Go Back   Steve's Digicams Forums > Digicam Help > Flash (External)

Reply
 
Thread Tools Search this Thread
Old Apr 25, 2011, 6:24 PM   #1
Junior Member
 
Join Date: Apr 2011
Posts: 7
Default Does the Sony a230 do a pre-flash through external flash?

Hi, I am a new member and have been reading posts on how TTL flashes work. My understanding is that a pre-flash will fire before the main flash to allow for correct exposure.
I do not know if my Sony a230 does a pre-flash with a new external flash I have, a Targus TG-DL80S that is dedicated for the alpha mount: http://www.targusdigital.com/product...rent_id=100056
I believe the pop up flash on the a230 does a pre-flash based on the specs from the Sony website: http://www.sonystyle.com/webapp/wcs/...specifications
However, the description for the pop-up flash for the a230 says “Flash Metering System : ADI flash (automatic change for Pre-flash TTL)” What does this mean, and is it only for the pop-up flash, or does it apply to any connected external flash?
I know the camera recognizes the Targus because there is a flash compensation setting in the camera that is accessible only when the flash is attached.
So how do I know if the camera is doing a pre-flash through the Targus flash? Thanks in advance.
Adam
schwizzle is offline   Reply With Quote
Sponsored Links
Old Apr 25, 2011, 6:34 PM   #2
Junior Member
 
Join Date: Apr 2011
Posts: 7
Default

Also, I am still very much a beginner when it comes to flash photography, so if anyone knows of any good beginner threads, please let me know.

Last edited by schwizzle; Apr 25, 2011 at 11:55 PM.
schwizzle is offline   Reply With Quote
Old Apr 25, 2011, 6:39 PM   #3
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

I've never heard of a Targus Flash.

But, yes, by default, you will have a metering preflash with digital when using a compatible external flash if it's dedicated to a given camera system (and the same thing is applicable to all major brands of cameras).

Older flash models don't understand the commands needed for a metering preflash (as used by digital cameras, since the reflective characteristics of the imaging sensors makes it too difficult to use other metering methods like off the film metering).

So, a Metering preflash is used instead with digital (measuring the light reflected from a weaker preflash to determine the length of the main flash burst needed for proper exposure for a given ISO speed and aperture).

ADI (Advanced Distance Integration) with KM and Sony dSLR models just adds the ability to take focus distance into consideration for flash exposure when using D type lenses. But, a preflash is still used with dedicated flash models.

Now, it is possible to get a flash that doesn't require a preflash. Older manual flashes won't use them. But, with most any dedicated flash system for a modern digital camera, a preflash is going to be used.

If you're not seeing a preflash from that Targus, then it's probably not compatible with the camera. Sometimes you do see flash systems that were originally designed for film cameras that don't understand the commands for a preflash, and sometimes they're advertised as being compatible with newer digital cameras. When you get one of those, it will usually fire at full power only.

Hint... if you can see a flash through the viewfinder, you're seeing a metering preflash (because when the shutter is open and the flash is firing to illuminate your subject during the exposure, the mirror is blocking the light going to the viewfinder so that you can't see the flash being used for the exposure).
JimC is offline   Reply With Quote
Old Apr 25, 2011, 7:43 PM   #4
Junior Member
 
Join Date: Apr 2011
Posts: 7
Default

Thanks, I will give it a try later tonight and look for the pre-flash.
schwizzle is offline   Reply With Quote
Old Apr 26, 2011, 12:09 AM   #5
Junior Member
 
Join Date: Apr 2011
Posts: 7
Default

All right, tried it out, and I do see a flash through the viewfinder. Awesome! The paper that came with the flash said it would do a pre-flash and is full TTL, I just didn't know what to look for.
schwizzle is offline   Reply With Quote
Old Apr 26, 2011, 12:22 AM   #6
Junior Member
 
Join Date: Apr 2011
Posts: 7
Default

In case anyone wants to know where I got the flash from, it was new off of eBay for $70: http://cgi.ebay.com/TTL-Zoom-Flash-S...item53e694dc02.

