I picked up a secondhand but very mint condition Sigma 300mm f2.8 EX HSM Lens today. Although hardly cheap, the price was extremely good compared to the new price so couldn't resist .
Initial tests show that starfields are very sharp across the whole field of my 350D at f4.0 (with pretty good results at f3.5). I am guessing the lens would be quite usable wide open for daylight photography.
Attached is a photo show the 350D connected to the 300 2.8, and for comparision the 200 f2.8 L and the standard 18-55 kit lens are shown next to it (so you can see this is not a small lens!). Anyway once I hope to do a more thorough report soon.
About 4K Aus (and I think I have seen it as low as $3700). I payed $1800 which I reckon is very reasonable for that lens given its excellent condition. I am a bit dubious about buying second hand lenses but this was local so I could verify it was in mint condition. You have to watch for fungus and similiar damage in lenses especially in a humid climate (I've been caught before!).
I would have liked to have picked up one of the older Canon 300 2.8 non-IS but haven't seen one of those for a while. I suspect the Canon will be better wide open a f2.8 but expect to pay 3K + for one in OK condition.
Good buy Terry. A quick question about lenses though. When do you think you will run out of room at your place and have to start selling some of them off
Note this is the non-DG version (The DG apparently has better coatings that minimise flare/ghosting but are similiar if not the same optically).
Paul, yep starting to get too crowded. I am thinking of selling my 28 f2.8 and 50 f18 actually because I'm not using them (I use the Sigma 17-70 for those focal lengths, although the primes are sharper).
Terry the Sigma 300F2.8 EX HSM is a very good lens. I would try to get perfect focus at F2.8 as the depth of field is miniscule. I built a stepper focuser for my 300mm F2.8L and can see a difference in focus with 0.1mm linear movement in the focus ring at F2.8!
Here http://www.iceinspace.com.au/forum/s...ad.php?t=11859
The problem with IS versions of any lens is if the 'park position' of the IS assembly is not exactly on the optic axis you have a problem with what looks like astigmatism but is due to misalignment.
Part of the problem I think is with blue Halos, I am going to try the lens again with the modified camera as it has a sharper cutoff at the blue-end than does the standard Canon lens. You see the fainter stars are actually quite good.
I must not read this thread , must ignore the massive nice whopping f.2.8 lens must ignore, must ignore, must ignore....................oh be done with it, I need to move my Pentax gear before I entertain this idea.
I have updated my webpage (this time with test images from my modded 300D) and I am now pretty confident I have near optimal focus. Spoke to the Sigma tech at CR Kennedy and he mentioned that the DG series underwent a lot of enhancements (not just coatings) that improved lens performance when used with DSLR's. The lens was checked out as being within specification from a recent service when the previous owner complained about softness at f2.8 (incidentally he did not disclose and a few other minor issues during the purchase).
So the lesson here is get the DG designated version if possible, but if a non-DG lens is the choice then be prepared to down an extra 0.5 stop.
I was thinking of getting the DG version at some stage. I've already got the 120-300f2.8 so it might be overkill but primes are so sharp. I did just have to sell my 200f2.8 because the missus found out I bought it so I'd probably have to sell any 300f2.8 I bought too
I started out this week planning to get another 200mm lens. I have 2 Canon DLSRs that I use them to do sky surveys (for comets, nova, etc) and use the 100 and 200 lens. The 100 lens was starting to get too small for what I needed. I was even looking at that lens you offered
Then came the 300 2.8 and couldn't pass the offer up even if it is a non-DG.
I can tell you the Sigma 300 lenses are superbly sharp. Even my non-DG version is almost equally sharp at f2.8 as it is at f8, the problem being the flaring effect. In daylight shots this results in loss of contrast at f2.8 (making the image appear soft), so you need to stop to f3.5 to get punchy sharp images. I have corresponded with somebody with the DG version and he says it is as sharp at f2.8 as it is at f8 (and is superbly sharp at that). I think you can pick up one for under $4K in Aus but not sure if the Missus wouldn't find out and you'll have trouble hidding it! Also its a lot of lens to lug around why not go for the Canon 300 f4 IS?
I was thinking of getting the DG version at some stage. I've already got the 120-300f2.8 so it might be overkill but primes are so sharp. I did just have to sell my 200f2.8 because the missus found out I bought it so I'd probably have to sell any 300f2.8 I bought too
and thanks to your wife's eagle eye i am its proud owner. Now we have had more rain come down than for the entire month of october this wekend. have you some examplesd of the 120-300 f2.8 (I take it is a sigma lens?)
I don't think this lens is in the same League as the non-IS Flourite Canon 300 2.8 but does a pretty good job at f3.5 (see images). Even a f3.5 it is still not as good as the Takahashi Epsilon at the corners (although at the centre I think the Sigma might be a touch sharper). Interestingly, the lens seems to work slightly better with my modified 300D. I'll try to reshoot the LMC tonight with that camera for a comparision.
Terry nothing built with 'ordinary glass' even ED at F2.8 can come close to perfect lack of CA and astigmatism. Why they get away with it at short focal lengths is because you or the camera can't see it.
The lens I lent to Scott was the first of really well corrected telephoto lenses. In fact if you have seen the start of 'Tootsie' where Dustin Hoffman walks down the street in the general crowd taken from way back was taken with the lens Scott has got in his possesion (or one exactly like it) and it was wide open at F2.8 to differentiate him from the crowd.
I could not resist owning it even though I did not need it. It pleases me that Scott is making good use of it.
The Canon 300mm F2.8L I think is better than the IS version for astrophotography. You have seen the images it can produce.
At least for the price you paid you have a quite usable lens. Most telephotos have very noticeable purple fringes.
It certainly seems that way especially seeing your impressive images with the 5DH. I think the Sigma is a nice lens but my expectations were very high in part due to some of the excellent reviews I've seen.
The fast (2.8) Canon non-IS lenses don't seem to perform well as seen by these results by Jerry Lodriguss:
Jerry 'focused' by using auto focus. He did not try again and again to get it correct!
Smart guy but lack of real evaluation. I did not get very good results until I built a stepper focuser for the lens. Then I found out how good it really was.
Thats problably true. I think that jerry is also a perfectionist, notice his sample images are 500% enlarged. He also has used some of the finest APO refractors around and having seen full size raw files from these instruments the sharpness edge to edge is breathtaking (then again we are talking f7 here!).
Look at your images I don't think I have ever seen better images at f2.8 they show fantastic sharpness even at the edges. Wonderful stuff, especially with the fullframe.
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A quick question about lenses though. When do you think you will run out of room at your place and have to start selling some of them off 
, must ignore 
