wisp

Hi all,

I thought I had seen something related to this at one point, but was unable to

find it in a search. My tamron zoom is overexposing by 3-4 stops (and yes, it

is the lens - if I switch the lens, the camera meters fine) - could this be a

case of dirty contacts on the lens? If so, what is the best way to clean it? I

have some ?sp? kaig deoxit gold. It is an older lense given to me by my father.

Camera is a new D200.

Thanks in advance.

The only time I think you would really be concerned with the circle of confusion relative to your own gear (and images) is if you were actually doing DOF calculations on your body/lense combo - in that case, the circle of confusion is determining what is "well enough" focused, (or not too out-of-focus) to be considered within the DOF.

That's my (limited) understanding anyway - but Michael may also be right, at least for me as I don't really plan on using DOF calculators and memorizing their results for when I shoot - I sure as hell am not going to lug a computer around with me to consult before I take a shot.

I have personally had very good luck recovering images using 'photorec': http://www.cgsecurity.org/photorec.html - I ran it under linux, but it appears to be ported to windows as well. I have used it three times, twice with good results - the disks in all three cases did not even appear to be valid media to the operating system.

Good luck. Once you recover the images, you should be able to do some low level disk work to refresh the partition table and then reformat. I am still using (with no errors) disks that had previously 'failed' (although I will honestly say that I don't trust them very much)

Was it taken on a windy day? (I have not looked at your exif data, so I don't know how long of an exposure you used) It almost looks like the tree in the background is moving "up and down" (but that can be very dependent on perspective - might really be forward and back) - also might explain why another image had it but not to the same degree.

random guess.

I'm still not convinced that they are fakes - manufacturers will often change the specificatios of a device that is sold as the same model. Different world, but have you read about the Linksys WRT54G routers? There are seven different versions (last time I checked) of the basic WRT54G, most of which have vastly different hardware, firmware and capabilities (of running 3rd party firmware anyway), yet they are all sold as WRT54G Routers. You can tell by the serial number range what version you have.

This may be a different issue, but I would need to see a statement by SanDisk detailing how to tell a genuine SanDisk card before I got too worried about cards that were purchased via normal (non-auction) channels.

I checked my recently purchased (from Adorama via Amazon) 4GB Extreme III card and I am seeing a very similar pattern to the previous posters' (including how the serial number begins and the lack of a microswitch - I don't believe a 4GB card can even be formatted in FAT16, but I may be wrong about that) - I think this might be more applicable to cards bought on ebay and such, as I doubt B&H and Adorama are willing to risk their reputations by dealing with anyone except authorized distributors (clearly marked Gray Market items are an exception, but they are very forthcoming with that information).

I don't think I have a fake.

We recently bought our first DSLR - we ended up with a Nikon D200 for variuos reasons, but what steered us away from Canon initially was that the XTi didn't fit my hand (it fit my wife's hand great). As we were blinded by megapixels at that time (as I think many newbies are), we did not seriously consider the 20D/30D and wrote off Canon. I have since learned (somewhat to my chagrin) from a friend who has the XT that adding the extra battery pack to the XT (or XTi) gives it the height that makes it comfortable for a man with reasonably large hands to hold. I am very happy with the D200 and don't really have buyers remorse, but be aware that there is the option of increasing the height of the XT(i) if it isn't comfortable. Of course, it also adds additional cost and that would probably blow your budget.

DEFINITELY handle the camera model before you buy it.

Best of luck - I imagine that either will serve you well.

David (and others who have commented),

That was exactly my point in reference to out of focus being different at different focal lengths.

Thanks for the discussion.

Hi Greg,

Thank you - I have seen that DOF calculator before, but the circle of confusion they use seems to be a much tighter standard (defining what is in focus as opposed to how far something is out of focus) - in all three of the test images I linked to, the background was "out of focus", but they were out of focus to different degrees.

I know this subject gets beaten to death a bit but I didn't want to hijack

another post.

There was a post yesterday on canon macro lenses

(http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00JMa3&unified_p=1) that

discussed background blur a little bit, specifically a comment by carnagex

carnagex, who linked to an excellent set of example images

(http://www.photo.net/bboard/uploaded-file?bboard_upload_id=34244084) that shows

different background blurring for different focal length lenses at the same f-stop.

My understanding of f-stop is that it is the ratio of focal length to aperture

diameter (http://en.wikipedia.org/wiki/F-stop) (as wikipedia is my external

brain...), so it doesn't seem like the above image (which was shot with all

lenses at f16) is really a fair comparison. My rationale for this is that the

degree to something is out of focus is going to be related to how parallel the

light rays coming off of it are (think simple lense or pinhole) and therefore

the actual diameter of the opening is important, not the ratio of that diameter

to the focal length. In this case, the three focal lengths were 180mm, 100mm,

and 60mm @ f16

Equal aperture openings would be: 180@f28.8, 100@f16, and 60@f9.6 - rounded to

reasonable f-stops: 180@f32, 100@f16 and 60@f11

Has anyone done this type of test? I don't have 3 macros (only a 105) or even 3

primes or I would try it myself.

Thoughts/feedback appreciated.

You can make your own (that's what I am doing) - allows you to customize the connector, the length of the cable, the mount for the GPS (mine will be an old hotshoe bracket from an SB-10). I purchased an MC-23 from B&H for $65 (it gives me two ends - one will be a remote cable release for my dad) and as I have a Holux GPSlim236, will be using a USB mini-B for the GPS end.

Check out hackaday.com or just google - you do need to do a little soldering to add the serial converter though, so if that's not your bag it might be better to wait.

I'll post mine when I have it finished - I am hoping to complete it this weekend.

I would add one more criteria that was important to me, but admittedly this is only of interest to a minority of shooters: GPS (geocode) capability.

The D200 (and its big brothers) have it, the D80 doesn't.

That, with the AI/AIS lense bit was what convinced me to go with the D200 over the D80 (and then to convince my wife...)

HTH,

j.

I had read somewhere (where, I can't remember) that this was intentional on Nikon's part, but that they would make the clamp operational if you sent it in to be serviced.

Seems very weird, but you might try giving Nikon support a call.

HTH,

j.

I ran into this when taking some macro shots under windy conditions (you can see these shots in my gallery currently, although I may replace them at some point) - I had the flash-sync set to 1/250th and did not realize that the camera (in A mode) was chosing a lower shutter speed (1/60th is as fast as you can set it in the menu - which I find mildly annoying). The solution is to either shoot in S mode (shutter priority) and set the shutter speed to 1/250th (or whatever you want) or full manual mode - set the shutter and play with the aperture as necc.

HTH (although given how late my comment is, it probably won't be)

j.

You have two options (this is also covered in other threads, but I had trouble finding the info, so here it is again):

<br><br>1) buy a STD-1D module for your 444D and lose the TTL pin (which won't work anyway)<br><br>2) put a piece of gaffer's tape over the foward-most contact on the flash hot-shoe. This worked for me on my D200 and 444D, see <a href="http://blog.willowisp.net/?p=25">my blog post on this issue</a> with a DX-12R (I also own and have tested a 444D)<br><br>HTH,<br>j.