Hi there all,

I have been trying to convince my self otherwise till today, but I am getting a hotspot with my Nikkor 18-70mm f3.5-4.5G ED lens.

I thought that Nikkor lens's didn't have that problem; but it looks like they might.

Here is an example :-

(IMG:http://www.irphotography.org/gallery/albums/userpics/10008/Hotspot.jpg)

teerex,
I am becoming unhappy because I had many times today when the mirror locked about 2/3rd up
Giving be a black section at the bottom 1/3rd of the pics.

Ahhhhh, my new toy is broken ! hot spots and mirror sticky .... my shutter count is only 945 !

Tell me somthing to ease my pain my friend

Looks like I will have to send it in for service

Cheers

Pablo,

Sorry to hear about the mirror. I'm even more sorry because I'm going to be the bearer of bad news and tell you that the Nikkor 18-70mm is quite susceptible to hotspots, particularly if your aperture is stopped down when the lens is at its widest.

From the various tests that I've done, both with a regular D70 and a D70i, I can only conclude that hotspots are not caused by long exposures like what is claimed by writers on some websites. If you guys remember a small review I did on the Tokina 12-24 sometime back where I mentioned that it was prone to hotspots at the wide end, stopped down? Well, that problem still exists on my converted D70, albeit a little less. This hotspot issue was also seen, although only very slightly, on the Sigma 10-20.

What it's beginning to look like is that we are more likely to see hotspots in wide angled zooms when they are used at their wide end, stopped down. However, I can't tell whether this is lens specific or camera specific or combinations of both. I've seen photos taken with other cameras using other branded 10-20mms that don't seem to have the hotspot issues, but I must admit that they weren't exactly used at their widest end.

Test, test, test, test...gotta do more test, test, test, test...

Cheers,
Matt

From my experience, don't stop down to f8 and below. I normally shoot at f3.5 to 5.6. When using Peleng 8mm fisheye, I stopped down to f8.

I've tried stopping down to f16-22 once(Changi Outing), realised the most of my image have hotspots.

So, try the kit lens again, should be alright. Most of us, if not, all of us D70 users here used the kit lens to shoot.

Max is right, all of us use the kit lens to shoot and no hot spots.

One thing I always have in mind when shooting - never, never shoot at full wide. Most if not all my shots are done from 24mm onwards. Definitely no hot spot.

Get the camera in for a service since you're having the mirror lockup problem. Can have your CCD cleaned at the same time, the Ark will tell you that your shots are "clean".

Hi guys,

Your points are well noted and I will take care to follow them when shooting next.

I rather like the lens and was hoping to not buy another too soon, but I would appreciate any suggestions on a good replacement.

As it is. I was hoping to make do with the one lens for IR and concentrate on any additional money spent on lens's for the 20D.

But, I would not be happy using the D70 for IR if the lens I have is restricted by the hot spot problem.

So, as I said, "I would appreciate any suggestions on a good replacement".

Thanks again for your input.

Cheers guys

Ever thought about the Nikkor AFS DX 17-55mm f/2.8G IF-ED

This guy over at this forum here actually uses this lens for IR, complete with a 77mm B+W 093 and now he's going for a 77mm Hoya R72. Talk about money to burn.

Cheers,
Matt

Hi Pablo,
maybe you can try shooting using Aperture Piority and set to F8.
This is how I usually shoot. I still get hotspots in some of the photos...
But most of them are hotspot free

It has been said in some discussion for this that the hotspot is casued by light entering the view finder.

http://www.pbase.com/bclee123/ir_1st_attempt

Will try it this weekend.

Like to share.... Previously I got the hotspot too... now any of IR shot, I will cover the viewfinder. It will help in get rid of the hotspot and also better exposure.

Janson, why don't you join in the outing this Sunday?

Cheers!

I would love to, but sunday is a very lazy day for me... hahaha

Just to confirm, covering the view finder really does the trick?

17-55 is a very nice lens and can be a replacement for the 18-70 kit lens but must be careful if you are to get one. Heard that the production is not consistence.
You may want to keep the kit lens for occasion where you want to carry light or more casual shooting as it will not block the build in flash like the 17-55 do.

hello guys,

here is the reply i've got from sigma usa, stil does not give a proper answer for the hotspot.

Cheers!
Janson



Dear Janson



Thank you for your inquiry. The F2.8 lens may be more susceptible to glare caused by strong light sources, (e.g. Sun, etc.) striking or directly or entering the front of the lens, but we have heard no reports of excessive IR hot spots being experienced with either of these lenses. Remember that digital camera sensors are very sensitive to IR light, and most is filtered out with IR cut-off filters, etc. If you intend to do IR photography, we don’t know how effectively you can do this with your digital camera. But, Good Luck! And remember to use your lens hood and to remove any unnecessary filters form the lens.



Sincerely



SCA




--------------------------------------------------------------------------------

From: Sigma Customer Services [mailto:cchurana@sigmaphoto.com]
Sent: Tuesday, October 11, 2005 1:50 PM
To: tsobey@sigmaphoto.com
Subject: FW: IR avalibility








--------------------------------------------------------------------------------

From: Sim, Janson [mailto:Janson.Sim@BHPBilliton.com]
Sent: Monday, October 10, 2005 3:09 AM
To: info@sigmaphoto.com
Subject: IR avalibility



Hi There,



I am interested to purchase some of your lens namely the

Sigma 18 - 50 mm F2.8 or the cheeper 18 - 50 F3.5 or 18 - 200 F3.5 for my Canon 350D. However I've read in several forum that there might be IR hotspots in photos for some of the lens. It would be great if the team at sigma could confirm if there would be any hotspot problem with any of the lens listed above when used on a 350D and with a IR filter on?

Jason, you may be correct as I shoot with wide lens and sometimes with big apertures and still did not notice any hot spot. One thing is I always cover the viewfinder as it distort the exposure metering as well.

It can't exclusively be that, as I wrestle with it on my non-SLR digital.

--Chris