70-200 f/4L + 1.4x vs. 75-300 USM III

I suspect that I know the answer already, but I was wondering how the image quality would compare between these two options? If I am correct in thinking that even with the 1.4x extender on, the L set-up would blow the cheapie 75-300 out of the water at all focal lengths and aperatures, is there any reason to keep the 75-300, or should I sell it ASAP? (I thought about keeping it for its size and weight compared to the bigger glass, but then think that if I am going to be packing the SLR and not a P&S, I should keep the best glass on it that I can.)

I might try a side-to-side test, just for kicks. Any thoughts? Should I keep (as lightweight backup) or sell the 75-300?

I have seen online comparisons between these two and the 75-300 does seem to allways come out looking 'pretty good considering'
...Of course in actual use it's a totally different story.The 70-200/4+TC will get a high percentage of keepers while the 75-300 is nothing like that

Have you seen this review? It doesn't mention that TC but it has lens comparisions with the F4 and 75-300.

I would keep the 75-300 (as I have) as you probably won't get much for it anyway! I use mine on occasions when I don't want to get the L out (environment conditions). If it's kept away from 300 (I stick at 200, as far as my L anyway) then the quality is ok after a bit of post touch-up.

I see little point in fitting a lower grade lens to your SLR when you own a better one that covers the same range. That smacks of masochism...

I can understand using the cheap lens in really nasty weather, (sandstorm, sleet, hail, nuclear fallout), due to the cost of the L. Go ahead and sacrifice the throw-away and keep the L in the velvet lined, platinum clad, diamond encrusted case

Not at all sure about that ... I tracked the cheaper zoom lenses for a couple of weeks waiting for a bargain on ebay. The 75-300 regularly got over £100 and even beyond £130 on occasion. This is crazy as they can be had for that price new via 7dayshop
... even the USM.

Of course, depend how much was paid for it originally. The poster may even make money on it I just can't see the point keeping it. Get the extender with the money instead ... I'm doing that, currently selling my 70-300 Sigma to pay for it (at no loss!) and then using it with my SH 70-200 F4 L.

Living in Scotland, the environment conditions are always against you .

You've nearly convinced me that I should buy cheap lenses and leave my L glass in my display cabinet next to my classic rangefinder collection .

The L series lenses are designed for professional use and are expected to take a certain amount of "abuse". They're not intended for a cosseted life.

Easy for you pros to say with big budgets! My 75-300 cost me £150 14 years ago, I would love someone to offer me £100 for it!

You thought I was serious?

As an amateur, and had to save up hard to afford a second hand 70-200mm f4 L and 1.4x TC Mk I. Still have my 75-300mm, but never used it again since I got the 70-200mm, so it'll go on eBay this weekend.

Gave the 70-300mm III USM to my dad for his 60th birthday.

Were both happy .

The 'L' lenses are weather sealed, while the 75-300 is not.

I would suspect that is actually a reason more to use them in adverse conditions, as the risk to damage the lens is actually smaller.

Best regards,
Andy

Not strictly true. SOME L series lenses are weather sealed, by no means all. The EF 70-200mm f/4L is NOT so don't go using it in a downpour and assuming you're safe.

condyk wrote:
Not at all sure about that ... I tracked the cheaper zoom lenses for a couple of weeks waiting for a bargain on ebay. The 75-300 regularly got over £100 and even beyond £130 on occasion. This is crazy as they can be had for that price new via 7dayshop
... even the USM.

Of course, depend how much was paid for it originally. The poster may even make money on it I just can't see the point keeping it. Get the extender with the money instead ... I'm doing that, currently selling my 70-300 Sigma to pay for it (at no loss!) and then using it with my SH 70-200 F4 L.

75-300 mk3 usm at 7day shop is £119 and yoy are right ive seen the go on ebay for £130 plus.

When it comes to saving and making cash I'm not often wrong

So, JusSmith, you know where to sell your 75-300 now! Nice picture, good description, good selling record and you're sorted.