Sigma 8mm f3.5 or f4 ?
Hi Guys,
I'm new here and I had a lot of problems with stitching spherical panoramas precisely.
I currently use Fujifilm Finepix 6900 zoom camera with Opteka .22x HD² Fisheye Lens, Panosaurus Rotator from http://gregwired.com/pano/Pano.htm, Manfrotto 3001D Tripod 190CL + Panoweaver.
I think I need to change my current Camera & Lens...and maybe the panohead too (?)
Should I buy Sigma 8mm F3.5 or F4 ???
I think of using it with Nikon D50 (or maybe D70, D80, D100, D200 ???)
I have limited funds and the equipment isn't cheap...
I need your professional advice.
I'd appreciate any help.
Thanks,
Evelyn
Re: Sigma 8mm f3.5 or f4 ?
Evelyn
They have several Sigma 8mm f4 lenes on eBay and a couple f3.5s on Amazon.com for from $500 to a little over $600.
I've bought 2 refurbished Nikon cameras from Cameta Autions on eBay and have been very happy with the service. They're an authorized Nikon outlet. You might look there for your D50
I you're looking at a new rotator/panhead you might consider the Nodal Ninja. It pretty afforadble and has a good reputation. Its what I'm planning on when I move up from the Nikon Coolpix 8700 I just bought later this year or next year
Douglas Aurand
Albuquerque, NM
Re: Sigma 8mm f3.5 or f4 ?
I think the Sigma 8mmf3.5 is also a lot sharper than the f4 version. Some users have said it comes close to the Nikkor 10.5mm for sharpness but has more flair. I have had a Sigma 8mmf4 for about 3 years and it's not too bad, it just needs a fair amount of shapening and contrast enhancement. Also the definition falls off as you go twords infinity. I always shoot at at least f8 since anything below that just looks fuzzy and anything above f11 goes softer due to defraction. The lens has a limited range in which it looks good but you need to test to find it and then shoot in that range always. I am interested in replaceing the f4 but it may be a bit. If you just want to shoot and experiment for yourself then the f4 is good and if you can find a good deal on it then all the better.
Cheers
Robert C. Fisher
QTVR Photography/Cinematography
Re: Sigma 8mm f3.5 or f4 ?
Evelyn
Would you find it valuable if there was a Camera/Lens/Rotator Library on this site where members could evaluate the particular camera/lens/rotator combination they use.
And there would be actual photos taken with their combo you could download and test stitch to see what the results look like.
I outlined the idea in a Forum post http://beta.ivrpa.org/node/872 but have received no feedback. I got the idea from a page on the iPIX website where you can see sample source images and download them. Take a look http://www.ipix.com/products_iis_samples.html
Would you like to be the first to say what you think about the idea?
Douglas Aurand
Albuquerque, NM
Re: Sigma 8mm f3.5 or f4 ?
I am confused now after reading this thread. We are finally about to pull the trigger on our first get up for VR. My understanding was that the Sigma 8mm f4 was a better lens than the sigma 8mm f3..5.... I am using a canon 20d and a canon rebel 350d. We will have a 5d soon, too. Am I wrong to think we need the sigma 8mm f4?? any help is greatly appreciated.
Re: Sigma 8mm f3.5 or f4 ?
The Sigma f3.5 is reported to be brighter than the f4.0.
The specs for both lenses are on Sigma's website http://www.sigmaphoto.com/lenses/lenses_all.asp
Douglas Aurand
Albuquerque, NM
Re: Sigma 8mm f3.5 or f4 ?
pecheney
f3.5 is brighter as it allows more light through, f4.0 is therefor darker, requiring longer shutter speeds to compensate.
If it was f0, it would completely clear, as if no lens, so the closer to zero, the more expensive they are.
Most people prefer to have the option of a bright lens, in case you are in a situation of movement, as the brighter it is, the faster the shutter speed that can be used, so the less blur from movement.
Sorry for teaching my granny to suck eggs if you knew that already ;)
Ian
Re: Sigma 8mm f3.5 or f4 ?
A small addition / something you have to realise. At F8, both lenses are as bright as the other. That's - sort of - what F8 means; a certain amount of brightness. With the F3.5, you have the option to go half a stop brighter than with the F4. However, the F4 (and likely the F3.5, but I did not test when I got the chance... DOH!) is too soft to be really usable at F4.
Re: Sigma 8mm f3.5 or f4 ?
If it was f0, it would completely clear, as if no lens, so the closer to zero, the more expensive they are.
Not really - a lens with an aperture of f0 would be infinitely wide... ;-P
The aperture value is the distance from aperture/diaphragm to film/sensor, divided by the diameter of the aperture.
Ian
Re: Sigma 8mm f3.5 or f4 ?
The aperture would be infinitely wide, so it would not block any light. So in effect, it is fully transparent ('clear').
Ofcourse this means a f0 lens can not exist.
Re: Sigma 8mm f3.5 or f4 ?
The truth is either lens will probably serve you well.
The Sigma 8mm f4 has been a mainstay of the virtual imaging industry for several years.
All of the cameras you mention have a lot of resolution to work with so your results will depend on your experience & skill with the camera/lens/rotator as much as the equipment itself.
Just expect to do a lot of experimenting and trial & error like we all do with our respective setups & software.
Douglas Aurand
Albuquerque, NM
Re: Sigma 8mm f3.5 or f4 ?
I moved your post to the public forum, and removed the one on the members only forum; in the public forum you will probably get more response, as it is read by more people.
The Sigma f3.5 is newer than the f4. It has a slightly larger image circle (so there will probably be a bit of crop from the left/right as well as the normal larger crop from the top/bottom (in landscape). It has less vignetting and also slightly less CA in my limited testing.
It might be easier to find a good deal on a f4 lens, because the f3.5 seems to be still in limited supply.