braindead_fr3ak: The more you can zoom your flash, the less wide the flash, and the more power it can deliver. You can try shooting at 1/1 at both 24mm and 105mm and see which one is more powerful!

If you set to 24mm but your lens is at 50mm, then you are wasting the batteries and wide spread of your flash. Normally if you bounce flash, it is recommended to zoom the flash head a bit more (since bouncing makes the flash spread wider.)

Guide numbers are measured at F1.0 ISO100. The problem then is that different manufacturers specify at 35mm, 50mm or the longest flash zoom. Another problem is that some prefer to count in meters, some in feet.

A proper Guide Number specification should sound like:

42 meters at F1.0 ISO100 with flash zoomed to 105mm

Not "98", which can mean anything. 98 feet at F1.0 ISO100 with flash zoomed to 35mm is not a direct comparison!

I cannot find out the actual guide numbers at 35mm or 50mm as many sites have this information in a very inconsistent manner.

The SB-600 is rated 98 feet at 35mm ISO100. That's 1176 inches or 29.87 meters. This is about the same as the HVL-F42AM:

Sony HVL-F36AM = 36 meters at 85mm
Sony HVL-F56AM = 56 meters at 85mm
Sony HVL-F42AM = 42 meters at 105mm, 30 meters at 35mm
Sony HVL-F58AM = 58 meters at 105mm, 38 meters at 35mm
Sony HVL-F20AM = 20 meters at 50mm

Nikon SB-600 = 30 meters at 35mm
Nikon SB-800 = 38 meters at 35mm
Nikon SB-900 = 34 meters at 35mm

That said, flash heads are OEM products. So there's more of a coincidence than you think if the guide numbers are the same, or the F58 happens to have the same flash head as the 580EX II...

sidewinderz: Ken Rockwell's site says the SB-600 does 100 feet (30.48 meters) at 85mm. Which makes it even weaker than what Nikon's main site says, which is 98 feet/30 meters at 35mm!

http://imaging.nikon.com/products/imaging/...b-600/index.htm

braindead_fr3ak: A reason why I like the F42 and F58 is, they make very good battery testers.

Set flash power to 1/1. Press TEST button. Exactly 4 seconds later, the TEST button should light up again. If your batteries are not so fresh, they can take 5 to 6 seconds... and if it takes 7 seconds I know it's time to charge them.

The F56 cannot be used in this manner as it takes a lot longer for a full recharge.

I hope you all take precautions to big numbers - they could cheat you without knowing it by using feet instead of meters, or stating GN in ISO200 instead of ISO100 (and you can cheat them back by using GN at 105mm instead of 35mm which is weaker...)

hazril: The Metz does 54 meters at 105mm ISO100. Which is weaker than the Sony HVL-F58AM and Canon 580EX II!

This post has been edited by albnok: Nov 11 2009, 11:44 PM

hazril: Higher mAh will hold more charge.

Sigma 10-20mm F4-5.6 EX DC for A-mount has no HSM.

Sigma 10-20mm F3.5 EX DC HSM for A-mount has HSM.

Should be in the RM2k range.

http://www.dyxum.com/reviews/lenses/reviews.asp?IDLens=539

clivengu: Gah, my friends were stopped from taking pictures in Library. Pity, it's such a photogenic place!

v1rtual: The Tamron 90mm F2.8 Macro is popular because it is a cheaper insect macro lens.

On full-frame it is very close to the classic portrait focal length of 85mm. 100mm is a fair bit longer. Also, 100mm on APS-C as a walkaround seems a bit in-between.

achew: I like the stormtrooper's expression! Nice humor!

clivengu: 5pm +800 GMT.

http://www.timeanddate.com/worldclock/conv...0&p1=256&p2=122

hokc77: Nice play of strobe lights!

clivengu: I guess you could always try. Perhaps in the daytime they are less strict?

hazril: Books are too skema. How about laser backgrounds?

http://www.laserportraits.net/

This post has been edited by albnok: Nov 17 2009, 10:03 AM

v1rtual:

(Malaysian Time) = (+800 GMT)

So (5pm) (+800 GMT) = (5pm) (Malaysian Time)

I take it that Geografi was too many years ago for you.

clivengu: The beercan is already sharp at F4, but even better at F5.6. Unless you're using too slow a shutter speed (1/200s would be a good safe speed to have.)

I found the 70-300mm G to be equally sharp.

lildaredevil906: I was outdoors for a bit at 5:15pm and didn't see anything other than lots of clouds. They seem to say that it happens twice (5pm 17 Nov +800 GMT and 5am 18 Nov +800 GMT).

This is my remix!

marauderz: Sony.com.my is not reliable and is often outdated. So ignore that; besides you'd want to head to a shop to get it at street price.

achew: Dunno if you noticed, but I've made the circles have spherical illumination like how the STF does.

Will attempt to refine this on other pictures!

Your "after" shot still has bright edges on the circles (looks like just a Gaussian Blur.)

MemorableStudios: I am liking that smell!

