Alpha 700 in "studio"

[Jonathan K]

Hi there,

I recently took some "studio" (if you can call my mess that way) shots with the A700. I really enjoyed the remote control, the AF illuminator... It works great.

A few things:
- why does the AF illuminator only work with the central AF sensor? In my situation (self portraits) it would have been great to use one of the other ones...
- the rendering of low key pictures on the screen of the A700 is not "correct": They look much brighter, they actually look like DRO+ level 5 shots. It made me change my settings a few times before I noticed that the files were ok. Did anybody else experience this?
- I also have the impression (it is only an impression, nothing solid) that the inbuilt flash fire used to control the WL flashguns is much brighter than with the 7D: On the one hand, it works much better (further away) but on the other hand it lights up the scene more when doing the kind of low key work I did.

Any ideas?

Thanks,

Cheers Jonathan

[David Kilpatrick]

I can't answer as to why the illuminator limits AF to the centre spot, I wasn't really aware that it did, but it's probably just because it works with all lenses including extreme wide angles, and the edge sensors might be beyond its field.

The brighter illumination of the wireless flash sounds likely, as my A700 will control wireless flash units beyond the stated distance in large, light-absorbing rooms. Since this happens before the exposure, it has no effect at all on the shot, but I guess you might blink more readily.

David

[Dr. Harout]

...why does the AF illuminator only work with the central AF sensor?

I didn't know about that too, and i think it's a great thing.
And I thought I knew everything about A700

[Jonathan K]

.... , and i think it's a great thing.
And I thought I knew everything about A700

Hi Dr Harout,

I would prefer all to work with AF light...

Jonathan

[Jonathan K]

Hello David,

are you certain that the preflash in WL (from the inbuilt flash to trigger the flashguns) does not affect the lighting at all? I experienced it differently:
First I noticed a shade behind the subject which had to come from a frontal flash. Since there was no flashgun in front of the subject, it could only have been the inbuilt flash. I removed the shade by putting an improvised diffusor on the inbuilt flash...
Then, I tried it out: I put the camera in WL mode and switched off all external flashguns. In that case the picture should be black, but there is a (small) quantity of light left over, not enough to light the scene correctly, but enough to influence the lighting.
I should add that I shoot at 1/125 or 1/60 of a second, due to the fact that the Minolta flashguns are less powerful than studio flashguns... and I usually want something like f8. But I didn't find a huge difference between 1/125 and the actual flash X-sync speed of 1/250 of a second. There is always a certain amount of light present... maybe a leftover of the preflash or something.

This is the only little gripe I have experienced so far with the otherwise unbeatably straight forward and user friendly Minolta WL flash system in comparison to a real studio flash gun system, triggered by a radio transmittor.
Or is it just an impression?

Jonathan

[Alain]

Hello David,

are you certain that the preflash in WL (from the inbuilt flash to trigger the flashguns) does not affect the lighting at all? I experienced it differently:
First I noticed a shade behind the subject which had to come from a frontal flash. Since there was no flashgun in front of the subject, it could only have been the inbuilt flash. I removed the shade by putting an improvised diffusor on the inbuilt flash...
Then, I tried it out: I put the camera in WL mode and switched off all external flashguns. In that case the picture should be black, but there is a (small) quantity of light left over, not enough to light the scene correctly, but enough to influence the lighting.
I should add that I shoot at 1/125 or 1/60 of a second, due to the fact that the Minolta flashguns are less powerful than studio flashguns... and I usually want something like f8. But I didn't find a huge difference between 1/125 and the actual flash X-sync speed of 1/250 of a second. There is always a certain amount of light present... maybe a leftover of the preflash or something.

This is the only little gripe I have experienced so far with the otherwise unbeatably straight forward and user friendly Minolta WL flash system in comparison to a real studio flash gun system, triggered by a radio transmittor.
Or is it just an impression?

Jonathan

As I understand the system there a final "preflash" to trigger all flashes and that one will be visible (the shutter needs to be open).

[David Kilpatrick]

I suggest you try a single wireless and then two - there may be a difference in the control intensity. I've never had any visible shadow on wireless setups but if you are bouncing the wireless flash from reflectors/umbrellas I guess it could happen. Gary Friedman has analysed the pulses for the flash, and we printed an article but right now I can't find it as it predates my current file archive.

David

[HUM469]

Yes there is a possibility for the last pulse of the on-camera control flash to affect the exposure slightly or cast a shadow. The cheapest way to fix that is to go buy a cheap roll of 110 film, and then without exposing it, have it developed. With the blank negative film in hand now, cut one or two layers to fit over your on camera flash and tape them into place. The blank negative film blocks most visible light, but IR passes through like it was open air, and the IR is what your off camera flash units are controlled by anyway. I read about this on both Gary Freidman's site, as well as some mention I think on mhoner.de, but had already been using it because I keep a roll of developed 110 film around anyway. I have been using it for a couple years now sandwiched between a UV filter and the darkest ND filter I could find for IR photography with my Sony F-828. At about $2.50 for the film and $5 for the developing, I found this to be a much cheaper IR pass filter than the ones I could buy in the store! It' just a bonus that it usually works well for the flashes too.

[Alain]

Yes there is a possibility for the last pulse of the on-camera control flash to affect the exposure slightly or cast a shadow. The cheapest way to fix that is to go buy a cheap roll of 110 film, and then without exposing it, have it developed. With the blank negative film in hand now, cut one or two layers to fit over your on camera flash and tape them into place. The blank negative film blocks most visible light, but IR passes through like it was open air, and the IR is what your off camera flash units are controlled by anyway. I read about this on both Gary Freidman's site, as well as some mention I think on mhoner.de, but had already been using it because I keep a roll of developed 110 film around anyway. I have been using it for a couple years now sandwiched between a UV filter and the darkest ND filter I could find for IR photography with my Sony F-828. At about $2.50 for the film and $5 for the developing, I found this to be a much cheaper IR pass filter than the ones I could buy in the store! It' just a bonus that it usually works well for the flashes too.

Was the trick not using slide film? Slides are made to the "torture" of a projector.

[HUM469]

Yes, sorry. I thought I had typed it in as 110 slide film, sorry. I did use the term "negative" didn't I? Ah well, I am glad you knew what I meant!

[Jonathan K]

Thanks for the exotic tip,

I will certainly try that out.
Is there a reason (except price) that it should be a 110 film? Or did I get something wrong?
Couldn't it be a 24x36 slide film?

Thanks for your help,

Cheers Jonathan

[HUM469]

I suppose it could be anything. I used 110 because it was the cheapest I could find for the uninterupted area I got from it, and is thick enough for me to cut IR filters for other applications as well. Besides using it on my A700 built in flash, I also use it as a lens filter for my F828, as well as over the heads of some manual strobes for IR fill. If you will only ever need it for masking the on camera flash of the A700, then I suppose any other size you like.