100-400L/70-300L Decision

[SynJohn]

Hi All,
New to this forum obviously but not to photography or forums for that matter. I am looking for input from people on a choice I am thinking about. Let me see if I can condense this down.
Currently I have the 70-300L and a 5DII, the 5DII was upgraded(changed) from a 7D 1 year ago and I have had the 70-300l about 18 months or so.
Last month while shopping at BestBuy with the wife I scored a NIB 70-200F2.8L II for $1499. (long story). With that lens in my bag now I am thinking of getting rid of the 70-300L in favor of a 100-400L. Since getting the 5D I am missing the long end and the extra 100mm does not seem to be worth the expense of keeping this lens since getting the 70-200L.
I am thinking of finding some one local that would want to trade a 100-400L for my 70-300L which also has the Canon tripod mount with it.
Does this seem like fair trade both monetarily and by IQ? This is of course based on the idea that someone is wanting to downsize from a much larger physical lens and do a trade. I would also want to do this only for a newer date coded 100-400L.

Thanks for your input

John

[andnowimbroke]

Is the wife going to be using the lens too, or is it just for you? She might prefer the smaller package. And, have you thought about just selling the 70-300 and getting a 1.4 tele to use with the 70-200? Some don't like it because of the way the converter attaches, but it would get you about 280mm with a better f-stop and have money in the bank. I don't have a good "cheap" way to get to 400mm besides another teleconverter, a cheaper crop camera tied to the current lens you have for the appearance of a longer length, or the swap you were talking about. The problem with the swap is that all you're getting is an older, bigger, heavier lens, and an extra 100mm. The bad thing about 400mm is it's not 500mm and that's what you'll be looking at next

[HDNitehawk]

Consider the 2x extender with your 70-200mm instead.

You only gain the long reach of the 100-400mm, it is behind the 70-200mm everywhere else.
If all your shots are at 400mm, look at the long primes.

[SynJohn]

Thanks for the replies,
Yes my wife will use it on occasion but that would only be sitting out back taking pictures of squirrels and hummingbirds. She has no qualms about the weight of the 70-200L but does prefer 70-300L.
Maybe a tele is the right choice for short term and look into a used prime. I have considered the 400MM 5.6 but the MFD and lack of IS was a deal breaker.
Living in Seattle we are low light shooters 250+ days a year so IS is important to the types of shooting we do.
There is a local rental store to get both the 1.4 and 2x tele convertors. Maybe I should try this for a weekend.

Again thanks for the input and ideas.

John

[HDNitehawk]

Make sure if you rent the tele converters you get the newer III versions

[neuroanatomist]

If you need the reach of 400mm, the 70-200 II + 2xII/III will rival the IQ of the 100-400mm (slightly lower in the lab, probably not different in the real world). The 70-200 + TC combo is also weather sealed, likely relevant in the PNW.

[SynJohn]

Next weekend I am going to rent both the Teleconverters and give them a shot. Hopefully we will have at least a few hours of sun so that I can test in both conditions.
I will touch back here for results or further ideas if this is not going to work for me.

Thanks

[HDNitehawk]

I'll give a few more thoughts.
The 70-200mm has 4 stops of IS. The 100-400mm has 2 stops of IS. Low light this will be important.
In every other aspect except 400mm the 70-200mm will give you better IQ and better stabilization.
Comparing the IQ at 400mm for both the IQ of the 400mm is slight over the 70-200mm;

http://www.the-digital-picture.com/R...mp=7&APIComp=2

One of the improvements that you will see with the 70-200mm is the improvement made my the newer coatings used on it. Improved color is one of the benifits. The 100-400mm is an older lens and is due for replacement, it doesn't have some of the latest technology incorporated in it.

Another thought I would have in your situation is to buy both the teleconverter and the 400mm f/5.6. B&H has this lens for $1199, the 100-400mm is $1459 and the difference would go a long way to pay for the tele convertor. (you have to put the lenses in cart to see the actual sell price). The logic would be on sunny days when you have a shutter speed over 1/1000 or you are using a tripod you could use the 400mm, at other times use the 70-200mm.

The 400mm f/5.6 gives you the best IQ option.

http://www.the-digital-picture.com/R...mp=0&APIComp=0

It might be good to rent a 100-400mm if you can to see the differences.

[clemmb]

I'll give a few more thoughts.
The 70-200mm has 4 stops of IS. The 100-400mm has 2 stops of IS. Low light this will be important.
.

4 stops @ 200mm. I wonder what it is with 2x so you are @400mm.
Low light is important for hand holding but also for subject movement. IS will not help with subject movement. Using a 1.4x giving an f4 @280mm will probably be better than 300mm @ f5.6.

[HDNitehawk]

4 stops @ 200mm. I wonder what it is with 2x so you are @400mm.
Low light is important for hand holding but also for subject movement. IS will not help with subject movement. Using a 1.4x giving an f4 @280mm will probably be better than 300mm @ f5.6.

Do you think it drops progressively with length?
Actually I have never seen an article or a discussion if a tele convertor affects IS.

I didn't know we were talking IS for subject movement, just low light situations.