Your aperture wouldn't change between crop and FF cameras, but the FF may give you better ISO performance depending on the model. As you already observed, the 'equivalent focal length' or angle of vision is different by the crop factor.

Repleo, in the interest of clarity, let me pose my question a little differently: Had I had a good FF frame Canon (since my 60D is a Canon, etc.) if I had moved the 50mm lens(FF), (I could not move the 24mm as it is a crop factor lens) to a FF Canon body, set in manual with the same settings as I had made on the 60D, and at the same distance from the subject, would I have had better light gathering ability and if so why? I am aware that the 50mm on a FF would have been wider angle than on the 60D (by the crop factor of 1.6) but I am addressing light gathering ability as to aperture....perhaps in other words......we all know that 50 mm on a FF is equivalent to 80mm on a Canon crop (50mm X 1.6=80mm). BUT would the 1.8 app on the FF still be the equivalent of 1.8 on the crop or would it really be the equivalent of 1.8 X 1.6 =2.8 on the crop?????? Or are you telling me the effective aperture as well as shutter speed would stay the same but the ISO float being adjusted by the camera automatically would give me a lower ISO on the FF than on the CROP? And if so, why is that? Sorry if I am being dense but I am really trying to fully understand this. Thanks to all who are knowledgeable and will comment back on this.....

OH.....................I may have just had a mental break through!! Or then maybe not, lol.........Repleo, I have come up with what I believe is correct and what you are trying to tell me......lets see if I am on it or not.......the field of view changes by the crop factor since I am remaining the same distance from the subject with the two cameras.....the aperture is unaffected by the crop BUT, because the FF lense is larger in diameter, that additional diameter in the lense gives me greater light gathering ability with the FF, hence, the camera can select a smaller ISO than on the crop.....and that is why the FF will always be able to give better light gathering ability than a crop once you get to the point that a wider aperture lens for the crop becomes either unavailable or unaffordable.........am I correct or am I still all wet?

Hi
This is my first time asking a question. I have been reading UHH for over a year. I am serious amateur photographer. I am wondering which brand of 77mm ND 10 stop filter would you suggest. I am using a Nikon D750 with a number of Nikon lens. I have step down rings to attach the filter to other size lenses. I already own 6 stop Cokin filter but it requires an adapter and the use of the seal which is rather cumbersome for outdoor photography.
Does anyone have experience with Breakthrough 10 stop ND filter, if I would like to hear from them as well as others who may have compared this filter with others. Or would you recommend any other brand over Breakthrough.
Thanks.

Last night I was shooting my grandson's 4th birthday party. Flash photography was decidedly out as the only thing I had with me was the built in flash on my Canon 60D, a 1.6 crop factor camera. That simply made the photos too bright and harsh and negated the decorated theme of dim light and overall ghoulishness (assuming that is even a word).

Knowing I would be working with very dim light, I set my camera on manual with a shutter speed of 1 80th of a second (four year old boys can run pretty fast), aperture at 1.8 on my Canon 50mm prime lens and let the ISO float to 6400 after which the light would be reduced. With fast moving 4 year olds, I decided a tripod would be too slow so I did not take one with me.

Over all the shots were not too bad.....not to good either unfortunately, but many were acceptable.

Inside close quarters the 50mm got a little long with the crop factor so I decided to go to my 24mm prime 2.8. Have not had the 24 very long so I got to compare them side by side in low light. The 24 mm was definitely better in terms of focal length, but many more of these pictures were simply too dark to be worth much......the difference between the 1.8 and the 2.8 obviously.

My question is basically two fold:

First, had I been using a FF camera which I am still considering obtaining, would my aperture have been reduced by the crop factor giving me more effective aperture than I was obtaining with my current crop factor camera??? If so that would be a tremendous gain in terms of low light performance.

Second, from you advanced amateurs and certainly from you professionals, what else could I have done to improve my image quality in this situation based on your own personal experiences? Thank all of you for your input!

(I previously researched this last part of my question on the web and found that there seems to be opinions on this topic that do contradict each other, to say the least....I am confused on this issue but would really like to know as it will impact my decision as to purchasing a FF camera).