conurus

[AX-fan]

Quick question for those who have these two lenses... or even one of these beautiful lenses:

What do you think of the 70-200 (3.5-4.5) or the 70-300 (4-5.6) in their shared ranges re: sharpness, clarity and even their AF response?

[tk45]

I've been wondering the same. I've heard that the 70-200mm is sharper. But I also heard that the 70-200mm is designed by Sigma, and is the kit lens for DX. 70-300 is kit lens for N1.

[doctorb]

My 70-200 N seemed sharper than my 70-300 N especially zoomed to the long side. That is te reason that I sold my copy.

Now, for a different reason I am looking for a converted 70-300 to complete the collection, (When I sold it I didn't envision owning all nine, but I will shortly).

[conurus]

Unlike the other 8 lenses in the N line-up, the Vario-Sonnar 70-300/4-5.6 has very wide quality variations. A good copy can be really good but a bad copy can be pretty bad. If you contemplate buying one, make sure you test it on a Contax N camera body immediately for optical quality and return it for a refund if you get a lemon.

I have had at least 3 customers who are unhappy with their 70-300 lenses, which were just not sharp enough wide open. Now I know there are also many customers who are happy and got really good wide open performance, but I think I am somewhat obliged to point out that the 70-300 may turn out to be a risky investment and everyone needs to be very careful.

There are also a small percentage of samples autofocusing unreliably or very slowly. Some samples would get stuck in the middle of the focusing range, e.g. at 3m or 8m.

Typically, the ones with large serial numbers are great (e.g. 12686xxx or above) and those with small serial numbers are not (e.g. 12682xxx or below). However there is no hard and fast rule. It is possible for you to get a great lens with a low serial number but a lemon with a high serial number.

[edit 2010/08/02: I have to correct myself. Just tested a batch of lenses, with five 12682xxx coming out all good, but the bad ones are a 12683xxx, 12684xxx and 12686xxx. Lemons occur randomly and there are no correlation with serial numbers.]

We just converted every incoming 70-300 assuming they are good, but if it turns out to be a lemon, we are very happy to transfer the mount and the circuit board, free of charge, to a different 70-300 that you are responsible for procuring. However, there is nothing we can do to improve the optical quality of a lemon, other than sending it to Contax Japan for a fix-up.

I personally would choose the 70-200 over the 70-300 simply because of the consistent quality. If you get a good sample of the 70-300 it will perform just as good optically as the 70-200 and maybe even more reliable, with a very useful macro mode and a more metallic construction to boost, but if you do not have the opportunity to cherry-pick from a batch, the 70-200 is the much safer choice.

[Duncati]

Of course, it would be TODAY that you post this comment on possible 70-300mm quality and serial number correlation - the day after I bought no. 12682965 and the same day I have sent it for conversion.

Oh well, please feel free to slice it up and use it to garnish the odd Gin & Tonic if it turns out to be a lemon!

With a bit of luck it may turn out to be one that breaks the pattern.

I must admit that I am rather more excited to get the 17-35 and 85 lenses back from conversion in any case, and suspect that the 70-300 may not see as much use as the faster Canon lenses I have around this length.

[lam]

Thanks for info and hope that my 70-300#12687xxx will not be a lemon.
One more question, can we fit canon 100-400 tripod mount collar to N70-300 apeture ring , does it strong enough to attach collar ? Both diameter are the same at 77mm .

[conurus]

Nah, the aperture ring of the 70-300 is made of plastic and may break if clamped on. There is no good spot on the lens to attach a tripod collar.

[lam]

[ManWearPants]

I read this sentence from the below site with interests. What is tis stray light absorbing mechanical element? Is this unique to 70-200 only?

"The Carl Zeiss T* multi-layer anti-reflex coating of lens surfaces, combined with stray light absorbing mechanical elements in the lens barrel, enable brilliant images with vibrant colors. "

http://www.contaxcameras.co.uk/digital/nlenses/variosonnar70200.asp

[conurus]

We are introducing changes to deal with the 70-300 lemon situation.

If the lens zoomed to 300mm performs well wide open, then it is not a lemon. So, to test it, we can just hold the lens in front of a Canon digital camera body, and use LiveView 10x to manual focus the lens. For such a long focal length of 300mm, exact film-to-flange distance is unimportant, but if you are obsessed with it, the bayonets of the 70-300 should leave a 0.85mm gap before touching the bayonets of the Canon camera body, in order to create a 4.00mm difference in film-to-flange registration distance.

Armed with a way to test the performance of the lens, we will perform this test on every incoming 70-300 from now on. If your lens fails this test, it will be forwarded to Contax Japan for a repair estimate.

This additional test is for the 70-300 only, as the other lenses all perform very consistently. All lenses will still be tested for proper AF and stopping down.

If you are sourcing a 70-300 yourself from the used market, you may also use the same test procedure yourself, and return the lens to your seller if it is found to be a lemon. (You even have a test file as a basis of your claim.) We are posting 100% crops from both a good 70-300 and a lemon 70-300 on a 5D mark II. Compare your test results with our 100% crops. Only a small percentage of 70-300's are lemons but don't be a victim. Check your seller's return policy and test your 70-300 carefully.

In addition, we purchased a pretty big lot of 70-300 and we are going to convert only the non-lemons and sell them from conurus.com in October.

[conurus]

The second 100% crop came from a (still unconverted) 70-300 I purchased from KEH in Atlanta, GA, United States. There are 5 lemon 70-300's that I know of, and at least 3 of them came from KEH. You are likely to get a good working 70-300 from KEH, but statistically they have a high defect rate. Other products from KEH appear fine.

No matter who you bought from, we strongly recommend optical testing your 70-300 before sending it to us for conversion and return any lemons back to the seller.

Duncati and Iam,

Your 70-300's passed our newly introduced optical tests. They looked like the first 100% crop.

[Duncati]

Thanks for the postscript to set our minds at rest, letting Iam and I know that at least our particular fears of having landed a Lemon are at an end.

[gatorine]

Another example of your stellar customer service. I'll rest easier while I await the conversion of my 70-300 knowing that you've already checked both the AF motor and the sharpness of the lens.

Do you have any previous experience with Contax Japan on this particular repair? Can you give us an idea of how much focus adjustments for this lens typically cost?

[lam]

[huhging]

I've never had problem with my N70-300 ...