Update to Kodak DX6490 exposure problem

Archived from groups: rec.photo.digital (More info?)

On Dec 26/04, I posted a question about a problem I was having with my Kodak
DX6490 and underexposed pictures. The underexposures occurred when using the
on-camera flash and the lens adapter that Kodak manufactures for the DX6490
and DX7590. I had suspected that the rim of the adapter was blocking the
flash and creating a condition that would cause the underexposure. Since
that time I have been corresponding with Kodak's technical people as well as
a contributor to this newsgroup, Ron Baird. I have attached Ron's reply
that explains why this problem exists. Although there is no way to correct
this problem Ron has assured me that Kodak will be looking at possible
design changes to the adapter or future versions of the camera. Hopefully
I'm not in violation of any newsgroup rules by saying that I was more than
pleased with the way Kodak handled my concerns.

-----Original Message-----

> From: Ronald Baird [mailto:ronbaird@kodak.com]

> Sent: Monday, January 10, 2005 1:02 PM

> To: Roots750@******

> Subject: RE: News Group Rec.Photo.digital Re: Kodak DX6490 Lens

> adapter and

> exposure problems

>

> Greetings ,

Thanks for the update on your concern.

> I have been sharing with Jeremy, the fellow who responded to you and

> who has

> worked over the weekend on this issue along with other engineers, to

> find out why this condition is happening. He found that the flash was

> NOT being

> blocked. Rather, the camera is adjusting exposure when the flash is

> reflected back into the exposure meter by the lip of the adapter.

> This is resulting in a slightly reduced exposure.

>

> He tested the camera in several ways, and this does seem to be case.

> The adapter does has an effect on exposures taken with the built-in

> flash.

> Every test picture he took with the adapter on has been slightly under

> exposed. The key is that it is an even underexposure. The proof,

> however, is in the pictures which shows that the flash is indeed not

> being blocked, save for an

> extreme close-up. Rather, when you find underexposure resulting from

> this it

> is even, with the lower portion of the image as underexposed as the

> upper portion. This would not be the case if the flash were blocked in

> a meaningful way.

>

> It was also found that the adapter, when used in extreme close-ups

> with built in flash, may leave an arc at the bottom of the image.

> Since there is

> no intended use of the camera in this way (no accessories are offered)

> the condition noted should not make a difference. This phenomenon will

> not occur

> if you are using an external flash or ambient light alone.

>

> Actually, the adapter was designed to hold accessory lenses, i.e. a

> wide-angle, a polarizing, or a neutral density filter; it was never

intended

> to be a lens protector. It does work quite well in this role, but that

> was not its intended use. Your best bet in overcoming this situation

> is to use the external flash option. It gives you the most control

> over your flash photography and is one of the great features of this

> camera.

>

> Hope this helps you understand, if you have any other questions

> in this regard, let me know.

>

> Ron Baird

> Eastman Kodak Company