UWA and Flash AF540


#1
I have difficulty getting coverage when shooting at 10mm with my Sigma 10-20mm with the Pentax flash AF540. I used the inbuilt diffuser; but still the side is not covered. I used bounced flash and still not great. Any suggestion on how to play around with the flash to cover its wide angle? I was taking some Chinese ink paintings for this famous Chinese Professor/artists, and got some of these issues. Some of his paintings are like 10~15 feet long; so I needed the UWA to cover it. I don't have studio lighting condition. Suggestions welcome, if I had to do it again!
 

tabako

Senior Member
Nov 25, 2005
1,104
1
38
#2
How about this diffuser, I have it. Place the diffuser 45 degree inward, and the bouce card backward or forward according to how much power you need. The diffuser wraps around the flash more than 180 degrees, so you can a all around diffused light.

http://photo-tips-online.com/review/demb-flash-diffuser/

Else you can buy a stofen flash diffuser, but you cannot adjust the softness of the light, or should I say hard to adjust unless you adjust flash power.
 

Last edited:

gymak90

New Member
Jan 5, 2008
1,448
1
0
The Far North
#3
Maybe you can change to another flash unit? I didn't have such problems using a nikon flash + 10-20.

You can also try getting a diffuser to "spread" the light to a wider angle.
 

#4
How about this diffuser, I have it. Place the diffuser 45 degree inward, and the bouce card backward or forward according to how much power you need. The diffuser wraps around the flash more than 180 degrees, so you can a all around diffused light.

http://photo-tips-online.com/review/demb-flash-diffuser/

Else you can buy a stofen flash diffuser, but you cannot adjust the softness of the light, or should I say hard to adjust unless you adjust flash power.
Where can I buy this diffuser in Singapore? Looks a good contraption. It seems to diffuse light much broader and better control of the bounce as well, as compared to a Stofen.
 

pinholecam

Moderator
Staff member
Jul 23, 2007
10,933
85
48
#6
Is it thru glass?
If not, you already have an easy deal. :)
I'm surprised they allowed flash photography in the first place.

Do you have a sample photo?

Why can't you just stand further from the painting when using direct flash?
(allowing the flash to spread a bit more to cover the whole painting)

I'm particularly interested in the one using bounced flash. It should create a lighted surface that is large enough to cover the painting. If it isn't, then likely you have not given enough distance between flash and bounce surface for the light from the flash to spread out over a larger bounce area.

There are a few ways as well.
1. Just use a tripod (using ambient light)

2. This one is more novel and needs trial and error to get overall exposure and light control right. Use a tripod; Set exposure to a very long one (Eg. 8s, f16). Take the flash off camera, set it to the exposure you want. Fire off the flash in different locations of painting (Eg. left, right)


Direct flash even with an on flash diffuser would likely cause a hotspot if the painting is covered with glass. You'd need a diffuser that is as large as the painting or a bounce what is a large surface area (as mentioned above).
 

#10
I have difficulty getting coverage when shooting at 10mm with my Sigma 10-20mm with the Pentax flash AF540. I used the inbuilt diffuser; but still the side is not covered. I used bounced flash and still not great. Any suggestion on how to play around with the flash to cover its wide angle? I was taking some Chinese ink paintings for this famous Chinese Professor/artists, and got some of these issues. Some of his paintings are like 10~15 feet long; so I needed the UWA to cover it. I don't have studio lighting condition. Suggestions welcome, if I had to do it again!


 

woonsin

New Member
Nov 10, 2007
566
0
0
Hougang
#11
it would be more nice to shoot photo with tripod instead of flash and your photos will be surely beautiful.
 

pinholecam

Moderator
Staff member
Jul 23, 2007
10,933
85
48
#13
It was shot on a tripod with the flash on bounce; no direct. The UWA is hard to cover, and I tried at 13mm onward; and not 10mm
If you used the tripod, exposing using ambient light should likely be better.

It all depends on what you think is good enough. To me the samples you posted are good enough if you just want a record (not a picture perfect copy that you can send to the printers :bsmilie: )

Light fall off from the flash would be very directional as in your sample photos. (ie. brighter on top, darker at the bottom). You'd need to bounce off a wall that is behind you to get an even lighting distribution in your case (I doubt you'd have that ;) ).


The 'option 2' I mentioned could be used as well, but I think just using the ambient would be far easier.
 

ricsal

New Member
Jun 23, 2007
1,549
0
0
#14
I thought the 540fg has an intergrated diffuser thigy on the flash? when u pulled it out, the flash will auto wide angel zoom. I know when pulled that thing out, there will have a zooming sound inside.
 

#15
I thought the 540fg has an intergrated diffuser thigy on the flash? when u pulled it out, the flash will auto wide angel zoom. I know when pulled that thing out, there will have a zooming sound inside.
Yes, I pulled that diffuser out as well to try...It has a diffuser and a white bounce card as well. Anyway it was fun doing it for the Professor. He just gave me one of his paintings as a "thank you" and a caligraphy with my name all in Chinese of course! I can't read it! But it was a good experience. The other thing I need is the spirit level, which is important to ensure horizontal positions. Need to buy one from the MASS SALES or just use my carpenter stuff with the bubble level.

Pinhole - he is using the photos which will need some pp to publish a book on his art pieces. So, will see how it goes.
 

pinholecam

Moderator
Staff member
Jul 23, 2007
10,933
85
48
#16
Yes, I pulled that diffuser out as well to try...It has a diffuser and a white bounce card as well. Anyway it was fun doing it for the Professor. He just gave me one of his paintings as a "thank you" and a caligraphy with my name all in Chinese of course! I can't read it! But it was a good experience. The other thing I need is the spirit level, which is important to ensure horizontal positions. Need to buy one from the MASS SALES or just use my carpenter stuff with the bubble level.

Pinhole - he is using the photos which will need some pp to publish a book on his art pieces. So, will see how it goes.
ah... you have approval from the owner.... :think:
Maybe you could have placed it on the floor (with newspaper as protection) or a table, then bounce off the flash to the ceiling. This would give you that large bounce surface.
 

ishou80

New Member
Mar 9, 2008
962
0
0
Choa Chu Kang
#18
If you are helping the owner to keep record, a tripod with longer exposure will work with perfect exposure and can cosider a stitching a few pic up as @ 10mm I think the distoration is quite visible?
 

#19
tripod and ambient light can work provided the ambient is providing even lighting to the paintings, else u will still see differences...

whatever light source, there will be fall off at the sides... even u use a very big softbox/umbrella also cannot cover this much area, u want even lighting, use 2 flash at both sides maybe can, else use a parabolic reflector... what u have cannot be achieve...
 

pinholecam

Moderator
Staff member
Jul 23, 2007
10,933
85
48
#20
Ok. Here are 2 test shots I did just to make sure I was not talking rubbish :D.
As mentioned by some, I'd have to say that a UWA is certainly not the most ideal lens for copy work. The distortions would be too much.

The headboard used is pretty long, about 15ft

#1 is done with a flash bounced off the fall behind me.

#2 is done with a long exposure and the flash fired off 2 times during that time. 1st time on the left 1/3 of the headboard and the 2nd on the right 1/3.

Flash was a low powered AF200T, so I had to raise the ISO a little as well.

#1 Flash bounced off wall behind.



#2 Long Exposure with 2 flash exposures triggered manually

 

Last edited:
Top Bottom