This post has been edited by albnok: Nov 18 2009, 12:55 PM

LOL! The picture is of the HVL-F42AM!

People, don't bother referring to sony.com.my. It is not reliable at all:



I took a look at the latest Sony Time magazine (white color) and while it has the new Alpha models in the catalogue (A900, A850, A550, A330, A230) it does not have any of the 4 SAM lenses!



This post has been edited by albnok: Nov 18 2009, 02:36 PM

wuszhtag: I am certainly not the first to touch or buy an A900. I didn't buy it from Lowyat though.

However I was the first to get the HVL-F58AM and HVL-F20AM in Malaysia.

v1rtual: I would rather get a F58 + F42 for studio use. The quick swivel is of not much use on a light stand. The strobe function doesn't work wirelessly. The F42 is also smaller and lighter, so it makes a good backup for shooting events.

However, if I wanted 3, I would get a F58 + F58 + F42. The A700/A850/A900 can use one F58 on camera to control three groups:

CTRL (on-camera)
RMT (off-camera group 1)
RMT2 (off-camera group 2)

The F42 has no custom function to select whether it is in RMT or RMT2 so it is always in RMT.

The F58 has the option so it can be in RMT or RMT2.

Obviously, in order to have 2 off-camera groups, one of them needs to be in RMT2, and it can only be a F58.

So:

A700/A850/A900 + F58 in CTRL+ mode, power set by the CTRL ratio
F42 in WL mode, power set by the RMT ratio
F58 in WL mode in RMT2 group, power set by the RMT2 ratio

The only time I can imagine having two F58s (or a F58 and F56) is for event work, where I use the Sony FA-EB1AM battery pack and need to flash repeatedly quickly. It takes 6 AAs and plugs into the F56 or F58, to enable faster recharge times. I would say a 1/1 blast goes from 3.5-4 seconds (without battery pack) to 3-3.5 seconds (with battery pack). Of course, if you point direct you surely will not use a 1/1 blast.

Kul | Mo0: If you can ever come down to Laundry on a Thursday, I could get one of my friends with the Sigma 30mm F1.4 to come over and you can see what it's for.

achew: Congratulations on getting the effect you wanted!

Soony: Oh, but the Sigma 30mm F1.4 has superb contrast and color wide open! It even looks great on FF despite the vignetting.

lwliam: Happy birthday! And get yourself a Tamron 10-24mm F3.5-4.5 if you need the range and aperture. The argument of "I'm using one you should too" could come from a Canon/Nikon buddy.

Tamron 10-24mm F3.5-4.5 DiII versus Sigma 10-20mm F4-5.6 DC versus Konica Minolta 11-18mm F4.5-5.6 DT

signither: Silver trim is old batch.

lwliam: About all ultra-wide angle lenses have 77mm or 82mm filter threads.

freddy manson: Your computer screen is very likely not calibrated. Most LCDs for example are too blue-ish out of the factory.

achew: Lowest, weakest setting:

1/32 16mm (using wide-angle diffuser) at bounce up mode.

The difference between having wireless ratio control and cheap radio controllers with 2 flashes is that with the radio triggers you need to walk to the flash to change the flash power.

With wireless ratio control you can set:

-:4:1

This means CTRL = no flash, RMT = 4, RMT2 = 1. This uses TTL!

Where RMT flash (F42, or any F58 in RMT group) will be 4 times more powerful than RMT2 flashes.

An infinite number of flashes can be put in the RMT or RMT2 group. So you just need to figure out who goes where.

Uzumaki NaruTo: That is a complaint about the A3x0 series - that it does not gain up in Live View, for composition and macro purposes. The A500/A550 fixes that, in MF Check LV, as gain-up is applied.

achew: If you had the F20, you can use the F20 in TTL as a compact pop-up flash that also bounces. I'd suggest you get that so you get 2 true flashes instead of one flash which you always have to bring whether you need a big flash or not.

This post has been edited by albnok: Nov 20 2009, 03:59 PM

Apparently, CCFLs need high voltage (or an inverter):
http://www.fonerbooks.com/laptop14.htm

Left school too long ago to remember how to transform voltage up! Our batteries are 1.5 volts mostly. I would guess that 8 AAs would be needed for a 12 volt light?

This post has been edited by albnok: Nov 20 2009, 04:50 PM

Radio triggers are commonly used in;

1) bright sunlight where the pop-up flash signal may not reach the wireless flash (shading the wireless flash sensor works)
2) extreme long range

Given that you just want to prevent light spill, it is much easier to:

1) buy a roll of ASA100 12-frame film (RM5)
2) pull that roll of film out and expose it to light for a few seconds
3) send it to the same shop to process (RM5)

Now you have infrared-pass film! This blocks normal light but allows the flash signal from the IR spectrum to reach your off-camera F58. I would suggest taping the film over the F20 head (but make sure WL mode is on, or it will burn the film in TTL mode.)

You can also use the remainder film to cover your lens and work as a rudimentary IR pass filter.