Software bug of D70?

[cheersjy]

When i was trying to take some photos on my wife using A mode (ISO auto) with wide aperture that day, everything was fine initially.

http://www.pbase.com/cheersjy18/image/43160147

Feeling that some filled flash may help brighten up her face under the direct sunlight, i activated the flash. The LCD gave a "HI" warning, indicating that the photo will be overexposed. I did not heed it, thinking that the tiny flash is neglegible compare to the bright sun. Well, this is the resultant photo:

http://www.pbase.com/cheersjy18/image/43160149

I cannot understand why the vase difference between the 2 photos. Just because of the tiny built in flash used? It cannot possibly lit up all the flowers that were more than hundred metres away.

After playing around with the setting, i found that if i want to use flash under sunlight, i need to stop down to f/9 - f/11. The exposure is correct now, but i lose the bokeh

http://www.pbase.com/cheersjy18/image/43160151

Is this a software bug of D70? Or something wrong with my setting? Is there any way to take use flash when aperture is wide open? I did not notice the problem when i used my digicam before, can activate the flash whenever i like.

Your advice and sharing is much appreciated. Thank you!!

[espn]

This occurs when the exposure for the setting you were using is not ideal for flash photography.

ie: f/2.8 at 1/2500s for the 1st image.

The sync speed already exceeded beyond what the D70 can handle - 1/500s. Thus if you force the camera to use flash, it will need to step down the shutter to sync at 1/500s, which is approx 3 stops; and more light allowed to go in at f/2.8.

Thus the same image @ f/2.8 1/500s = overexposed (with flash somemore).

f/2.8 -> f/8 ~= 3 stops difference, it compensates for the flash sync speed.

It's not a bug, rather on how you use the kamela

[espn]

Another reason why your digicam didn't give you the same problem is simple.

There's also crop factor on the DCs.

Take my CoolPix 5700 for example 8.9-71.2mm (~35-280mm).

The aperture is f/2.8-8, but if we take the crop factor into consideration -

35 / 8.9 = 3.9

at f/2.8 *= 3.9 = f/11 on SLR measures. Thus you don't see this problem on DCs.

[mohgui]

what about trying to meter some dark areas? will it help?

[cheersjy]

Originally Posted by espn The sync speed already exceeded beyond what the D70 can handle - 1/500s. Thus if you force the camera to use flash, it will need to step down the shutter to sync at 1/500s, which is approx 3 stops; and more light allowed to go in at f/2.8.

Wow espn, u are always the first to provide help!! A big thank you!!

Sorry for my poor understanding on the use of DSLR - do you mean that when flash is activated, the fastest shuttle speed it can go is 1/500? Why this problem does not occur on digicam (at f/2.0 some more)?

And back to my most concerned question - since we cannot use flash under strong light + wide aperture (i never realize this before), is there any way to create good bokeh with the subject's face well lit? Reflector the only way?

[cheersjy]

Originally Posted by cheersjy Wow espn, u are always the first to provide help!! A big thank you!! Sorry for my poor understanding on the use of DSLR - do you mean that when flash is activated, the fastest shuttle speed it can go is 1/500? Why this problem does not occur on digicam (at f/2.0 some more)? And back to my most concerned question - since we cannot use flash under strong light + wide aperture (i never realize this before), is there any way to create good bokeh with the subject's face well lit? Reflector the only way?

Oops, espn u are fast! Forget the digicam question

[espn]

The shutter speed syncs with the flash and that's the fastest it can go on the D70, D100's only 1/180s so don't complain ok!

Regarding your DC question, refer to my 2nd reply, 3rd post in this thread.

You can use flash under strong light, but I'm still figuring out how (camera + flash on hotshoe), one way is to step up the aperture, the other is to use slave flash and trigger it like a softbox for fill in.

When I got chance to play and find out more I'll share my findings, or perhaps those more adept at using flash for fill in can answer you.

The other way is reflector as you mentioned, which of course, works best if you have your own PA

[espn]

Oh yeah, now I remember why I use off hot-shoe flash instead of mounting the flash on the kamela.

When you meter, the body calculates the area you meter and exposes the frame with the flash intended at the area you meter.

When I use the flash off the body, the flash only acts like fill in (since I adjust the flash output power manually, I can control the harshness of it).

Hope it helps... I no flash expert user myself.

[mpenza]

It's a limitation of the D70.

When using flash (on i-ttl mode) or the built-in flash, you can only go as fast as 1/500s for shutter speed. So, if you want to use flash with a fast lens wide open under bright sunlight (assuming the lowest ISO still result in a shutter speed faster than 1/500s - the x-sync speed), you'll need to use neutral density (ND) filters to reduce the shutter speed, else you need to stop down to prevent overexposure.

Take a look at the last part of the following article for an illustration:
http://www.cs.mtu.edu/~shene/DigiCam...filter-ND.html

On bodies like the Nikon D2H and D2X (and all Canon DSLRs for the matter), the availability of high speed flash sync mode allows you to use shutter speeds faster than the x-sync speed of the cameras (1/250s for the D2H) with (external) flash. Down-side to the high speed sync mode is the reduced flash range. It usually doesn't matter so much if you're using flash as a fill-in.

