Upgrading EOS 350D or changing to full frame for low-light improvement?

Question

My question is as follows: In 2006 I bought a Canon EOS350D with a Tamron 18-200, which was a great choice for shooting pictures on vacations, not having to carry around much, etc. Now, this seems obviously not the best choice for taking low-light pictures without flash. Here is an example with ISO 1600 and quite some noise.

I now think about upgrading my camera/replace it to improve the low-light performance. Two strategies showed up when browsing the web (both quite expensive):

• Many seem to "Canon EF 24-70mm f/2.8L II USM" (about 2000€). (Will it be compatible?)
• Another strategy seems to be bying a full frame like Canon EOS6D (about 1700€). Here my old lenses will not be compatible, so I'll need a new one, the above one would be perfect, but unfortunately not in my budget. What would be possible then (but already slightly over my budget) is the Canon EF 24-105mm f/4L IS USM (1200€)

What would be preferable of the above two options? Do you have other suggestions, especially with lower budget (around 1000€), e.g. would it be worth upgrading to the Canon EOS 700D?

Additional information: I also own a Sigma 10-20. The pictures of the series from which the above picture is taken had focal length 18-95. If you need more additional information, please ask in the comments.

Answer 1

Here's the dilemma for someone in your situation: Upgrading the camera will have much less of an impact than it could when still using your current lens, yet upgrading the lens when still using your 350D will limit the improvement as well. I think the lens needs the improvement first, and here is why:

• Lenses with more than a 3X ratio between the shortest and longest focal lengths have many design compromises. In addition to distortion and chromatic aberration, narrow apertures are common with these lenses. For not much more than the EF 24-105mm f/4L IS you are looking at you can buy the Tamron AF 24-70mm f/2.8 Di VC. It is a little sharper than the original Canon 24-70mm f/2.8 L and is both sharper and a stop faster than the 24-105. Your image quality will improve considerably, even with the 350D.
• Although there has been a lot of improvement in high ISO/low noise performance in low light, in the Canon realm most of it at the sensor level has been on the full frame side of things. I own a Rebel Xti/400D, a 50D, and a 7D. In terms of low light performance, there isn't a lot of difference between any of those APS-C models when compared to the clearly superior 5D Mark II. This is particularly true when I use the NR tools in today's software versions on RAW files captured with the older bodies instead of comparing the output from the newer models to shots from the older cameras processed by the older versions of the software. Canon traded the improvements in their Digic processors and firmware/software's noise reduction ability for the smaller pixels used for increased resolution. Your 350D has a sensor with pixels that are 6.4µm wide, comparable to the 6.4µm pixels on the 5D II. The current crop of APS-C Canon bodies, from the Rebel T2i to T5i, the 60D, and the 7D are all based on the same sensor with 4.3µm pixels. The biggest difference between those models are the focus systems, handling speed, and video capabilities - not the basic image quality. If you are intent on upgrading to a Canon APS-C body, I would encourage you to wait until Canon releases a new body with the next generation APS-C sensor. It is long overdue!¹

To get really good low light performance in an environment like your example picture, you're going to have to forget zoom lenses altogether and go with a fast prime lens and a full frame body. Other than the sweet spot around 50mm (due to the way lenses can be designed for cameras with the typical flange distances of DSLRs), wider aperture lenses get expensive very fast. The further away from 50mm you get, the more expensive lenses with comparable apertures become.

If you are serious about improving your low light performance capability on the budget of what an EF 24-105mm f/4 L IS costs, I would suggest looking at used FF bodies like the original 5D and fast primes such as the EF 85mm f/1.8 or the EF 100mm f/2. For 50mm I like the f/1.4² and feel the faster auto-focus and more usable manual focus as well as the durability are worth the difference. Others feel the f/1.8 is a better value. Be sure to buy from reputable dealers like B&H or through places like amazon marketplace where you have recourse if someone sells you a lemon.

_{¹ Canon's release of the 80D in 2016 finally gave Canon shooters an APS-C sensor with better low light performance.
² When Canon introduced EF 50mm f/1.8 STM they corrected most of the shortcomings of the older EF 50mm f/1.8 II. I would even recommend it over the EF 50mm f/1.4 for the vast majority of users (including myself if I were in the market for a new 50mm prime for less than $1,000).}

Answer 2

For modern SLRs, ISO1600 is not that much of a problem. A lot has happened since 2006 - cameras, such as all technology, evolve.

Now I also think sales advice per se is not generally well liked here, so I will try to be general on the topic of upgrading:

The problem: An old camera no longer suits the user's need, what should be focussed on when upgrading.

1. Does the user require old lenses to be compatible? If yes, only the newest models with APS-C sensors will be a viable option if the user had an APS-C camera.

2. The user is able to upgrade all equipment and so may buy any SLR including lenses.

If 2) applies, there are other points to focus on:

• A full frame sensor will give a shallower depth of field - some people have issues with it, but it allows the medium of photography to be used to its fullest extent. How important is depth of field control to the user?

• One loses "reach" with a full frame sensor as it offer a wider field of view on an identical focal length. This can be an issue if the user carries forward lenses. For example, a 50mm lens on an APS-C sensor camera will give the same field of view as an 80mm lens on a full frame camera. (Canon APS-C with 1.6 crop)

• In general full frame will offer better higher ISO performance in the same sensor generation due to larger pixels. However over different sensor generations (!!) it may no longer hold an advantage and total image noise should also be compared if resolutions are significantly different. (What looks like more per pixel noise might look very similar in the context of the full image.)

The last point worth considering: Lenses "age" as well. Professional lenses are getting better, but the improvements are most significant with entry level lenses. Better lenses can be manufactured at ever lower prices. An old lens might not have the resolving power to fully benefit from a newer higher density sensor and might be best replaced too. A newer camera may produce disappointing results if the limiting factor is the lens.

Answer 3

Full frame sensors have about twice the surface area as APS-C sensors, which, at the same technology level, gives about a one-stop advantage. The current generation of sensors is very good, and at higher ISOs will have much more than a two-stop advantage over a seven-year-old model.

That is, full-frame will have a real advantage, but it's not necessarily the most cost-effective way to get a meaningful improvement. That's especially the case if you have a real-world budget and the same money could go to better lenses.

Answer 4

If you have doubts about it, then you probably don't need a full frame camera.

The Sigma 10-20mm (either version) is a really nice (although not very expensive) lens, if only for that I'd stick with an APSC camera, maybe the new 70D, and it would still be much cheaper than a complete change to FF.

Or go really cheap and get a tripod!