... TMP> tan.
Re: Re[2]: Flash photography and *istD
On 6 Jan 2004 at 10:35, [EMAIL PROTECTED] wrote: > I have noticed that mine seems to expose differently depending on aperture - > from a distance of about ten feet, I used the FA* 24 f/2 and shot at a painting > in my bedroom. The smaller apertures showed a marked difference in exposure as > compared to the bigger ones. Try it without flash too :-( Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
Re: Re[2]: Flash photography and *istD
I have noticed that mine seems to expose differently depending on aperture - from a distance of about ten feet, I used the FA* 24 f/2 and shot at a painting in my bedroom. The smaller apertures showed a marked difference in exposure as compared to the bigger ones. This is using the AF500FTZ. I rarely use flash, so I did not follow up on this much, except to form the impression that the firmware is probably defective. I did send a comment/complaint to Pentax Cnaada, with so far zero response. Quoting Bruce Dayton <[EMAIL PROTECTED]>: > Hello Heiko, > > Thanks for the information. Certainly something for me to check out. > My own observations are thus: > AF360FGZ seems to slighly underexpose - sometimes when vertical > shooting with flash mounted in hotshoe it underexposes by quite a bit. > AF400T seems to overexpose by at least a stop. > > These are with ISO set to 200. I'll have to try 400 and see what > happens. > > Again, thanks for the info. > > Bruce > > > > Tuesday, January 6, 2004, 2:32:00 AM, you wrote: > > HH> Hi Bruce, > > HH> on 05 Jan 04 you wrote in pentax.list: > > >>Certainly an area that I am most interested in. I am not shooting > >>with the AF500FTZ. I have the AF360FGZ and 2 AF400T's and 1 AF280T. > >>Could you be a bit more specific about what your results are like? > > HH> There's a German thread on incorrect flash exposures at > HH> http://www.digitalfotonetz.de/phpBB2/viewtopic.php?t=4997&highlight= > > HH> A source at Pentax Germany has explained that there exists a problem > HH> with the TTL-metering (I only repeat some statements of the mentioned > HH> link): The TTL-sensor measures the light that is reflected from the > HH> CCD's surface. But it seemes, that the reflection of the CCD differs > HH> depending on the chosen ISO setting. The exposure will be correct only > HH> at ISO400 as the development and testing of the TTL-measurement was > HH> apparently made at ISO400, only. > > HH> At ISO settings below 400 the camera will under-expose, at setting above > HH> 400 it will over-expose. > > HH> This problem can probably not be solved by a firmware update as there is > HH> no upgradeble TTL-software but some kind of hardware solution. The > HH> problem does not exist if you use P-TTL. > > HH> I didn't try that myself (although I have an AF500FTZ I'm not a great > HH> flash user), but maybe this informations brings some light into the > HH> flash behaviour of the *istD. > > > HH> Cheers, Heiko > > > - This mail sent through IMP: http://horde.org/imp/
Re[2]: Flash photography and *istD
Hello Heiko, Thanks for the information. Certainly something for me to check out. My own observations are thus: AF360FGZ seems to slighly underexpose - sometimes when vertical shooting with flash mounted in hotshoe it underexposes by quite a bit. AF400T seems to overexpose by at least a stop. These are with ISO set to 200. I'll have to try 400 and see what happens. Again, thanks for the info. Bruce Tuesday, January 6, 2004, 2:32:00 AM, you wrote: HH> Hi Bruce, HH> on 05 Jan 04 you wrote in pentax.list: >>Certainly an area that I am most interested in. I am not shooting >>with the AF500FTZ. I have the AF360FGZ and 2 AF400T's and 1 AF280T. >>Could you be a bit more specific about what your results are like? HH> There's a German thread on incorrect flash exposures at HH> http://www.digitalfotonetz.de/phpBB2/viewtopic.php?t=4997&highlight= HH> A source at Pentax Germany has explained that there exists a problem HH> with the TTL-metering (I only repeat some statements of the mentioned HH> link): The TTL-sensor measures the light that is reflected from the HH> CCD's surface. But it seemes, that the reflection of the CCD differs HH> depending on the chosen ISO setting. The exposure will be correct only HH> at ISO400 as the development and testing of the TTL-measurement was HH> apparently made at ISO400, only. HH> At ISO settings below 400 the camera will under-expose, at setting above HH> 400 it will over-expose. HH> This problem can probably not be solved by a firmware update as there is HH> no upgradeble TTL-software but some kind of hardware solution. The HH> problem does not exist if you use P-TTL. HH> I didn't try that myself (although I have an AF500FTZ I'm not a great HH> flash user), but maybe this informations brings some light into the HH> flash behaviour of the *istD. HH> Cheers, Heiko