[espn]

For a moment, I thought mpenza was going to do what I do best

[cheersjy]

Originally Posted by espn The shutter speed syncs with the flash and that's the fastest it can go on the D70, D100's only 1/180s so don't complain ok!

Now i remember i read somewhere about the benefit of 1/500 syncs on D70. Now only i understand.

Originally Posted by espn When I use the flash off the body, the flash only acts like fill in (since I adjust the flash output power manually, I can control the harshness of it).

In this case, how to syn both the flash and the D70 at, for example, 1/2500? Well, you don't have to reply as i guess i need more practice and knowledge to get this right

[espn]

Originally Posted by cheersjy In this case, how to syn both the flash and the D70 at, for example, 1/2500? Well, you don't have to reply as i guess i need more practice and knowledge to get this right

For me personally, I use a IR trigger, it triggers the flash the same time I trigger the camera

It's not really sync, but rather just triggering the flash for output.

[mpenza]

Originally Posted by cheersjy Now i remember i read somewhere about the benefit of 1/500 syncs on D70. Now only i understand. In this case, how to syn both the flash and the D70 at, for example, 1/2500? Well, you don't have to reply as i guess i need more practice and knowledge to get this right

Highspeed flash sync mode allows D2H and D2X to sync as fast as 1/8000s. This is not available for the D70 though, so the fastest is 1/500s. There're ways to "cheat" by using auto or manual flash modes instead of i-TTL mode.

[cheersjy]

I see. Thanks to both masters for the kind patience in explanation. Really grateful.

Allow me to OT a bit to ask another question - i am now taking the photos in Adobe RGB space and the colours look different in photoshop and Internet Explorer. When i send for develop after adjustments made in PS, do i need to switch the colour mode back to sRGB again? or i can send in Adobe RGB mode? BTW, i usually sent to Fuji shop (Grace).

[gooseberry]

Originally Posted by cheersjy I see. Thanks to both masters for the kind patience in explanation. Really grateful. Allow me to OT a bit to ask another question - i am now taking the photos in Adobe RGB space and the colours look different in photoshop and Internet Explorer. When i send for develop after adjustments made in PS, do i need to switch the colour mode back to sRGB again? or i can send in Adobe RGB mode? BTW, i usually sent to Fuji shop (Grace).

Looks different in IE because IE doesn't understand AdobeRGB. Best to convert it to sRGB before sending for printing.

[espn]

Originally Posted by cheersjy I see. Thanks to both masters for the kind patience in explanation. Really grateful. Allow me to OT a bit to ask another question - i am now taking the photos in Adobe RGB space and the colours look different in photoshop and Internet Explorer. When i send for develop after adjustments made in PS, do i need to switch the colour mode back to sRGB again? or i can send in Adobe RGB mode? BTW, i usually sent to Fuji shop (Grace).

Adobe RGB's colour space exceeds that of the sRGB, thus the colours & contrast will look much better, but when printing, the colour space is only sRGB on most lab printers as it's almost near impossible to reproduce the vast colour space of ARGB.

As gooseberry replied, it's best to convert into sRGB and send it in. Normally you can use Mode I sRGB for humans, and Mode III sRGB for landscapes, I've never used Mode II before myself so can't comment much.

Now, where's that Watcher when you need him to explain ARGB?

[Watcher]

Originally Posted by espn Adobe RGB's colour space exceeds that of the sRGB, thus the colours & contrast will look much better, but when printing, the colour space is only sRGB on most lab printers as it's almost near impossible to reproduce the vast colour space of ARGB. As gooseberry replied, it's best to convert into sRGB and send it in. Normally you can use Mode I sRGB for humans, and Mode III sRGB for landscapes, I've never used Mode II before myself so can't comment much. Now, where's that Watcher when you need him to explain ARGB?

Ha ha, unlike you, I don't do the "I'm in/I'm Out" thingy

ARGB? Short story: established by Adobe, primarily for print as it covers more of the CMYK 4-color separation print space, compared to sRGB. Used on DSLR to capture more more saturated tones and more subtle tones if used with RAW.

Long story: Buy me a pot of tea; it can take up to 1 hour to explain all the ins, outs and implications and colorspaces

[cheersjy]

Haha, thanks for all the kind explanations. i think i got the answer i need liao - take photo with ARGB, but convert to SRGB before sending for printing

[reflecx]

Originally Posted by espn Another reason why your digicam didn't give you the same problem is simple. There's also crop factor on the DCs. Take my CoolPix 5700 for example 8.9-71.2mm (~35-280mm). The aperture is f/2.8-8, but if we take the crop factor into consideration - 35 / 8.9 = 3.9 at f/2.8 *= 3.9 = f/11 on SLR measures. Thus you don't see this problem on DCs.

No lah, f2.8 on digicam is same as f2.8 on DSLR. You're probably talking about the equivalent depth of field here.

The reason is that digicams do not have a shutter and thus are able to sync at almost any shutter speed.

[mpenza]

yup, the in terms of exposure, f2.8 on a digicam is the same as f2.8 on a DSLR. crop factor doesn't come into play for exposure.