I found another seller after that selling it for $65: http://cgi.ebay.com/TARGUS-TC-DL80S-...item53e6e66eef
schwizzle is offline   Reply With Quote
Old Apr 28, 2011, 7:14 AM   #7
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

From what I can tell from it's photo and specs, it's probably the same flash as the Vivitar DF-283. See it here:

http://www.vivitar.com/products/9/fl...807/df-283-son

It's manufactured under a variety of different brands names. I can't remember the "real" manufacturer (but, it's not Vivitar or Targus).

You see that kind of thing a lot in the camera industry (the same basic lenses and flashes being OEMd for a variety of different brand names, with only minor cosmetic differences between them).

It's one of the least expensive dedicated flash models you can find that appears to give reasonably good exposure with the Sony dSLR models. The Vivitar branded version of it (Vivitar DF-283) sells for around $89 at major retailers. So, $69 from an Ebay vendor sounds about right (especially since you're probably going to get better service and return policies from a retailer selling it). Here's one at B&H:

http://www.bhphotovideo.com/c/produc..._Series_1.html

But, it doesn't give you an Auto Zoom head (manual only), and it doesn't support HSS (High Speed Sync, a.k.a, FP Mode). So, you're limited to the x-sync speed of the camera if you want the flash to contribute to the exposure (1/160 second with your A230). They make a version with an Auto Zoom head with more power (Vivitar DF-383) that sells for around $129 at retailers. But, it doesn't support HSS either. I've also seen complaints about build quality/reliability. But, they do cost a lot less than most alternatives for a given power output.

Please let us know how it works (exposure accuracy, etc.) after you have a chance to use it more.
JimC is offline   Reply With Quote
Old Apr 28, 2011, 2:27 PM   #8
Junior Member
 
Join Date: Apr 2011
Posts: 7
Default

Thanks for the info Jim. One thing I've noticed about the flash is that the plastic lens on it is slightly yellowed. I haven't noticed it affecting the color of my photos, but I will do some more comparative shots after my semester is done.

You're definitely right about HSS not being supported. I only realized this after reading about the features for the Sony HVL-F36AM. I think I assumed that it would be a camera setting since the a230 does the rear and slow sync. Also, I don't think the Targus will be able to do wide angles very well because it doesn't come with a wide angle diffuser (and I can't find one for it).

I found a F36AM (w/case, diffuser, stand) on eBay used for a decent price, so I went ahead and got it. I'll do some comparative shots between it and the Targus within the next month. I'll either end up keeping the Targus as a backup, sell it, or (correct me if I'm wrong) I could use the Targus and the F36AM together by having the Targus on the hotshoe and then use the F36AM wirelessly. I don't know if this is called using the F36AM as a slave or not and will look for threads on slave flashes.

In checking for exposure accuracy and knowing how the flash works, again I'm pretty new to flash photography (and can learn more with photography in general), so is there a thread anyone could point me to that explains what to look for and how to measure accuracy? Thanks!
schwizzle is offline   Reply With Quote
Old Apr 28, 2011, 4:27 PM   #9
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

Wireless gets a bit complicated. Your A230's internal flash can control a compatible external flash (and you're limited to a single external group that you can fire with the A230's internal flash). But, I don't know if you could use a flash like that Targus in the camera's hotshoe to do the same thing or not, as you'd probably need a higher end flash that's designed to act as a master. You'd have to try it to find out.
JimC is offline   Reply With Quote
Old Nov 1, 2011, 2:10 AM   #10
Junior Member
 
Join Date: Apr 2011
Posts: 7
Default

Well, it's been a while Jim. And I really haven't tested out the Targus flash a whole lot. For what I did, it took good pictures, but I've done more with my F36AM.

One thing I'm looking to do is to use a flash bracket with the Sony flash. I have a Stroboframe Quickflip 350. I've been trying to find out to adapt the shoe of the F36AM to a standard ISO shoe and retain the wireless ability of the flash.

I ordered one adapter already, but it took away the wireless capability of the flash.

I have the idea to just get a 1/4" ISO adapter that could screw into the bottom of the stand for the flash and do it that way, or just get a washer and a 1/4" screw that isn't too long to secure the flash+stand to the bracket.

Do you know of any adapters that an alpha flash can slide onto, has the ISO standard shoe on the bottom to fit into the Stroboframe mount, but not cancel out the wireless function of the flash?

Or would it be easier just to get an off camera cable and forget wireless.....

Thanks.
schwizzle is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 5:22 PM.